Lee v. Amazon.com, Inc.

Filed 4/8/22 (unmodified opn. attached)

CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION TWO

LARRY LEE,
Plaintiff and Appellant, A158275

v. (Alameda County
AMAZON.COM, INC., Super. Ct. No. RG14738130)
Defendant and Respondent.
ORDER MODIFYING OPINION
AND DENYING REHEARING
[NO CHANGE IN JUDGMENT

THE COURT:
It is ordered that the opinion filed herein on March 11, 2022, be
modified as follows:
1. On page 4, second line of first full paragraph, delete the words
“purchased from Amazon.”
2. On page 4, at the end of the first full paragraph, add the following
new final sentence:
The Monsepa sample tested was purchased from
aztopselstore.com and appears to be the same as the Monsepa
product available from Amazon; the other four samples tested
were from products purchased from Amazon.
3. On page 11, first and second lines of last partial paragraph, delete
the word “the” before “product page” and replace it with “Amazon’s,” delete
the word “the” before “Monsepa,” and delete the words “Lee had tested.”
These lines should read:

1
 Steinberg was shown a customer comment on Amazon’s product
page for Monsepa cream saying the news had reported on
January 9, . . .
4. On page 12, second line of second partial paragraph, after “health
risks from,” delete the words “chemical exposures,” and replace with
“exposure to chemicals including mercury,”
5. On page 12, delete everything after the first sentence of footnote 15
and replace it with the following:
He had taught part of a course on risk assessment at San Diego
State University School of Public Health for about 20 years,
worked with governmental committees on developing and
defining methods to assess health risks, and performed more
than 200 Proposition 65 risk assessments, of which more than 50
involved metals, more than 50 involved chemicals listed as
reproductive or developmental toxicants, and “[a]lmost all” had a
component of “generalizing data to the population of the products
that we used.” Sheehan had experience evaluating mercury
exposure in the contexts of site risk assessment, waste disposal,
and a project involving removal of gas pressure regulators from
homes.
6. On page 18, delete footnote 16, and on page 28, delete footnote 19,
which will require renumbering of all subsequent footnotes.
7. On page 28, first line of first full paragraph, delete the word “five”
and replace with “four.”
8. On page 28, second line of first full paragraph, after the words “Web
site” add the following: “, as well as a fifth such product that appears to be
available for sale on the Web site,” The first two lines should read:
Given the undisputed evidence that samples of four skin-
lightening products purchased on Amazon’s Web site, as
well as a fifth such product that appears to be available
for sale on the Web site, contained high levels of mercury as . . .
9. On page 80, second line of second full paragraph of “DISPOSITION”
section, add the word “four” before “products.”

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 10. On page 80, at the end of the second full paragraph of the
“DISPOSITION” section, add the following new final sentence:
As to the fifth product tested for this case, the trial court shall
determine whether the Monsepa product available on Amazon’s
Web site was in fact the same product as the one tested.
11. On page 80, after the second full paragraph of the “DISPOSITION”
section, add the following new third paragraph:
If any violations of Proposition 65 are established, the court shall
determine the appropriate remedy in accordance with section
25249.7.
There is no change in the judgment. The petitions for rehearing are
denied.

Dated: __________________ _________________________
Richman, Acting P.J.

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Trial Court: Alameda County Superior Court

Trial Judge: Hon. Robert McGuiness

Attorney for Plaintiff and Appellant Law Office of Jonathan Weissglass
Larry Lee: Jonathan Weissglass

Greenfire Law
Rachel S. Doughty
Jessica L. Blome

Attorneys for Amicus Curiae on behalf Rob Bonta
of Plaintiff and Appellant: Attorney General of California
Dennis A. Ragen
Roxanne Carter
Deputy Attorneys General

Attorneys for Amicus Curiae Danielle R. Fugere
As you Sow on behalf of Plaintiff Chelsea J. Linsley
Appellant:

Attorneys for Amicus Curiae Altshuler Berzon
Center For Food Safety on behalf Barbara J. Chisholm
of Plaintiff and Appellant: P. Casey Pitts

Attorneys for Amici Curiae Black Environmental Law Clinic
Women for Wellness and the Mercury Mills Legal Clinic at Stanford Law School
Policy Project/Tides Center on behalf Deborah A. Sivas
of Plaintiff and Appellant: Molly Loughney Melius

Attorneys for Defendant Doll Amir & Eley
and Respondent Amazon.com, Inc.: Gregory L. Doll
Brett H. Oberst
Jamie O. Kendall
Lloyd Vu

Attorneys for Amicus Curiae Law Office of Fred. J. Hiestand
The Civil Justice Association of Fred J. Hiestand
California on behalf of Defendant
and Respondent:

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Filed 3/11/22 (unmodified opinion)
CERTIFIED FOR PUBLICATION

IN THE COURT OF APPEAL OF THE STATE OF CALIFORNIA

FIRST APPELLATE DISTRICT

DIVISION TWO

LARRY LEE,
Plaintiff and Appellant,
A158275
v.
AMAZON.COM, INC., (Alameda County
Super. Ct. No. RG14738130)
Defendant and Respondent.

Under legislation enacted as Proposition 65 in 1986, businesses are
prohibited from knowingly and intentionally exposing any individual to
certain chemicals without first providing a warning. Lee seeks to hold
Amazon.com, Inc. (Amazon) accountable for offering on its Web site, without
warnings, certain skin-lightening face creams sold by third parties and
alleged to contain mercury. The trial court concluded that Amazon is
immune from liability under the federal Communications Decency Act (CDA)
and also that Lee failed to establish several elements of his case under
Proposition 65.
Lee maintains Amazon is not protected by the CDA and the trial court
erred in its view of the evidence required to establish the alleged statutory
violations.

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 We agree with Lee and, therefore, will reverse and remand for further
proceedings. 1
BACKGROUND
California’s Safe Drinking Water and Toxic Enforcement Act of 1986
(Act) (Health & Saf. Code, § 25249.5 et seq.), adopted by voter initiative in
1986 and commonly known as Proposition 65, provides, “No person in the
course of doing business shall knowingly and intentionally expose any
individual to a chemical known to the state to cause cancer or reproductive
toxicity without first giving clear and reasonable warning to such individual,
except as provided in Section 25249.10.” (Health & Saf. Code, § 25249.6.)
Mercury and mercury compounds were listed by the state as reproductive
toxins under Proposition 65 in 1990. (Cal. Code. Regs., tit. 27, 2 § 27001,
subd. (c); see Health & Saf. Code, § 25249.8.) 3

1 The Attorney General filed an amicus brief in support of Lee pursuant
California Rules of Court, rule 8.200(c)(7). Exercising his authority to
represent the public interest, the Attorney General explains he has a “special
interest in the proper interpretation and enforcement of” Proposition 65 as
the “public official with statewide authority to enforce” the Safe Drinking
Water and Toxic Enforcement Act of 1986 and “the only public official with
authority to review and comment on settlements entered into by private
enforcers under Proposition 65.”
Additionally, we granted applications to file amicus briefs from several
nonprofit organizations whose missions relate to the subject matter of this
case. We have received amicus briefs on behalf of Lee from As You Sow and
Center for Food Safety, Black Women for Wellness and the Mercury Policy
Project/Tides Center, and on behalf of Amazon from the Civil Justice
Association of California.
2Further references to “Regulations” are to title 27 of the California
Code of Regulations except as otherwise specified (e.g., Regs., § 25102).
3Under California law, a discarded substance is “hazardous waste” if it
contains 20 milligrams per kilogram, 20 parts per million (ppm) or more of

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 Cosmetics containing one ppm (0.0001 percent) or more of mercury are
prohibited under federal law. (21 U.S.C. § 331(a)–(c); 21 C.F.R.
§ 700.13(d)(2)(i).) 4 According to the FDA, “[t]he toxicity of mercury
compounds is extensively documented in scientific literature. . . . Mercury is
absorbed from topical application and is accumulated in the body, giving rise
to numerous adverse effects. . . . [C]hronic use of mercury-containing skin-
bleaching preparations has resulted in the accumulation of mercury in the
body and the occurrence of severe reactions.” (21 C.F.R. § 700.13(b).)
The present case concerns four brands of face creams advertised as
skin-lightening or skin-whitening products: Faiza, Face Fresh, Monsepa, and
Meiyong.
Lee’s second amended complaint listed 27 products offered for sale on
Amazon’s Web site under these brand names, identified by individual product
name or description and “Amazon Standard Identification Number” or

mercury. (Cal. Code Regs., tit. 22 §§ 66261.2, subd. (a), 66261.20, subd. (a),
66261.24, subd. (a)(2)(A).)
4 Federal law prohibits “[t]he introduction or delivery for introduction
into interstate commerce of any . . . cosmetic that is adulterated or
misbranded,” the “adulteration or misbranding of any . . . cosmetic in
interstate commerce” and the “receipt in interstate commerce of any . . .
cosmetic that is adulterated or misbranded, and the delivery or proffered
delivery thereof for pay or otherwise.” (21 U.S.C. § 331(a)-(c).) The Food and
Drug Administration (FDA) regards “any cosmetic containing mercury” as
“adulterated” unless it contains “no more than a trace amount of mercury and
such trace amount is unavoidable under conditions of good manufacturing
practice and is less than 1 ppm (0.0001 percent), calculated as the metal”
(21 C.F.R § 700.13(d)(2)(i)) or it is “intended for use only in the area of the
eye, it contains no more than 65 ppm (0.0065 percent) of mercury, calculated
as the metal, as a preservative, and there is no effective and safe
nonmercurial substitute preservative available for use in such cosmetic.”
(21 C.F.R. § 700.13(d)(2)(ii).)

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“ASIN.” 5 His pretrial brief subsequently reduced the list of products at issue
to 11, identified by ASIN and name or description: Three by Faiza, one by
Face Fresh, one by Monsepa, and six by Meiyong. 6
Lee had laboratory tests performed on samples of these products
purchased from Amazon, which found 15,000 ppm mercury in a sample of
Monsepa Express Peeling cream (ASIN B0030K8GJY) tested in 2017, 9,600
ppm of mercury in a sample of Faiza Beauty cream (ASIN B00WORM8R0)
tested in 2016, 5,600 ppm of mercury, in a sample of Face Fresh Beauty
cream (ASIN B00ZP38YQY) tested in 2015, 21,000 ppm of mercury in a
sample of Meiyong Seaweed Super Whitening cream (ASIN B00CVJKBDE)
tested in January 2015, and 2,000 ppm of mercury in another sample of
Meiyong Seaweed Super Whitening cream (ASIN B008XRYQUM) tested in
September 2015.
Several samples of Monsepa creams (not purchased from Amazon) had
previously been tested for California agencies: Tests performed for the

5The ASIN is an internal code assigned by Amazon to each unique
product listed on the Web site.
6The 11 products were: “Original Faiza Beauty Cream Whitening
Cream Anti Pimple Cream Freckle Cream” (ASIN B00WORM8R0), “Faiza
Beauty Cream/To Remove Freckles & Dark Spots” (ASIN B00V0LHLTM),
“Faiza Beauty Cream – 30 gram – Whitening Cream ‐ Anti Pimple Cream –
Freckle Cream” (ASIN B00XUY6FL6), “Face Fresh Beauty Cream” (ASIN
B00ZP38YQY), “Monsepa Express Peeling Remove Dark Sports Face Cream”
(ASIN B0030K8GJY), “Meiyong Super Extra Whitening Cream Seaweed Face
Lift Natural Algae” (ASIN B00CVJKBDE), “Seaweed Cream – Extra
Whitening & Face Lift” (ASIN B008XRYQUM), “Meiyong Seaweed Extra
Whitening Formula & Face Lift Cream” (ASIN B00AS71WWU); “Seaweed
Cream – Extra Whitening & Facelift” (ASIN B00UPXPMYQ), “Meiyong
Brand Super Extra Whitening Cream Seaweed Face lift” (ASIN
B00VCN3Z7Y), and “Meiyong Super White Cream Extra Whitening & Face
Life Advanced Super Revitalizer” (ASIN B00HZFSBYU).

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California Department of Public Health (CDPH) found 8,900 ppm mercury in
a sample of Monsepa Express Peeling cream tested in May 2013, 13,000 ppm
mercury in a sample of Monsepa Express Peeling cream tested in December
2013, and a 2013 test for the California Department of Justice found 12,000
ppm mercury in a sample of Monsepa Express Peeling cream and 20,000 ppm
mercury in a sample of Monsepa Whitening Peel.
Additionally, in 2013, the European Union’s Rapid Alert System for
dangerous non-food products (RAPEX) issued two alerts for Faiza Beauty
Cream, one reporting 5,430 ppm mercury and the other reporting 5,940 ppm
mercury, and an alert for Face Fresh Beauty Cream reporting 4,620 ppm
mercury.
The CDPH issued a health risk warning on January 14, 2014, for
certain imported skin-lightening creams that had been found to contain high
levels of mercury, including “Monsepa Bleaching Express Peeling.”
Lee provided Amazon a 60-day “Notice of Violation” pursuant to
Proposition 65 (Health & Saf. Code, § 25249.7, subd. (d)) dated May 22, 2014.
He filed his complaint for civil penalties and injunctive relief on August 25,
2014.
After a bench trial in January 2019, the trial court ruled in favor of
Amazon, finding the company immune from liability under section 230 of the
federal CDA (47 U.S.C. § 230). 7 The court also found that while Amazon
could have a duty to warn under Proposition 65 for third-party sales of the
products at issue, Lee failed to prove each element of his claim under
Proposition 65—specifically, that Lee did not prove each of the products at
issue contained mercury, that test results finding mercury in a unit of the
products at issue should be generalized to other units of that product or

7 Further references to “section 230” are to title 47 United States Code.

5
similar products, that the creams sold on Amazon’s Web site were actually
used by consumers, and that Amazon had actual knowledge the products
contained mercury at the time they were purchased without a Proposition 65
warning.
Mercury in Skin-Lightening Creams
As described by Lee’s expert witness on mercury in skin-whitening
creams and resultant health risks, Dr. Gina Solomon, 8 mercury exists in
three forms (elemental, inorganic and organic), all of which are toxic, with
serious effects on bodily systems and organs at a cellular level. Inorganic
mercury (the form used in skin creams) is “very, very toxic” to kidney
function and also has serious effects on reproductive function and fetal
development. Animal studies consistently show reduced fertility, fetal
viability and birth weights at “pretty low level exposures.” In both humans
and rodents, prenatal exposure at “pretty low levels” has been shown to
result in profound deafness. Solomon testified that the levels of mercury
found in skin creams are in the same range as those shown to cause these

8 Dr. Solomon was a principal investigator at the Public Health
Institute and clinical professor in the Division of Occupational
Environmental Medicine at the University of California San Francisco. Her
background included serving as the deputy secretary for the California
Environmental Protection Agency, where her work included developing
sampling plans for hazardous material cleanup, including work with metals
such as lead, mercury and arsenic, and extensive work with OEHHA on
Proposition 65 issues; teaching medical students, residents and fellows, and
supervising them on clinical work regarding complex toxicology issues;
teaching continuing medical education classes for doctors and developing the
original curriculum for a CDPH program for physicians on the human health
effects of mercury; and treating patients exposed to dangerous levels of
mercury from a skin cream product and collaborating with researchers
investigating the case, which led to the CDPH’s health alert on mercury in
skin-lightening creams, as well as work on the issue with other states’ health
departments.

6
adverse effects in rodents, which tend to be less sensitive than humans to
many neurologic and reproductive effects.
The adverse effects of mercury are not limited to the direct users of the
creams. The form of mercury used in skin-lightening creams—inorganic
mercury—can release mercury vapor, especially in warm conditions. 9 The
CDPH has found mercury contamination resulting from use of skin creams
requiring extensive decontamination of houses, including items such as
washing machines, mattresses and sofas, and disposal of items like toys,
towels, and bedding as hazardous waste. In the case of a family Solomon
treated for mercury poisoning, mercury vapor was found emanating from the
hands of the woman who used the cream, and decontamination of her hands
took a month of repeated applications of a binding compound.
The primary users of skin-lightening creams are women, principally
women of color. At the time of trial, the CDPH was conducting educational
events in communities where the creams are known to be used, as well as a
buyback program for people to return the creams and receive money to
purchase substitutes.
Not all skin-lightening creams contain mercury: CDPH tests of more
than 100 skin-lightening creams found seven that were positive for
mercury. 10 Of a total of five ingredients known to whiten skin, the only one
permitted in the United States is hydroquinone.

9 Solomon explained that mercury exists in three different forms
(elemental, inorganic and organic), which have different properties, but can
“inter-covert” in different settings.
10None of the products tested in this study came from Amazon. The
CDPH witness who testified at trial explained that they were collected from
markets in targeted communities and online stores serving immigrant
populations identified in the literature, or through poisoning investigations,
as using these creams.

7
 Solomon testified that public health issues with skin-whitening creams
involve creams imported from certain countries in Asia, Mexico, and in a few
cases Africa; Lee’s expert witness on cosmetic chemistry and Proposition 65
warnings, David Steinberg, 11 testified that in his experience most skin-
bleaching products containing mercury were made in Pakistan. Both
testified that the claims made on listings on Amazon for the products Lee had
tested—referring to removing dark spots, whitening skin and treating
acne 12—were “red flags” indicating the product was for skin bleaching and

11 Steinberg was the president of a consulting company that deals with
“regulations and chemistry of cosmetics and topical pharmaceutical
products.” His 50 years’ experience in the cosmetic industry included
working on product development involving the chemistry of cosmetics,
advising cosmetics companies on product and regulatory issues, teaching and
publishing on the chemistry of cosmetics, and lecturing on quality assurance
for cosmetics; he had experience with mercury in cosmetics and specifically in
skin-lightening products, and with issues under Proposition 65.
12 On the Amazon Web site, a listing for “Faiza Beauty Cream” (ASIN
B00V0LHLTM) claims to “remove freckles & dark spots”; another—with the
same product image, but a different ASIN (B00WORM8R0) and different
Universal Product Code claims to be “the only cream that cleans pimples,
wrinkles, marks, hives even dark circles under the eyes and turns your skin
white.” The product listing for “Meiyong Super Extra Whitening Cream
Seaweed Face life natural Algae” (ASIN B00CVJKBDE) includes “Help
relieve acne, freckles and dark spots on the performance give a white skin.”
Monsepa Express Peeling Remove Dark Spots Face Cream (ASIN
B0030K8GJY) claims it “eventually removes even the deepest types of
freckles, dark spots, butterfly spatches and yellow spots from your face” and
“is specially effective to eradicate and even out acne scars.” Face Fresh
Beauty Cream’s (ASIN B00ZP38YQY) claims include, “Best whitening
cream,” “Anti Wrinkles,” “lightening dark spots,” and “Turns Your Skin
White.”

8
might contain mercury. 13 This was particularly the case where a product
claimed to both whiten skin and treat acne, because mercury is the only
ingredient known to do both.
Solomon testified that the mercury concentrations found in the creams
tested in this case meant mercury was “definitely not” a “trace amount,” but
rather an intentionally added active ingredient; the concentrations were
“absolutely inconsistent” with mercury being a trace contaminant. The range
of concentrations in the tested samples, between 2,000 and 21,000 milligrams
per kilogram (2,000 to 21,000 ppm or .2 to 2 percent), was consistent with
active ingredients in other consumer products, such as 2 percent of the
herbicide in RoundUp, 1 percent cortisone in anti-inflammatory skin cream
or .2 percent sodium fluoride in toothpaste. Prior to her work on this case,
Solomon had seen the 2014 CDPH press release warning consumers about
mercury in certain skin-lightening creams, including Monsepa, and believed
the product contained mercury because she considered product warnings
from the CDPH highly credible; the test results Lee obtained in 2017
confirmed her opinion and showed the formula had not been changed despite
the health alert.
Based on the test results and language used in the Amazon listings for
the skin whitening creams, Solomon was certain all units of the products
tested would contain mercury. Solomon testified that “very little actual
testing” is necessary to answer the “yes or no” question whether an
intentionally added ingredient is present in a product, and regulatory
agencies “not infrequently” base a decision on a single sample or very few

13Amazon stipulated that all 27 products identified in the second
amended complaint purported to be skin-lightening or skin-bleaching
products.

9
samples. Factors such as how a product was stored and whether multiple
manufacturers were used, could be relevant to a contamination issue, but
would be irrelevant in determining whether an intentional ingredient was
present because manufacturers are reluctant to change their formulas: They
want consistency in the appearance, smell, and effect of consumer products,
as consumers notice differences and do not like them. Solomon was careful to
clarify that extrapolation from test results on one unit to other units of the
same product was appropriate for “yes/no test results” for presence of
mercury, not the exact concentrations detected.
Steinberg similarly testified that the test results in evidence were
sufficient to conclude the products at issue contained mercury because there
was no way the amount of mercury found in samples Lee had tested could be
due to a trace contaminant that might vary between batches or lots; it had to
be a deliberately added ingredient He testified that in making emulsions
(the form of the skin creams at issue), at least three or four tests are usually
run per batch for purposes of quality control and quality assurance, to ensure
uniformity and confirm the product meets specifications and is free of
contamination, and most companies test each batch before filling individual
containers for consumer sales. Testing of multiple batches of each product is
not necessary to determine whether mercury is an ingredient in a cosmetic
product, however, because at levels seen in this case, it has to have been
deliberately added. The high levels of mercury found in the five samples Lee
had tested, together with the products’ claims of skin whitening as the
intended use, made Steinberg “very, very certain” other batches or lots of the
same product would all contain mercury as an ingredient.”
Steinberg acknowledged the possibility there could be variations in the
chemical makeup of the products between batches; that he did not have

10
information about the companies’ specific manufacturing and packaging
practices or know details such as when they began using mercury in their
skin-bleaching products or whether they had another version of the product
that used a different ingredient in place of mercury; and that some companies
use different formulas in different countries for products branded and sold as
the same product. He testified that if a company does not follow “current
good manufacturing procedures” (cGMPs), which include matters such as
manufacturing and testing methods and meeting product specifications, “all
bets are off in terms of product consistency across units and batches and
lots,” and many variables could make a difference in this regard. Steinberg
did not know whether the companies here followed cGMPs, but he had reason
to believe the products were sourced in Pakistan and no reason to expect
companies in Pakistan to follow cGMPs.
Nevertheless, Steinberg testified he could be “very certain” the
products tested here contained mercury without analyzing every package
because “cosmetic-like products” are manufactured in “larger amounts” with
“a consistent formulation,” mercury is the active ingredient, and cosmetic
companies do not like to change formulations of creams “unless it’s absolutely
mandatory, or marketing just absolutely demands it, because it’s very time-
consuming” and a significant added expense. A different chemical could not
simply be substituted for mercury; the product would have to be “totally
reformulate[d]” because the emulsion would not be stable.
Steinberg was shown a customer comment on the product page for the
Monsepa cream Lee had tested saying the news had reported on January 9,
2014, that the product contained high levels of mercury, providing a link to
the official alert on the CDPH Web site, and asking vendors to stop selling

11
it. 14 Steinberg testified he would advise a company that received a comment
like this to immediately find out if there was mercury in the product. He
further testified that as part of good business practices, it is important for a
company offering cosmetics for sale on the Internet to monitor public health
alerts and announcements by governmental agencies. His advice to a client
that received the May 22, 2014, notice of violation Lee sent to Amazon would
be to confirm whether the product it was manufacturing or selling contained
mercury and, if so, recall the product and notify the FDA. Once Amazon was
alerted to the presence of mercury in the creams, it should have immediately
notified every purchaser of the product to discontinue use and halted sales of
the product.
Dr. Patrick Sheehan, Amazon’s expert witness on risk assessment and
evaluation of health risks from chemical exposures, 15 agreed that mercury is
a known ingredient in skin-lightening creams and that in each of the tested
samples in this case, mercury was an ingredient, not a contaminate. He

14 The comment expressed skepticism that the product was made in
France (as was also stated on the bottle and packaging of the sample Lee had
tested) because “the EU has strict cosmetic regulations.” Steinberg had
“serious doubt” the product was made in France based on his experience
dealing with officials in France, who would not have permitted it, and his
knowledge that “these types of products using these types of ingredients . . .
have been restricted almost exclusively to Pakistan.”
15 Dr. Sheehan had worked in the field of risk assessment for 40 years,
the last 19 of which he had been a consultant with a company called
Exponent, advising clients on historic, current, and potential exposures and
associated risks. He had taught part of a course on risk assessment at San
Diego State University School of Public Health for about 20 years, worked
with governmental committees on developing and defining methods to assess
health risks, done more than 200 Proposition 65 risk assessments, and had
experience evaluating mercury exposure in the contexts of site risk
assessment, waste disposal, and a project involving removal of gas pressure
regulators from homes.

12
testified, however, that these results could not be generalized beyond the
units tested. Sheehan testified that test results from a single unit cannot be
extrapolated even to other units in a batch because it is necessary to account
for variability between units resulting from uneven distribution of chemicals
within a batch, or between batches for products. Factors influencing
variability include changes in ingredients or sources of the ingredients,
changes or inconsistency in manufacturing processes and changes in the
recipe for the product. Sheehan testified that the standard practice is to
sample individual units within a batch to “understand the conditions of the
individuals that make up that batch,” then “do the same thing in all of the
batches that are of interest within the time frame of the evaluation so that
you can say with confidence what is a condition of the population that is
made up of all of those batches of individuals within those batches.”
According to Sheehan, the literature on skin-lightening creams reflects
variability as to measurable added mercury, with some batches having no
detectable mercury and others having levels “related to added mercury.”
Asked about the CDPH investigation in which seven of 120 samples of skin-
lightening creams tested positive for significant amounts of mercury,
Sheehan testified the data suggested there would be detectable added levels
of mercury in relatively few skin creams. He disagreed with Steinberg and
Solomon because they only evaluated the individual units tested, with no
effort to “assess variability among batches or among products.” Asked if they
followed “appropriate scientific method,” Sheehan testified, “I don’t believe
they followed any method. They made some assumptions. So no, they did
not follow any sort of standard method for characterizing variability within a
product.”

13
 Sheehan stated that Steinberg’s “assumption” that “under good
manufacturing practice one would expect to find mercury in different batches,
if you found it in one batch” was not supported by the data and literature,
which contain “examples where there was mercury detected at some batches
of a lot and not in others.” In Sheehan’s view, it did not make any difference
that mercury was an added ingredient in the skin-lightening creams for the
same reason: The literature indicated that “any measurement in one
batch . . . will not tell you what is happening within the population of that
skin-lightening cream.”
Sheehan acknowledged that a study he conducted on whether users of
talcum powder in the 1960’s and 1970’s were exposed to asbestos was based
on analysis of five individual containers, each a different product. He also
acknowledged that at his deposition he did not recall having worked on a
cream applied to the body other than sunscreen, which he declined to answer
questions about, and that he had never previously been an expert in a case
involving mercury and skin-lightening cream, advised a client regarding
mercury in skin-lightening creams, done any work evaluating the presence or
absence of mercury in cosmetics, or otherwise had experience with analyzing
heavy metal exposure in creams.
Amazon’s Marketplace
As described by Christopher Poad, Director of Amazon Business
International, Amazon both sells products directly to customers through its
“Amazon Retail” business and operates a “marketplace” through which third-
party sellers sell products to customers. Approximately 2.5 million third
parties list and sell approximately 600 million unique products on the
Amazon Web site. In 2018, the total value of products sold on the Amazon

14
Web site worldwide was approximately $300 to $350 billion, 50 to 55 percent
of which ($150 to $175 billion) were sales by third parties.
Amazon provides third-party sellers with the ability to list their
product for sale, provide a title, description and image for the listing, and
have Amazon collect payment on the sellers’ behalf. Sellers can choose to
fulfill orders themselves, making their own arrangements for warehousing
and shipping, or use Amazon’s “Fulfillment by Amazon” or “FBA” service.
With FBA, the third-party seller’s products are stored in an Amazon
fulfillment center (warehouse), then shipped to the customer by Amazon
when the seller makes a sale. For third-party sales, ownership of the product
is transferred from the seller to the customer without Amazon taking title.
By contrast, for Amazon Retail, Amazon purchases the merchandise from a
supplier, owns it, and then resells it to the customer.
The products at issue in this case were all placed on the Amazon Web
site by third-party sellers, and at least one used the FBA service.
Third-party sellers are required to consent to Amazon’s “Business
Solutions Agreement,” which details matters including indemnification and
insurance requirements for sellers. Amazon charges fees to sell products on
the marketplace, which it earns when the seller completes a sale and the
product is shipped to the customer. Customers use the Amazon Web site to
complete purchases and in most transactions, there is no communication
between customers and third-party sellers; if there is, it goes through the
Amazon platform. Amazon’s Web site does not provide contact information
for third-party sellers; it offers a “contact seller” option through which a
customer can send a message, which Amazon forwards to the seller, and the
seller can respond.

15
 Each unique product on the Amazon Web site has its own product
description page. The content for this page, including product name,
description, price, and quantity available for sale, is provided by the third-
party seller. When a third party creates a new product listing, if the product
does not already exist on the Web site, it is assigned a new ASIN. Materials
for sellers “encourage and require” them not to create duplicate listings and it
is not in their interest to do so, because if there are two pages for a single
product, each will only get half as many people looking at it. Amazon has
software that scans the product catalog for products that look identical, or
“very, very similar,” and merges such products onto a single page, and the
customer service team is able to merge pages together if someone reports
duplicates. According to Poad, it is not sufficient to look at product images to
determine whether two are the same because manufacturers may change the
contents without changing packaging and many use stock images for multiple
products; instead, one must look at unique identifiers such as the Uniform
Product Code, descriptions and titles.
During the process for setting up the product description page, sellers
“have the ability to flag whether the product they are selling requires a
Proposition 65 warning for California residents,” and if they select this
option, a warning is displayed on the product description page that links to a
page in the customer help section of the Web site. In its “policies and
agreements” for sellers, Amazon provides a list of examples of “prohibited
listings” that includes “Products and ingredients that the [FDA] has
determined present an unreasonable risk of injury or illness, or are otherwise
unsafe, such as . . . [s]kin creams containing mercury.”
Amazon’s director of worldwide product compliance and safety, David
Kosnoff, testified in his deposition that the Amazon product safety team in

16
Europe reviews products listed on RAPEX notifications and these products
are removed from Amazon’s European Web sites, but not necessarily those in
other countries. If a product was listed on RAPEX in 2015, Amazon would
have searched its European Web sites and, if the product was listed, would
have taken down the listing and notified customers; the United States
marketplace would not have been impacted. A recall in one country would
not necessarily trigger recall in another because it can be difficult to
determine whether products that appear identical in different countries are
actually the same product.
Kosnoff testified Amazon would have been aware of the 2013 RAPEX
notification for Faiza Beauty Cream. He did not know whether the product
was listed on Amazon’s European Web sites. He was aware a “very similar”
product was listed on the United States Web site and did not believe any
action would have been taken to notify the United States marketplace of the
European recall. The record documents sales of Faiza Beauty Cream on the
Amazon Web site through late 2015.
Face Fresh, which was also the subject of a 2013 RAPEX notification,
was being sold on Amazon’s Web site as of January 16, 2019.
After Lee’s May 22, 2014, 60-day notice of violation, which listed
Monsepa Express Peeling Night Face Cream as an example of “[s]kin-
lightening creams,” on June 11, 2014, Amazon added a Proposition 65
warning to the listing for Monsepa Express Peeling cream (ASIN
B0030K8GJY). Between these dates, there were five sales of this product
(May 23, 29, 31, June 2, 6). Amazon removed the listing from the Web site on
August 12, 2014.

17
 DISCUSSION
We begin with the elements of the Proposition 65 claim because, as will
be seen, the nature of this claim is critical to the question of immunity under
section 230 of the CDA.
I.
The trial court found Lee did not prove that each of the 27 products
identified in the second amended complaint contained mercury because Lee
purchased and tested only one unit each of five products. 16 The court
concluded the product detail pages from Amazon’s Web site that Lee
introduced into evidence did not establish the 27 products originally
identified were the same products he tested because the pages were for only a
few products and contained “multiple material differences, including different
“product names, pictures, sellers, descriptions, ASINs and UPCs.” The court
therefore limited Lee’s claims to “the four products he purchased on Amazon
and tested.”
Moreover, the court found Lee did not prove the test results showing
mercury in one unit of a given product should be generalized to other units of
that product or similarly named ones because Lee did not introduce evidence
of “how, when, where or by whom any of the tested units were manufactured,
filled, stored, or distributed, including any lot or batch information for the
tested samples,” leaving no scientific or evidentiary basis for determining
whether other units of the same product or similar ones under the same

16 The trial court referred to Lee having tested four products purchased
from Amazon’s Web site, plus one unit of a fifth product purchased on
www.aztopsel.com. As we understand the record, the five samples Lee had
tested for this case were each from a product with a distinct ASIN, purchased
on Amazon’s Web site, although the two Meiyong products had the same
product name and the Monsepa product was shipped from aztopsel.com.

18
brand name contained mercury. The court pointed to a comment on the
laboratory report for one of the samples Lee had tested, which stated, “Please
note that these results apply only to the sample(s) submitted for this report.
Samples from a different portion of the same lot may produce different
results.” The court also observed that the RAPEX notices identified batch
numbers for the product involved. The court rejected the opinions of Lee’s
expert witnesses that the test results Lee obtained could be generalized to
untested units, finding them contradicted by the testimony of Amazon’s
expert witness and two of Lee’s own witnesses.
Lee argues the trial court’s conclusions are both legally and factually
unsupported. Preliminarily, he points out that the trial court ignored his
narrowing of the products at issue from the 27 identified by ASIN in the
second amended complaint to four products appearing under 11 ASINs on
Amazon’s Web site, and argues the trial court erred in limiting the case to
four ASINs for which laboratory tests were obtained. More fundamentally,
he argues the trial court erred in concluding test results for one unit of a
given product could not be extrapolated to other units of the same product for
purposes of determining whether Proposition 65 warnings were required.
Amazon treats these issues as purely factual, to be reviewed under the
substantial evidence test. Focusing on descriptions of this test as requiring
us to “look only to the evidence supporting the prevailing party” and “discard
evidence unfavorable to the prevailing party” (Felgenhauer v. Soni (2004)
121 Cal.App.4th 445, 449), Amazon argues the court’s conclusions were
supported by its witnesses’ testimony—Poad’s, as to each ASIN representing
a distinct product, and Sheehan’s (along with Steinberg’s and Dr. Brian
Lee’s) as to a test of one unit being insufficient to demonstrate the presence of
mercury in another unit of the same product.

19
 To the extent these issues are purely factual, Amazon is of course
correct that we review the trial court’s decision under the substantial
evidence test. “ ‘In determining whether a judgment is supported by
substantial evidence, we may not confine our consideration to isolated bits of
evidence, but must view the whole record in a light most favorable to the
judgment, resolving all evidentiary conflicts and drawing all reasonable
inferences in favor of the decision of the trial court. (People v. Johnson (1980)
26 Cal.3d 557, 576–578.) We may not substitute our view of the correct
findings for those of the trial court; rather, we must accept any reasonable
interpretation of the evidence which supports the trial court’s decision.’ ”
(DiMartino v. City of Orinda (2000) 80 Cal.App.4th 329, 336, quoting Beck
Development Co. v. Southern Pacific Transportation Co. (1996) 44
Cal.App.4th 1160, 1203–1204.) Nevertheless, we do not defer to the trial
court’s decision entirely. (DiMartino, at p. 336.) “Substantial evidence is a
deferential standard, but it is not toothless.” (In re I.C. (2018) 4 Cal.5th 869,
892.) “ ‘ “We may not uphold a finding based on inherently improbable
evidence or evidence that is irrelevant to the issues before us. [Citation.]”
[Citation.]’ (Richardson v. City and County of San Francisco Police Com.
(2013) 214 Cal.App.4th 671, 692.)” (Daugherty v. City and County of San
Francisco (2018) 24 Cal.App.5th 928, 944.)
In particular, “expert testimony does not constitute substantial
evidence when based on conclusions or assumptions not supported by
evidence in the record (Hongsathavij v. Queen of Angels etc. Medical
Center (1998) 62 Cal.App.4th 1123, 1137), or upon matters not reasonably
relied upon by other experts (Pacific Gas & Electric Co. v. Zuckerman (1987)
189 Cal.App.3d 1113, 1135). Further, an expert’s opinion testimony does not
achieve the dignity of substantial evidence where the expert bases his or her

20
conclusion on speculative, remote, or conjectural factors. (Leslie G. v. Perry &
Associates (1996) 43 Cal.App.4th 472, 487.) When the trial court accepts an
expert’s ultimate conclusion without critically considering his or her
reasoning, and it appears the conclusion was based on improper or
unwarranted matters, we must reverse the judgment for lack of substantial
evidence. (Pacific Gas & Electric Co. [at p.] 1136.) On the other hand, the
trial court is free to reject testimony of a party’s expert, so long as the trier
does not do so arbitrarily. (Howard v. Owens Corning (1999) 72 Cal.App.4th
621, 633.)” (People ex rel. Brown v. Tri-Union Seafoods, LLC (2009)
171 Cal.App.4th 1549, 1567–1568.)
We turn first to the trial court’s conclusion that a laboratory test
finding a high level of mercury in one unit of a skin-lightening cream is an
insufficient basis for concluding other units of the same product contain
mercury. All the relevant experts—Steinberg, Solomon, and Sheehan—
agreed that because of potential variability in factors such as ingredients,
supply sources, manufacturing processes, and storage conditions, multiple
samples would have to be tested to ensure consistency of a product within a
batch and across multiple batches. Such testing would be necessary, all
agreed, to determine matters such as the amount of an intentional ingredient
or presence of a contaminant.
The question in the present case, however, is whether the test results
for one unit of a product could be sufficient to determine whether mercury
was present in other units—not whether any specific amount was present,
just whether it was present at all. Lee’s experts testified that answering this
“yes/no” question did not require testing more than one unit of each product,
or considering variables such as manufacturing and packaging procedures,
because the amount of mercury in the unit tested was so high that it

21
demonstrated mercury was the intentionally added active ingredient—the
ingredient used to achieve the product’s intended purpose. Because it was
the active ingredient, while there might be variation in the actual
concentration of mercury from one unit or batch to another, there would not
be units in which mercury was completely absent. Significantly, Sheehan,
too, agreed that the levels of mercury found in the tested samples indicated it
was an intentional ingredient, not a contaminant.
In rejecting Solomon’s and Steinberg’s conclusions as to generalizing
the test results, the trial court first cited the deposition testimony of
Dr. Brian Lee, who Lee had identified as an expert witness but did not
present as a witness at trial, that “there is insufficient information to
conclude that any untested unit contains mercury.”
Dr. Lee testified at his deposition that his only assignment for this case
was to determine “how much an exposure might occur to users.” Asked
whether he would be offering an opinion that any unit of a product at issue in
the case contained mercury other than the 11 samples for which he was given
lab test results, Dr. Lee first clarified that the questioner meant “all of the
other units that are on the market,” then responded, “No. I only know what
is in these products. These may represent what’s in the other products, but
until you actually test what is in the products, there could be several
batches.”
The trial court’s summary of Dr. Lee’s deposition testimony makes it
appear more definitive than it actually was. The questioner explained he was
asking about “units” of a product, not “product,” but Dr. Lee’s response
referred to “products,” suggesting he was saying the products tested might or
might not represent other products, not necessarily that one unit of a given
product might or might not represent other units of that product (although

22
his references to “batches” creates some ambiguity). Moreover, especially in
light of his assignment to determine “how much an exposure might occur to
users,” the deposition excerpt read into the record at trial does not make clear
whether Dr. Lee understood the question as asking about absolute presence
or absence of mercury across units of a given product or about potential
variability in the amount of mercury in one unit as compared to another, or
whether he considered the significance, if any, of mercury being the active
ingredient in the creams.
Dr. Sheehan was expressly asked whether it made any difference to
him that mercury was an intentionally added ingredient and testified that it
did not. His response, while not entirely clear, appears to concern variability
among batches without explaining how variability would extend to complete
absence of the product’s active ingredient. 17 The trial court summarized
Dr. Sheehan’s testimony as stating that “there is variation in the mercury
content of skin-lightening creams, even when one expects to find mercury,
and that a scientific method is needed to generalize from one unit to other
units and other batches.” But as far as we are aware, Dr. Sheehan did not
explain why this is so in the case of a product intended to address cosmetic
issues for which mercury is an effective treatment and demonstrated—albeit
in one or a small number of samples—to contain such high levels of mercury
that it must be an intentional ingredient.

17 Dr. Sheehan responded, “For the same general reason that I gave for
the other, that is if you look at the literature, is if you find in one batch no
skin-lightening creams and in another batch, you find some measurable
added level of skin-lightening creams, it suggests that any measurement in
one batch. It will not tell you what is happening within the population of
that skin-lightening cream.”

23
 The portions of Steinberg’s testimony that the trial court saw as
contradicting his own and Solomon’s testimony that the test results could be
generalized to the product line from which the sample was taken are not, in
fact contradictory. The court noted Steinberg’s testimony that “at least three
or four tests per batch would be needed to ensure uniformity of a cosmetic
product,” that in order to predict consistency across units and batches, it is
necessary to know whether a product was manufactured according to current
cGMPs, and that, in effect, he did not expect cGMPs were followed for the
products at issue. This testimony, however, addressed uniformity and
consistency of the product. Steinberg expressly distinguished the testing
necessary to ensure uniformity and consistency from that necessary to
determine whether mercury is present in units of a specific skin-whitening
product other than the unit tested where mercury is known to be the active
ingredient in skin-whitening products because of its effectiveness in
lightening skin, is the single ingredient known to also treat acne, as
advertised for some of the creams at issue, and is found in high
concentrations in one or a few samples of that specific skin-lightening
product.
Amazon’s statement that this is “a rare case where all experts on both
sides agreed that it was not possible to extrapolate test results from a single
unit of four products to all other units of that product line” is thus divorced
from the record. This was Dr. Sheehan’s testimony, but not Dr. Solomon’s or
Steinberg’s; Lee’s witnesses both testified that in the circumstances here, the
tests could be generalized to other units of the product line from which the
tested sample was taken.
The trial court also noted that the National Food Lab’s report for the
samples of Monsepa creams tested for the California Department of Justice

24
in 2013 contained the comment, “Please note that these results apply only to
the sample(s) submitted for this report. Samples from a different portion of
the same lot may produce different results.” This comment, again, refers to
the undisputed potential for variability in uniformity and consistency across
lots. It does not address the disputed question whether test results finding a
high level of the active ingredient in a single sample can be generalized to
conclude all samples of that product will have some amount of the active
ingredient.
Finally, the trial court noted that the RAPEX notices “delineate batch
numbers of any product involved within the notice(s).” The observation is
only partially accurate. The RAPEX notice for Face Fresh Beauty Cream
provided information in the spaces for “Type/number of model” and “Batch
number/Barcode,” 18 but the RAPEX notice for Faiza No. 1 Beauty Cream, in
these spaces, stated “Unknown.” Moreover, the warning issued and report of
action taken for both RAPEX notices pertained to “the product,” unlimited by
batch number or otherwise. Both notices, for “Risk description,” stated that
“[t]he product poses a chemical risk because it contains mercury” and “[t]he
product does not comply with the Cosmetics directive 76/768/EEC.” Both
notices reported the “[m]easures adopted by notifying country” as “Voluntary
measures: Withdrawal of the product from the market.”
In sum, the trial court’s stated reasons for concluding that a laboratory
test finding a high level of mercury in one unit of a skin-lightening cream is
an insufficient basis for inferring other units of the same product contain
mercury do not withstand scrutiny. The only evidence directly supporting

18The RAPEX notice for Face Fresh Beauty Cream, for “Type/number
of model,” stated, “Unknown Batch number: No 1192 - MFG 1 3 12 EXP 1 3
14” and for “Batch number/Barcode” stated, “1 41960 001908.”

25
the trial court’s conclusion, Dr. Sheehan’s testimony, failed to explain the
basis for his rejection of the other experts’ distinction between testing to
determine uniformity and consistency of a product and testing to confirm the
absolute presence or absence of the active ingredient in a product. Indeed,
Dr. Sheehan’s testimony on this point was inconsistent with the design of his
own investigation of asbestos in talcum powder. Dr. Sheehan acknowledged
that a study he conducted on whether users of talcum powder in the 1960’s
and 1970’s were exposed to asbestos reported on the health risk from using
talcum powder during that period based on analysis of five individual
containers, each a different product. These five samples of five different
products were the basis for what appears to be a broad conclusion in an
article published in the peer-reviewed scientific literature that “[t]he absence
of detectable asbestos fibers confirms the previous findings that most
historical cosmetic talcum powder products did not produce asbestos fiber
exposures.” Additionally, while Solomon and Steinberg both had
considerable experience with the specific subject of testing here—mercury in
skin-lightening creams—Sheehan did not recall having worked on a cream
applied to the body other than sunscreen and had no experience with
mercury in cosmetics or heavy metals in creams.
Dr. Sheehan’s testimony is also difficult to reconcile with the practice of
governmental entities responsible for regulating harmful consumer products.
A CDPH employee who helped write the January 2014 news release warning
against use of certain skin-lightening creams testified that the sample of
Monsepa Express Peeling cream that was the basis for the alert did not have
batch or lot numbers or other such identifying information and the alert was
issued “for any and all products that have this appearance in name.”
Dr. Solomon testified that “it’s something regulatory agencies not

26
infrequently will do based on a single sample or very few samples.” This
makes obvious sense where the issue is whether a product contains the
chemical in question at all, and not the precise amount in any individual
unit.
Proposition 65 imposes a duty to warn based on presence of a listed
chemical in a product, without requiring uniformity across individual units in
the precise amount of the chemical in a given unit. When the chemical at
issue is the product’s active ingredient, its complete absence in an individual
unit would be fortuitous. “Proposition 65 is a ‘right to know’ statute
requiring companies that expose consumers to carcinogens or reproductive
toxins to provide a reasonable and clear warning. (Health & Saf. Code,
§ 25249.6.) It is a remedial law, designed to protect the public, and thus we
construe its provisions broadly to accomplish that protective purpose. (People
ex rel. Lungren v. Superior Court (1996) 14 Cal.4th 294, 314.)” (Center for
Self-Improvement & Community Development v. Lennar Corp. (2009)
173 Cal.App.4th 1543, 1550–1551.) Once it is confirmed that a product
contains a high level of a chemical listed as a toxin under Proposition 65 as
an intentional ingredient (not as a contaminant), it would be inconsistent
with the statutory purpose to require the kind of testing necessary to ensure
product uniformity or consistency before enforcing the duty to warn.
Amazon’s assertion that there was no evidence mercury was an
intentional ingredient in these products is without basis in the record and
directly inconsistent with even its own expert’s testimony: Sheehan fully
agreed that mercury was present in the samples tested in amounts
demonstrating it was an ingredient, not a contaminant. Amazon points to
the CDPH testing that found most skin-lightening creams on the California
market did not contain mercury, but that does not refute the undisputed

27
evidence that the products at issue here tested positive for mercury, at very
high levels.
Given the undisputed evidence that samples of five skin-lightening
products purchased on Amazon’s Web site contained high levels of mercury as
an intentionally added ingredient, there is no basis for a conclusion that Lee
failed to prove this element of his case with respect to these products, at a
minimum. If Lee proved the other elements of his claim, it cannot be
rejected—at least for these specific products—on the ground that he failed to
prove the products contained mercury.
Beyond the products tested, a question remains. The trial court
concluded Lee did not prove each of the 27 products listed by ASIN in the
second amended complaint contained mercury because the evidence did not
establish that they were the same products as the ones 19 tested. Lee
subsequently limited his claims to 11 products that he claimed were the same
as those tested despite having been assigned different ASINs. Given our
rejection of the trial court’s conclusion that Lee failed to prove the tested
products contained mercury, if the remaining elements of his claims were
also established as to these specific products, the trial court will have to
determine whether the untested products within the identified group of 11
were in fact the same products as the ones tested.
II.
As earlier stated, Proposition 65 provides that “[n]o person in the
course of doing business shall knowingly and intentionally expose any

19The trial court referred to four products having been tested for this
case. As earlier indicated, five samples were tested, one each for the Faiza,
Monsepa, and Face Fresh creams, and two for Meiyong skin-lightening
creams with the same name but assigned different ASINs on Amazon’s Web
site.

28
individual to a chemical known to the state to cause cancer or reproductive
toxicity without first giving clear and reasonable warning to such individual,
except as provided in Section 25249.10.” (Health & Saf. Code, § 25249.6,
italics added.) Lee argues the trial court erred in requiring him to prove
Amazon had actual knowledge that the products at issue contained mercury,
maintaining that constructive knowledge is sufficient to trigger the duty to
provide Proposition 65 warnings. In general, “[p]roof of actual knowledge
focuses on what information a defendant must have been aware of, while
proof of constructive knowledge rests on a defendant’s duty to discover
information.” (People v. ConAgra Grocery Products Co. (2017) 17 Cal.App.5th
51, 84–85.) “Constructive knowledge” means “[k]nowledge that one using
reasonable care or diligence should have, and therefore that is attributed by
law to a given person.” (Black’s Law Dict. (11th ed. 2019) p. 1043, col. 1;
Castillo v. Toll Bros., Inc. (2011) 197 Cal.App.4th 1172, 1197.)
Proposition 65 does not define the term “knowingly.” (See Health &
Saf. Code, § 25249.11 [“Definitions”].) The regulations define the term as
follows: “ ‘Knowingly’ refers only to knowledge of the fact that a discharge of,
release of, or exposure to a chemical listed pursuant to Section 25249.8(a) of
the Act is occurring. No knowledge that the discharge, release or exposure is
unlawful is required. However, a person in the course of doing business who,
through misfortune or accident and without evil design, intention or
negligence, commits an act or omits to do something which results in a
discharge, release or exposure has not violated [Health and Safety Code]
Section 25249.5 or 25249.6 of the Act.” (Regs., §§ 25102, subd. (n), 25600.1,
subd. (h).) Neither Proposition 65 nor the regulations use the phrase
“constructive knowledge” or language commonly associated with the concept,

29
such as “should know” or “reason to know.” Nor do Proposition 65 or the
regulations applicable to this case use the phrase “actual knowledge.” 20
The trial court provided little explanation of its determination that
Proposition 65 requires proof of actual knowledge. In granting Amazon’s
motion in limine to exclude evidence of constructive knowledge, the court
cited the “statute itself” and “the nature of the Prop 65 process including the
notice aspects.” In its statement of decision, the court stated, “Proposition 65
and its terms apply only to ‘businesses that know they are putting one of the
chemicals into the environment.’ (See Nicolle-Wagner v. Deukmejian (1991)
230 Cal.App.3d 652, 659 [quoting with approval language from ballot
argument in favor of Proposition 65].)”
Nicolle-Wagner v. Deukmejian, supra, 230 Cal.App.3d 652 (Nicolle-
Wagner) was not concerned with the nature of the knowledge requirement in
Proposition 65 and does not discuss any distinction between actual and
constructive knowledge. The question in that case was whether Proposition
65 was intended to apply to naturally occurring carcinogens and reproductive
toxins in food. Holding it was not, the court described the statutory language
and ballot arguments for and against Proposition 65 as indicating the
measure “sought to regulate toxic substances which are deliberately added or
put into the environment by human activity. . . . [¶] . . . . [T]he ballot
argument in favor of Proposition 65 explains that ‘[Proposition 65] will not
take anyone by surprise. [It] applies only to businesses that know they are
putting one of the chemicals out into the environment . . . .’ (Italics in
original.)” (Nicolle-Wagner, at p. 659.) While the emphasis on “know,” in

20 As will be further discussed, a regulation adopted subsequent to the
sales of the products at issue in this case refers to “actual knowledge” in
limiting the situations in which retail sellers are required to provide
warnings. (Regs., § 25600.2, subd. (e).)

30
context, might naturally be understood by a layperson as implying actual
knowledge, in legal terms “ ‘knowledge’ encompasses both actual knowledge
and constructive knowledge.” (Tsasu LLC v. U.S. Bank Trust, N.A. (2021)
62 Cal.App.5th 704, 718 (Tsasu).) 21
Lee relies heavily on a 1988 agency interpretation of the statutory
“knowingly and intentionally” language as including constructive
knowledge. 22 “An administrative agency has the power to adopt regulations
to effectuate the statutory purpose, provided the regulations are not in
conflict with applicable statutes. (Woods v. Superior Court (1981) 28 Cal.3d

21 The Tsasu court was called upon to determine whether the term
“knowledge” in a provision of the Quiet Title Act meant solely actual
knowledge or included constructive knowledge as well. Its first reason for
adopting the later interpretation was that inclusion of constructive
knowledge was “the result dictated by the statute’s plain language.
([Citation]. [Civ. Code,] § 764.060 uses the term ‘knowledge,’ and ‘knowledge’
encompasses both actual knowledge and constructive knowledge.
[Citations].)” (Tsasu, supra, 62 Cal.App.5th at p. 718.)
22 Lee also relies on the provisions in the regulation defining
“knowingly” that “[n]o knowledge that the discharge, release or exposure is
unlawful is required” and “a person in the course of doing business who,
through misfortune or accident and without evil design, intention or
negligence, commits an act or omits to do something which results in a
discharge, release or exposure has not violated [Health and Safety Code]
Section 25249.5 or 25249.6 of the Act.” (Regs., §§ 25102, subd. (n), 25600.1,
subd. (h).) Lee observes that this regulation “contemplates that ‘negligence’
is actionable,” but does not further explain how the definition bears on the
question of actual versus constructive knowledge. The inference that
constructive knowledge is sufficient if negligence is actionable makes obvious
sense where the negligence is with respect to awareness of the presence of a
listed chemical in a product (i.e., if the defendant, in the circumstances,
should have known the chemical was present and remained ignorant due to
negligence, a warning would be required). The inference seems less clear,
however, if the negligence is in regard to exposure (e.g., selling the product).
In any event, we do not see this point as critical to our analysis.

31
668, 679; Nicolle–Wagner, supra, 230 Cal.App.3d [at p.] 658.) We defer to the
technical skill and expertise of the administrative agency in interpreting the
statutes. (Ibid.)” (Mission Community Hospital v. Kizer (1993) 13
Cal.App.4th 1683, 1691.)
The agency initially responsible for implementing Proposition 65, 23 in
its November 1988 Revised Final Statement of Reasons for what was then
section 12601 of title 22 (now tit. 27, § 25601) of the California Code of
Regulations, interpreted the Proposition 65 requirement that exposures be
“knowing and intentional” before a warning is required “to include exposures
about which there is constructive knowledge.” (OEHHA, Revised Final
Statement of Reasons, 22 California Code of Regulations, Division 2 (Nov.
1988), p. 39 (1988 FSOR).)
Amazon points out that this section of the 1988 FSOR was discussing
environmental exposures, which are distinct from consumer product
exposures. But the agency’s statement about constructive knowledge was not
limited to environmental exposures. While it happened to be made in a
section discussing environmental exposures, as it was responding to a
comment about the definition of such exposures, the “knowing and
intentional” language applies to all exposures, not just environmental ones. 24

23 The Governor originally designated the Health and Welfare Agency
as the “lead agency” for Proposition 65, with authority to “adopt and modify
regulations, standards, and permits, as necessary, in order to conform with
and implement the purposes of the initiative statute.” (Nicolle-Wagner,
supra, 230 Cal.App.3d at p. 655.) The California Environmental Protection
Agency’s Office of Environmental Health Hazard Assessment (OEHHA) was
designated the lead agency for implementation of Proposition 65 in 1995.
(Regs., § 25102, subd. (o); Health & Saf. Code, § 25249.12, subd. (a).)
At the time, the regulation defined “ ‘environmental exposures’ as
24

those which may foreseeably occur as the result of contact with an
environmental medium . . . .” (1988 FSOR, supra, p. 39.) In response to a

32
Other portions of the 1988 FSOR also discuss constructive knowledge, thus
making clear that the agency interpretation was not limited as Amazon
suggests. 25

concern that “requiring exposures to be foreseeable detracts from the
requirement that exposures be knowing and intentional before a warning is
required,” the agency explained that it interpreted the “knowing and
intentional” requirement to include constructive knowledge and its “[u]se of
the term ‘foreseeable’ is intended to define the limits of that constructive
knowledge and of exposures for which businesses can reasonably be held
responsible.” (Id. at pp. 39–40.) The current regulations do not include the
terms “foreseeable” or “foreseeably” in the definition of “environmental
exposure,” providing simply that such exposure means “an exposure that
occurs as the result of contact with an environmental source . . . .” (Regs.,
§ 25600.1, subd. (f).) The definition of “consumer product exposure” included
“reasonably foreseeable use of a consumer good,” and still does. (1988 FSOR,
p. 8; Regs., § 25600.1, subd. (e).)
25 Regarding the statutory phrase “discharge or release into water or
onto or into land” in Health and Safety Code section 25249.5, the agency had
proposed a regulation regarding liability when a person in the course of doing
business transfers a chemical to a person authorized to receive it, which a
commentor viewed as an attempt to impose vicarious liability on a transferor
who has no control over the transferee. (OEHHA, Final Statement of
Reasons, 22 California Code of Regulations, Division 2, Safe Drinking Water
and Toxic Enforcement Act of 1983 (R-48-87) § 12101 et seq. (Jan. 1988) p. 26
[as of
Mar. 11, 2022]; see Regs., § 25102, subd. (f).) The agency modified the
proposed regulation to provide that “discharge or release” to a source of
drinking water includes transfer “for the principal purpose of disposing of the
chemical to land or water in a manner which, if committed by the transferor
would violate § 25249.5” and explained: “This proposal does not impose
vicarious liability for acts over which the transferor has no control. In fact,
this provision envisions that the transferor knows or reasonably should know
that the transferee will make an otherwise prohibited discharge, and can
control that behavior simply by not making the transfer. Further, this
provision does not conflict with the requirement that discharges or releases
prohibited under the Act be committed ‘knowingly.’ The transferor would
still have actual or constructive knowledge of the discharge of the listed
chemical.” (1988 FSOR, p. 27; see Regs., § 25102, subd. (f), italics added.)

33
 Amazon does not expressly argue the agency has disavowed the general
interpretation of “knowingly and intentionally” as including constructive
knowledge. Instead, it points to a regulation adopted by OEHHA in 2016
which it says “clarif[ies] that ‘knowledge’ for downstream entities means
actual knowledge.” As relevant here, Regulations section 25600.2,
subdivision (e) provides: “The retail seller is responsible for providing the
warning required by Section 25249.6 of the Act for a consumer product
exposure only when . . . [¶] . . . [¶] [t]he retail seller has actual knowledge of
the potential consumer product exposure requiring the warning, and there is
no manufacturer, producer, packager, importer, supplier, or distributor of the
product who: [¶] . . . [i]s a ‘person in the course of doing business’ under
Section 25249.11(b) of the Act, and [¶] . . . [h]as designated an agent for
service of process in California, or has a place of business in California.”
(Regs., § 25600.2, subd. (e)(5), italics added.) “Actual knowledge,” for
purposes of this regulation, means “the retail seller receives information from
any reliable source that allows it to identify the specific product or products
that cause the consumer product exposure. Such knowledge must be received
by the retail seller, its authorized agent or a person whose knowledge can be
imputed to the retail seller. (Regs., § 25600.2, subd. (f)(1).) Further, “[w]here
the source of a retail seller’s knowledge is a notice pursuant to Section
25249.7(d)(1) of the Act, the retail seller shall not be deemed to have actual
knowledge of any consumer product exposure alleged in the notice until five
business days after the retail seller receives the notice. The notice must
provide sufficient specificity for the retail seller to readily identify the
product or products subject to the notice, in accordance with Article 9, section
25903(b)(2)(D).” (Regs., § 25600.2, subd. (f)(2).)

34
 These regulations were adopted in furtherance of the statutory
directive in Health and Safety Code section 25249.11, subdivision (f), that
“[i]n order to minimize the burden on retail sellers of consumer products
including foods, regulations implementing Section 25249.6 shall to the extent
practicable place the obligation to provide any warning materials such as
labels on the producer or packager rather than on the retail seller, except
where the retail seller itself is responsible for introducing a chemical known
to the state to cause cancer or reproductive toxicity into the consumer product
in question.” (OEHHA, Final Statement of Reasons, Title 27, California Code
of Regulations, Proposed Repeal of Article 6 and Adoption of New Article 6,
Regulations for Clear and Reasonable Warnings (2016) p. 35 (2016 FSOR).)
The agency stated, “By adopting these new regulations, OEHHA
intends to address many of the issues that have surfaced since the original
regulations were adopted in 1988 by clarifying the relative responsibilities of
manufacturers and others in the chain of distribution for products that are
eventually sold at retail . . . .” (2016 FSOR, supra, p. 9.) As to retail sellers,
the agency explained, Regulations “Section 25600.2 is based on the premises
that (1) the consumer must receive the warnings mandated by [Health and
Safety Code] Section 25249.6 of the Act before being exposed to a chemical
known to cause cancer or reproductive toxicity; and (2) the primary
responsibility for providing the warning for products, including foods, is with
the manufacturer, producer, packager, importer, or distributor of those
products. The regulations therefore recognize that those parties are
primarily responsible for providing warnings. This is reasonable, as
manufacturers usually will have greater knowledge than retailers of a
product’s chemical content and whether it causes chemical exposures that
require a warning.” (2016 FSOR, p. 35.)

35
 Amazon, in the trial court, argued it was not a retail seller, and Lee
therefore maintains Amazon forfeited any claim to the contrary and cannot
rely upon the actual knowledge requirement pertaining to retail sellers.
Amazon continues to argue it was not part of the chain of distribution at all
and consequently was not responsible for providing Proposition 65 warnings,
but adds that “[a]ssuming arguendo that Amazon is subject to this duty, the
only classification that could apply is the end of the chain—i.e., the ‘retail
seller.’ ”
The trial court found it unnecessary to determine whether Amazon is a
retail seller or whether Regulations section 25600.2, subdivision (e), applies
retroactively to this case (as the product sales at issue preceded the 2016
amendments) because of the broad definition of parties required to provide
Proposition 65 warnings (“person in the course of doing business”) and the
fact Amazon did not claim to be a “retail seller” without responsibility for
warnings pursuant to the 2016 regulation (Regs., § 25600.2, subd. (e)). Yet
the court relied on the definition of “actual knowledge” in this regulation in
finding Lee failed to establish Amazon had actual knowledge that the
products contained mercury.
The trial court was clearly correct to reject Amazon’s claim to be
outside the chain of distribution. Proposition 65 imposes the duty to provide
warnings on any “person in the course of doing business,” which
unquestionably includes Amazon’s activities here. As the trial court
explained, “there is no language in section 25249.l l(f) [‘definitions’ for
Proposition 65] or the new regulations expressly limiting the duty to provide
a Proposition 65 warning only to a ‘manufacturer, producer, packager,
importer, supplier, or distributor of a product,’ or a ‘retail seller’ (under more
limited circumstances described in C.C.R. § 25600.2(e)), or limiting the broad

36
language in the operative statute imposing the warning requirement on any
‘person in the course of doing business’ who ‘knowingly and intentionally
expose[s] any individual’ to a listed chemical. (Health & Saf. Code § 25249.6.)
The phrase ‘person in the course of doing business’ is broadly worded and not
limited to parties in the chain of distribution of a product or whose status is
defined in the regulations. (See Health & Saf. Code, § 25249.11(b).)” Amazon
manages and oversees all aspects of third-party sales on its Web site,
including accepting payment and providing refunds to customers on sellers’
behalf, providing the only channel for communication between customers and
sellers, earning fees from sellers for each completed sale and, for sellers
utilizing the FBA program, storing the products and arranging for their
delivery to customers. There can be no question Amazon was, in the words of
one court, “pivotal in bringing the product here to the consumer.” (Bolger v.
Amazon.com (2020) 53 Cal.App.5th 431, 438 (Bolger).)
This leaves two questions regarding Amazon’s reliance on Regulations
section 25600.2, subdivision (e): Does the regulation even apply to this case,
in which the salient events preceded adoption of the regulation? And, if so, is
Amazon a “retail seller” within the meaning of the regulation?
The 2016 regulations became operative on August 30, 2018
( [as of Mar. 11, 2022]). Although the product sales at
issue in this case predated even the date the regulations were adopted, much
less their operative date, Amazon argues the regulations apply retroactively
because they simply clarified existing law. Western Security Bank v. Superior
Court (1997) 15 Cal.4th 232 (Western Security), the authority Amazon relies
upon, explains that while “statutes do not operate retrospectively unless the
Legislature plainly intended them to do so,” “a statute that merely clarifies,

37
rather than changes, existing law does not operate retrospectively even if
applied to transactions predating its enactment.” (Id. at p. 243.)
Western Security involved a conflict between the antideficiency statute
prohibiting judgments for any loan balance remaining after a lender’s
nonjudicial foreclosure and the rule that the obligation of the issuer of a
letter of credit is independent of any underlying contract between the issuer’s
customer and the letter’s beneficiary. After a Court of Appeal ruled that the
issuer of a letter of credit could decline to honor it after notice it would be
used to satisfy a deficiency after a nonjudicial foreclosure sale, the
Legislature adopted a bill expressly intended to abrogate the Court of Appeal
decision and confirm the beneficiary’s right to rely upon both the real estate
collateral and the letter of credit. Western Security held the new legislation
had “no impermissible retroactive consequences” because the Legislature
made clear it was “a clarification of the state of the law before the Court of
Appeal’s decision,” intended to “apply to all existing loans secured by real
property and supported by outstanding letters of credit.” (Western Security,
supra, 15 Cal.4th at pp. 237–238.)
The “clarification” provided by Regulations section 25600.2, subdivision
(e), is entirely different. As we have said, the regulation was adopted as a
means of implementing the Legislature’s directive that the agency adopt
regulations minimizing the “burden on retail sellers of consumer products” by
“to the extent practicable plac[ing] the obligation to provide any warning
materials such as labels on the producer or packager rather than on the retail
seller,” except as specified. (Health & Saf. Code, § 25249.11, subd. (f); 2016
FSOR, supra, p. 35.) Prior regulations had not addressed the allocation of
responsibility. OEHHA described Regulations section 25600.2 as “a new,
mandatory regulation addressing the relative responsibility of product

38
manufacturers and others in the chain of distribution, versus the product
retail seller.” (2016 FSOR, pp. 8–9.) The specific requirements of this new
regulation “clarified” these relative responsibilities in the sense that they had
not previously been spelled out, not as an expression of what had always been
required. Given the high level of detail in the regulation—from delineation of
the specific circumstances in which a retail seller is responsible for providing
warnings to the definition of, and parameters for attributing, actual
knowledge—it is impossible to view the regulation as merely clarifying the
law that previously existed.
Moreover, OEHHA chose to make the 2016 regulations operative two
years after they were adopted. (Gov. Code, § 11343.4, subd. (b)(2).) 26 This
two-year period is expressly addressed in regulations concerning “ ‘safe
harbor’ ” warnings (warnings that comply with content and method of
transmission requirements “that have been determined ‘clear and reasonable’
by the lead agency”). (Regs., § 25600, subds. (a) & (b).) Subdivision (b) of
section 25600 of the Regulations provides that a warning for a consumer
product manufactured prior to August 30, 2018, is “deemed to be clear and
reasonable if it complies with” the prior regulation. The 2016 FSOR
explained that the two-year implemental period was intended to “avoid the
difficulties and expense involved for manufacturers and retail sellers to locate
all products bearing the old warnings.” (2016 FSOR, supra, pp. 13–14.) The
delayed effective date applied to all the 2016 regulations, and is clearly

26With specified exceptions, a regulation required to be filed with the
Secretary of State becomes effective on the quarterly basis established in
Government Code section 11343.4, subdivision (a). One of the exceptions is
where “[a] later date is prescribed by the state agency in a written
instrument filed with, or as part of, the regulation . . . .” (Gov. Code,
§ 11343.4, subd. (b)(2).)

39
inconsistent with any intent that the new regulations be applied
retrospectively.
Amazon, therefore, cannot rely on Regulations section 25600.2,
subdivision (e), to support the trial court’s determination that Lee was
required to prove actual knowledge.
Nor does Regulations section 25600.2 indicate Proposition 65, in
general, contains an actual knowledge requirement. In fact, the introduction
of an express “actual knowledge” requirement for retail sellers in the 2016
regulation is itself an indication that actual knowledge was not previously
required to trigger the obligation to provide Proposition 65 warnings. By
specifying that retail sellers are responsible for providing warnings only if
they have actual knowledge of the potential consumer exposure (and no
upstream entity can readily be compelled to provide the warning),
Regulations section 25600.2, subdivision (e)(5), implicitly indicates there are
circumstances in which constructive knowledge is sufficient to require
provision of a warning. It is a familiar rule of statutory interpretation that
“[a] construction making some words surplusage is to be avoided.” (Dyna-
Med, Inc. v. Fair Employment & Housing Com. (1987) 43 Cal.3d 1379, 1387.)
The same rules of construction apply to initiative measures. (Williams v.
Superior Court (2001) 92 Cal.App.4th 612, 622.) If OEHHD viewed all
references to knowledge in the Proposition 65 regulations as meaning actual
knowledge, it would not have needed to include an express “actual”
knowledge requirement in Regulations section 25600.2, subdivision (e). The
purpose of this regulation was to distinguish retail sellers’ obligations from
those of entities higher on the chain of distribution. One of the ways it does
so is by requiring “actual knowledge” where the statutory phrase “knowingly”

40
would otherwise connote—and had been interpreted as including—actual or
constructive knowledge.
The critical question, of course, is whether the electorate intended
“knowingly and intentionally” to mean solely actual knowledge or
constructive knowledge as well. As we have said, because Proposition 65 is “a
remedial law, designed to protect the public,” we construe its provisions
“broadly to accomplish that protective purpose.” (People ex rel. Lungren v.
Superior Court, supra, 14 Cal.4th at p. 314; Center for Self-Improvement &
Community Development v. Lennar Corp., supra, 173 Cal.App.4th at
pp. 1550–1551.)
The preamble to Proposition 65, section 1 of the law proposed to the
voters, makes clear the measure was driven by the voters’ desire for greater
protection against hazardous chemicals, specifically including information
about exposures, strict enforcement and deterrence of actions threatening
public health and safety. The preamble states: “The people of California find
that hazardous chemicals pose a serious potential threat to their health and
well-being, that state government agencies have failed to provide them with
adequate protection, and that these failures have been serious enough to lead
to investigations by federal agencies of the administration of California’s
toxic protection programs. The people therefore declare their rights: [¶] (a)
To protect themselves and the water they drink against chemicals that cause
cancer, birth defects, or other reproductive harm. [¶] (b) To be informed
about exposures to chemicals that cause cancer, birth defects, or other
reproductive harm. [¶] (c) To secure strict enforcement of the laws controlling
hazardous chemicals and deter actions that threaten public health and safety.
[¶] (d) To shift the cost of hazardous waste cleanups more onto offenders and
less onto law-abiding taxpayers. [¶] The people hereby enact the provisions

41
of this initiative in furtherance of these rights.” (Ballot Pamp., Gen. Elec.
(Nov. 4, 1986) text of Proposition 65, p. 53, italics added.) (Hereafter Ballot
Pamp.)
The public policy reflected in these findings and stated purposes
militates in favor of an interpretation of the “knowingly and intentionally”
requirement of Health and Safety Code section 25249.6 as including
constructive knowledge. (See Tsasu, supra, 62 Cal.App.5th at p. 719
[“defining ‘knowledge’ in [quiet title statute] to encompass both actual and
constructive knowledge is the result dictated by public policy”].) Interpreting
section 25249.6 to require warnings only when a person in the course of doing
business has actual knowledge that he or she will expose any individual to a
listed chemical would significantly limit the reach of the statute and create
incentives to avoid information that might reveal potential sources of
exposure.
Tsasu offers an illustration, albeit in a different context. Pursuant to
the statute at issue in that case, a third party acting in reliance on a quiet
title judgment retains its property rights, even if that judgment is
subsequently invalidated as void, if the third party “qualifies as a ‘purchaser
or encumbrancer for value . . . without knowledge of any defects or
irregularities in [the earlier quiet title] judgment or the proceedings.’ ([Code
Civ. Proc.,] § 764.060.)” (Tsasu, supra, 62 Cal.App.5th at pp. 716–717.)
Among its reasons for construing “knowledge” in the statute as including
both actual and constructive knowledge, the Tsasu court explained that
limiting “knowledge” to actual knowledge “creates wholly perverse incentives
because it discourages prospective buyers from checking the record of title or
from heeding ‘warning signs’ necessitating further inquiry—lest they acquire
actual knowledge of a defect or irregularity with a quiet title judgment that

42
would strip them of section 764.060’s protection. Such incentives are inimical
to the entire system of real property law in California, which places upon real
estate buyers a duty to inquire into the validity of their prospective
ownership claim [citation], and to heed—not ignore—any ‘ “reasonable
warning signs” ’ [citations].” (Id. at pp. 719–720.) The court declined to
interpret the statute as limited to actual knowledge, in part, because the
statute was not intended to “encourage recklessness or willful ignorance.”
(Id. at p. 720.)
In the context of Proposition 65, limiting the obligation to provide
warnings to actual knowledge would create incentives for businesses to avoid
information that might alert them to the presence of hazardous chemicals
and potential for exposures. This result would be inimical to the protective
purpose of the law generally, and specifically to the voters’ stated purposes of
furthering the dissemination of information about exposures to toxic
chemicals, strict enforcement of laws controlling hazardous chemicals and
deterrence of actions that threaten public health and safety. (Ballot Pamp.,
supra, p. 53.)
Amazon argues the trial court’s interpretation of Health and Safety
Code section 25249.6 as requiring actual knowledge is supported by cases
“confirm[ing] that a duty to disclose a fact cannot arise without actual
knowledge of the fact.” The cases it relies upon, however, are not particularly
helpful. In San Diego Hospice v. County of San Diego (1995) 31 Cal.App.4th
1048, the plaintiff sought recission of a release on a theory of fraudulent
nondisclosure of facts the defendant of which the defendant allegedly had
imputed knowledge. (Id. at p. 1055.) The court explained that in order to
establish the duty to disclose underlying the claim, the plaintiff must show
“the material fact is known to (or accessible only to) the defendant” and “the

43
defendant knows the plaintiff is unaware of the fact and cannot reasonably
discover the undisclosed fact.” (Ibid.) Because the duty to disclose “requires
some element of scienter—knowledge of the other party’s ignorance,” it could
not arise if the material facts were not “actually known” to the defendant:
“We cannot perceive how it is possible for a principal to know the other party
is ignorant of something of which the principal is equally ignorant.” (Id. at
pp. 1055–1056.) This reasoning, specific to the scienter element of the tort
claim at issue, has no bearing on the meaning of the knowledge requirement
in a statute requiring warnings of potential exposures to hazardous
chemicals.
The other case Amazon cites is no more apt. Santiago v. Firestone Tire
& Rubber Co. (1990) 224 Cal.App.3d 1318 involved employees’ claims under
Labor Code section 3602, subdivision (b), which provides an exception to the
general rule that workers’ compensation is the sole and exclusive remedy for
injured workers, permitting an action for damages against the employer
where the employee’s injury is aggravated by the employer’s “ ‘fraudulent
concealment of the existence of the injury and its connection with the
employment.’ ” (Santiago. at p. 1323.) Santiago held the employees were
required to show the employer had actual knowledge of the employees’
injuries and fact they were caused by their employment, rejecting the
argument that constructive knowledge should apply based on a detailed
analysis of the “history of Labor Code section 3602, the language of the
statute, and the cases construing it.” (Id. at pp. 1331–1334.) Amazon quotes
the Santiago court’s statement that “ ‘defendant obviously could not be
charged with concealing matters which it did not know.’ ” (Id. at p. 1334.)
But the issue in the present case is not concealment of facts, and the holding
that fraudulent concealment necessarily requires actual knowledge says

44
nothing about the statutory meaning of “knowingly” with respect to the
obligation to provide warnings of potential exposures under Proposition 65.
There is nothing rationally or logically inconsistent with a requirement that a
business provide warnings—or be liable for failure to do so—if it knows or
has sufficient reason to know it is exposing “any individual” to a listed toxic
chemical.
Amazon finds support for its argument that Health and Safety Code
section 25249.6 requires actual knowledge in the fact that this provision uses
the phrase “knowingly and intentionally” while section 25249.5, which
prohibits discharge of chemicals into water, uses only “knowingly.” Relying
on the rules of statutory interpretation that instruct us to, if possible, give
significance to every word and avoid a construction that renders some words
surplusage (Moyer v. Workmen’s Comp. Appeals Bd. (1973) 10 Cal.3d 222,
230), Amazon argues we cannot ignore the inclusion of “intentionally” in
Health and Safety Code section 25249.6. With this much, we agree. But we
do not agree with Amazon’s conclusion that the phrase “knowingly and
intentionally” “imposes a higher level of knowledge” than the word
“knowingly” alone.
As we have said, neither Proposition 65 nor the regulations define
“intentionally.” “ ‘ “When a term goes undefined in a statute, we give the
term its ordinary meaning.’ ” (De Vries v. Regents of University of California
(2016) 6 Cal.App.5th 574, 590–591.) ‘In divining a term’s “ordinary
meaning,” courts regularly turn to general and legal dictionaries.’ (Id. at
p. 591; People v. Hodges (1999) 70 Cal.App.4th 1348, 1355.)” (Upshaw v.
Superior Court (2018) 22 Cal.App.5th 489, 504.)
There is overlap in dictionary definitions of the terms “knowingly” and
“intentionally”; definitions of the former sometimes refer to the latter and

45
each is considered a synonym of the other. 27 But definitions of “knowingly”
tend to focus on awareness 28 while definitions of “intentionally” tend to focus
on purpose. 29

27 For example, the Oxford English Dictionary (3d ed. 2015) (OED)
includes “intentionally” in its definition of “knowingly” (OED Online
[as of
Mar. 11, 2022]); Merriam-Webster’s Thesaurus lists “intentionally” and
“knowingly as synonyms for each other. (Merriam-Webster’s Thesaurus
Online [as of
Mar. 11, 2022];
[as of Mar. 11, 2022].)
28 For example, “knowingly” is defined by the OED as “[w]ith
knowledge or awareness (of what one is doing, of a fact, etc.); consciously,
intentionally.” (OED Online

[as of Mar. 11, 2022]) and by Merriam-Webster Unabridged Dictionary
(Merriam-Webster) as “with awareness, deliberateness, or intention”
(Merriam-Webster Dict. Online [as of Mar. 11, 2022]). Black’s Law
Dictionary defines “knowing” as “[h]aving or showing awareness or
understanding; well-informed” and “[d]eliberate; conscious,” and “knowingly”
as “[i]n such a manner that the actor engaged in prohibited conduct with the
knowledge that the social harm that the law was designed to prevent was
practically certain to result; deliberately.” It explains: “A person who acts
purposely wants to cause the social harm, while a person who acts knowingly
understands that the social harm will almost certainly be a consequence of
the action, but acts with other motives and does not care whether the social
harm occurs.” (Black’s Law Dict. supra, p. 1042, col. 2.)
29 Examples include “with intention, on purpose” (OED Online

[as of Mar. 11, 2022]) and “in an intentional manner: with intention:
purposely” (Merriam-Webster Dict. Online [as of Mar. 11, 2022). Black’s Law
Dictionary, supra, page 965, defines “intentional” as “[d]one with the aim of
carrying out the act.”

46
 To give significance to each word used in Health and Safety Code
section 25249.6, it is more reasonable to view “intentionally” as adding this
concept of purpose than as giving “knowingly” a different meaning than it
would have when used on its own. We see no basis for reading “intentionally”
in section 25249.6 as essentially modifying “knowingly” to require a higher
level of knowledge than “knowingly” would otherwise convey. As we have
said, an actual knowledge requirement would narrow the scope of section
25249.6, contrary to the purpose of Proposition 65. (See California
Manufacturers & Technology Assn. v. State Water Resources Control Bd.
(2021) 64 Cal.App.5th 266, 281–282 [statutory term with alternative
definitions construed as intended to carry the meaning more consistent with
legislative purpose].) The inclusion of “intentionally” in this statute, as
opposed to section 25249.5, is an insufficient basis for the interpretation
Amazon seeks. 30
Finally, Amazon points to the absence in Proposition 65 of language
often used to indicate a statute contemplates constructive knowledge. (E.g.,

30 One explanation for the distinction in language between these two
statutes might lie in the different degree of regulation each provides. Health
and Safety Code section 25249.5 is an outright prohibition against
contamination of drinking water. In prohibiting businesses from “knowingly”
discharging or releasing listed chemicals into water or land where they
probably will pass into a source of drinking water, this statute appears to
contemplate liability when the business is aware that the discharge or
release it causes contains the listed toxin and is likely to reach a source of
drinking water, regardless of whether it intends this result. Health and
Safety Code section 25249.5 is less restrictive, requiring warnings but not
prohibiting the act that causes exposure to the chemical. In keeping with
this lower level of regulation, the statutory requirement is triggered only
where the defendant is not only aware but also intends to take the action that
results in the exposure—in the case of a consumer product, intends to take
the action that moves the product toward the consumer.

47
Labor Code, § 2810 [“A person or entity shall not enter into a contract or
agreement for labor or services . . . where the person or entity knows or
should know that the contract or agreement does not include funds sufficient
to allow the contractor to comply with all applicable . . . laws . . .”]; Civ. Code,
§ 3426.1 [“ ‘Misappropriation’ means: [¶] (1) Acquisition of a trade secret of
another by a person who knows or has reason to know that the trade secret
was acquired by improper means”].) While the presence of such language
may compel a conclusion that the statute encompasses constructive
knowledge, its absence is not dispositive. (E.g., PacifiCare Life & Health Ins.
Co. v. Jones (2018) 27 Cal.App.5th 391, 417–418 [upholding regulation
defining “knowingly,” in statute delineating unfair and deceptive insurance
business practices, as including constructive knowledge]; Tsasu, supra,
62 Cal.App.5th at pp. 717–721 [construing “knowledge” in quiet title statute
as including constructive knowledge].)
We conclude the trial court erred in ruling that Lee was required to
prove Amazon had actual knowledge the products at issue contained mercury
and excluding evidence of constructive knowledge. Of course, this error
would be of no consequence if Lee is correct that the record demonstrates
substantial evidence of actual knowledge as a matter of law. Lee argues
Amazon had actual knowledge of the mercury in the Faiza and Face Fresh
skin-whitening creams from the RAPEX notices and for the Monsepa cream
from Lee’s notice of violation. He does not contend Amazon had actual
knowledge as to the Meiyong products.
Lee’s argument is strongest with respect to the Monsepa cream. Lee
asserts that a notice of violation necessarily establishes actual knowledge,
citing the definition of Regulations section 25600.2, subdivision (f)(2), which
expressly treats a notice of violation as a source of a retail seller’s actual

48
knowledge. 31 As we have said, Regulations section 25600.2 is not applicable
to the present case. But “[p]roof of actual knowledge focuses on what
information a defendant must have been aware of” (People v. ConAgra
Grocery Products Co., supra, 17 Cal.App.5th at pp. 84–85), and the notice of
violation was directly served on Amazon.
Amazon does not dispute the general proposition that a notice of
violation establishes actual knowledge, but it argues the notice in the present
case was insufficient to do so. The notice of violation named Amazon and
aztopselstore.com (the distributor of Monsepa cream) as violators, specified
the chemical (“Mercury”), routes of exposure (“Ingestion, Dermal, Inhalation”)
and type of harm (“Developmental Toxin”), and identified the products as
“[s]kin-lightening creams” with “Monsepa Express Peeling Night Face
Cream, 15 mL size” as an example. Amazon argues the reference to “[s]kin-
lightening creams” did not provide notice as to any specific product, and the
CDPH’s investigation, which found mercury in only seven of over a hundred
skin-lightening creams tested, demonstrated most such creams do not contain
mercury. Amazon further argues the fact that the notice of violation named
“Monsepa Express Peeling Night Cream” was insufficient to establish
knowledge because the product Lee had tested for this litigation has a

31 The regulation states that “ ‘[a]ctual knowledge’ means the retail
seller receives information from any reliable source that allows it to identify
the specific product or products that cause the consumer product exposure”
and “[w]here the source of a retail seller’s knowledge is a notice pursuant to
[Health and Safety Code] Section 25249.7(d)(1) of the Act, the retail seller
shall not be deemed to have actual knowledge of any consumer product
exposure alleged in the notice until five business days after the retail seller
receives the notice. The notice must provide sufficient specificity for the
retail seller to readily identify the product or products subject to the notice, in
accordance with Article 9, section 25903(b)(2)(D).” (Regs., § 25600.2,
subd. (f)(1), (2).)

49
different name (“Monsepa Express Peeling” per packaging; “Monsepa Express
Peeling Remove Dark Spots Face Cream” on Amazon listing).
Amazon’s argument is not persuasive. As Lee points out, the
regulations require a notice of violation to provide “the name of the consumer
product or service, or the specific type of consumer product or services, that
cause the violation, with sufficient specificity to inform the recipients of the
nature of the items allegedly sold in violation of the law and to distinguish
those products or services from others sold or offered by the alleged violator
for which no violation is alleged.” (Regs., § 25903, subd. (b)(2)(D).) OEHHA
has explained that this regulation is meant to avoid identification of the
products at issue in “very broad terms, such as ‘various aerosol, paint,
adhesive and/or automotive products, including but not limited to,’ ” that are
“inadequate to describe the nature of the violation that is claimed.”
(OEHHA, Final Statement of Reasons, Adopt Section 12908, Notices of
Violation, title 22, Division 2, California Code of Regulations, p. 10.) On the
other hand, the agency stated, “[c]learly it would be sufficient simply to say
‘aerosol spray paint,’ ‘car wax’ or ‘paint thinner.’ Such a description would at
least identify the category of products that will be the subject of the action,
and would enable the public agency to focus the investigation.” (Ibid.)
Lee’s notice of violation satisfied these parameters. The notice of
violation informed Amazon that a category of products—“skin-lightening
creams”—allegedly caused exposure to mercury and specifically named one
such product. Although the product Lee had tested was identified with a
slightly different name on the Amazon Web site, the notice, Web site listing,
and product packaging all used the distinctive “Monsepa Express Peeling”
identifier. In our view, this constituted notice that the Monsepa skin-

50
lightening cream Lee put at issue here was alleged to contain mercury and,
thus, was evidence of actual knowledge.
In arguing Amazon had actual knowledge that the Faiza and Face
Fresh creams contained mercury from the RAPEX notices for these products,
Lee relies on Kosnoff’s testimony that Amazon employees in Europe review
RAPEX notices; Amazon would have been aware of the 2013 RAPEX notice
for Faiza Beauty Cream; and he was aware a “very similar” product was
listed on the American Web site. This testimony is less definitive proof of
actual knowledge than the evidence regarding the Monsepa cream: Kosnoff
described a general business practice that would be expected to result in
Amazon’s awareness of the RAPEX notices, but his testimony also raised
questions about the relationship between and management of Amazon’s
European and American Web sites which are not addressed by any evidence
in the record. The RAPEX notices may well provide persuasive evidence of
constructive knowledge, but we cannot find them sufficient to establish
actual knowledge as a matter of law so as to overturn the trial court’s finding
of no actual knowledge.
Because the trial court precluded evidence of constructive knowledge,
we have no means of evaluating whether Lee will be able to make a showing
sufficient to alter the ultimate outcome of this case. 32 Evidence of

32 In finding Amazon did not have actual knowledge that the skin-
lightening creams contained mercury, the trial court noted that mercury was
not identified as an ingredient on the packaging or product detail pages. Lee
argues the absence of information on a product’s label cannot be the basis for
finding an absence of actual knowledge, an argument also maintained by the
Attorney General in his amicus brief; otherwise, Amazon could avoid liability
even if it was informed by the third-party seller or any other reliable source
that the product contained mercury. We do not read the trial court as having
held the absence of information on the products’ packaging or product detail
pages was dispositive of the actual knowledge issue; the court went on to say

51
constructive knowledge must be evaluated in the context of all relevant
circumstances bearing on what Amazon had reason to know or reasonably
should have known. This will presumably include facts related to Amazon’s
business operations and role in bringing the products to customers as well as
the statutory context.
With regard to the latter, Health and Safety Code section 25249.11,
subdivision (f), makes clear that the Legislature did not intend all parties
involved in bringing a consumer product into the hands of the consumer to
bear the same responsibility for providing the warnings required by
Proposition 65 and, specifically, intended to minimize the burden on retail
sellers in most cases. Amazon’s assertion that it is not a retail seller is part
of its broader argument that it is not a part of the chain of distribution at all,
and therefore not subject to section 25249.6. As we have said, this broader
argument unsustainable. But Amazon’s fallback position—that if it is part of
the chain of distribution, the only thing it can be considered is a retail
seller—is not unreasonable. There is no evidence to support characterizing
Amazon as a manufacturer, producer, packager, importer, or distributor of
the products at issue. Regardless of whether it comes within ordinary
definitions of “retail seller” or can be considered a “seller” if it does not take
title of the product in question (see Milo & Gabby LLC v. Amazon.com, Inc.
(Fed. Cir. 2017) 693 Fed. Appx. 879, 890 [Amazon not a “seller” for purposes
of copyright infringement claim]), Amazon’s role in the present case was

that Lee failed to establish Amazon had actual knowledge “at any earlier
time,” perhaps a reference to evidence such as the RAPEX notices and CDPH
notice. It should be obvious that while packaging indicating a listed toxin is
an ingredient would supply actual knowledge, absence of such information on
product labeling, in and of itself, is far too limited a basis for finding an
absence of knowledge, actual or otherwise.

52
analogous to a retail seller’s for purposes of Health and Safety Code section
25249.6 in that Amazon had nothing to do with determining the contents,
manufacturing or labelling of the skin-lightening products. As OEHHA noted
regarding the 2016 regulations, entities such as manufacturers, producers
and packagers “usually will have greater knowledge than retailers of a
product’s chemical content and whether it causes chemical exposures that
require a warning.” (2016 FSOR, supra, p. 35.) Still, Amazon made the
products available for purchase by the ultimate consumer and, at a
minimum, facilitated the sale by providing a forum for it to take place,
handling the finances of the transaction and controlling communications
between the customer and the third-party sellers. All these facts may be
relevant considerations with respect to what knowledge can be attributed to
Amazon.
III.
The trial court found Lee failed to prove that Amazon exposed
consumers to mercury because he did not prove anyone actually used the
skin-lightening products at issue. The trial court noted that Lee “did not
present any evidence of exposure related to any of the product purchasers,
despite obtaining those purchasers’ contact information from Amazon during
discovery”; the evidence established “there has been a public campaign to
discourage the use of skin-lightening creams that may contain mercury,
including a buy-back program for new and used products”; and “[t]here was
no evidence that anyone was exposed to mercury in connection with any of
the four units that were actually purchased by plaintiff’s counsel through
Amazon’s marketplace.”
Lee maintains the trial court’s interpretation of “expose” improperly
narrowed the scope of Proposition 65, imposing a burden that would make it

53
all but impossible to enforce the law with respect to consumer products due to
the expense of obtaining evidence that more than a minimal number of
people opened and used a product they purchased. Lee points out that
consumer products may be sold to millions of customers, many of whom may
remain anonymous if the products were purchased in stores that do not keep
records of individual purchasers or, if identifiable, may be unwilling to
participate in litigation.
Moreover, Lee argues, proof of individual consumers’ use of the
products is unnecessary because common sense dictates a conclusion that
people purchase products in order to use them. Lee and the Attorney General
both point to the statutory maxim that “[t]hings happen according to the
ordinary course of nature and the ordinary habits of life.” (Civ. Code, § 3546.)
Thus, the Attorney General, drawing on his experience in enforcing
Proposition 65, states he “always assumed that people who buy cookies eat
them; people who buy sodas drink them; and people who buy skin creams
apply them to their skin.” The Attorney General states, “companies do not
sell products that their customers will not use, and consumers do not buy
skin creams unless they intend to apply them to their skin. Accordingly, in
his cases, the Attorney General has not provided declarations from
consumers that they ate the lead-containing cookies, took the vitamins, or
used the anti-diarrheal medicine that have been the subject of his Proposition
65 claims” and no court has “ever even suggested that such evidence was
necessary.” Indeed, as Lee points out, when Lee sought a preliminary
injunction in this case, one of Amazon’s arguments in opposition was that the
request was made two years after the complaint was filed and, “[b]ecause
Amazon blocked the sale of the relevant Products long ago, the only

54
reasonable inference is that the Products have been completely used since
they were last purchased.”
The Proposition 65 regulations define “expose” as meaning “to cause to
ingest, inhale, contact via body surfaces or otherwise come into contact with a
listed chemical. An individual may come into contact with a listed chemical
through water, air, food, consumer products and any other environmental
exposure as well as occupational exposures.” (Regs., § 25102, subd. (i).) In
article 6, “Clear and Reasonable Warnings,” “[c]onsumer product exposure” is
defined as “an exposure that results from a person’s acquisition, purchase,
storage, consumption, or any reasonably foreseeable use of a consumer
product, including consumption of a food. (Regs., § 25600.1, subd. (e).) When
this regulation was adopted in 2016, OEHHA’s FSOR included the statement,
“If a person’s use of a product is ‘reasonably foreseeable’ even if it is not
entirely consistent with label recommendations, any resulting exposures to
listed chemicals can properly be considered to be ‘knowing and intentional’ on
the part of the product manufacturer, and are therefore subject to Proposition
65.” (2016 FSOR, supra, p. 31.)
The trial court viewed the definition of “consumer product exposure” as
requiring proof of an “actual ‘exposure’ ” and the agency’s explanatory
statement as confirming that “foreseeability may impact knowledge and
intent, but it does not eliminate the requirement of exposure.” In our view,
however, the regulatory definition of “consumer product exposure” provides
less insight into the meaning of “expose” as used in Health and Safety Code
section 25249.6 than the trial court attributed to it. The explanatory
statement the trial court noted was in response to a comment seeking to alter
the definition of “consumer product exposure” by replacing the phrase “any
reasonably foreseeable use of a product” with “use of a product in accordance

55
with recommendations made in the product’s labels or labeling or with other
actual and accepted uses of the product” or “use of the product in accordance
with the product labeling recommendations or ordinary conditions of use.”
(2016 FSOR, supra, p. 31.) OEHHA rejected the proposed revision because it
would “unnecessarily limit the potential exposure scenarios to listed
chemicals” and “[l]imiting the scope of the definition would not be consistent
with the Act.” (Ibid.) The foreseeability issue addressed in the agency’s
statement pertained only to the “use” component of the provision defining
“consumer product exposure,” serving to limit the extent to which a business
subject to Proposition 65 is required to anticipate the ways its product might
be used. No such clarification was necessary for the other sources of exposure
listed in the regulation (purchase, acquisition, storage).
The regulation defines “consumer product exposure” by describing the
sources from which an exposure can result, but it does not define what
“exposure” actually consists of. The phrase “consumer product exposure”
appears in article 6 of the Act (“Clear and Reasonable Warnings”), in
regulations describing the required contents of Proposition 65 warnings and
methods by which they may be provided. (Regs., §§ 25601, 25602, 25603.)
Regulations section 25600, subdivision (a), provides that “[n]othing in Article
6 shall be interpreted to determine whether a warning is required for a given
exposure under Section 25249.6 of the Act.” The original lead agency also
distinguished between the definition of “consumer product exposure” and the
definition of “expose” for purposes of Health and Safety Code section 25249.6.
Responding to a comment that “consumer exposures are triggered by the
purchase of a product, rather than by consumption,” the agency stated: “The
definition of ‘consumer products exposure,’ however, is not intended to
establish when an exposure occurs.· It is intended to address the availability

56
of the ‘safe harbor’ warning. The term ‘expose’ is defined elsewhere as
meaning ‘to cause to ingest, inhale, contact via body surfaces or otherwise
come into contact with a chemical.’ ” (Former Cal. Code Regs., tit. 22,
§ 12201, subd. (f) [now tit. 27, § 25102, subd. (i)].) “This could include the
purchase by an individual of a product, not just the consumption of that
product.” (1988 FSOR, supra, p. 10.) 33

Arguing that this agency explanation “does not establish that an
33

exposure necessarily occurs only from a purchase,” Amazon points to
statements in the 2016 FSOR which it says explain that “a person who
purchases a product is not necessarily exposed” and “[i]n some cases,
exposure will not occur until the product packaging is opened.”
The first of these statements (italicized below) is part of a comment
submitted to OEHHA regarding its proposed regulation defining “retail
seller” (Regs., § 25600, subd. (l)): “In the definition for ‘retail seller,’ the term,
‘purchasers’ should be changed to ‘consumers,’ both for consistency and to
avoid inadvertently including wholesale distributors. Often, the consumer of
the product, and thus the individual who is exposed, is not the purchaser.”
(2016 FSOR, supra, p. 33.) OEHHA responded that it agreed and had
replaced the term “purchasers” with “consumers.” (Ibid.) Read in context, it
is apparent that the point was to avoid language that might be taken as
extending the regulation restricting circumstances in which retail sellers are
required to provide Proposition 65 warnings to sellers that do not sell directly
to consumers, not to suggest that sale to a consumer does not expose the
consumer to a listed chemical in the product.
The second statement (italicized below) is from the OEHHA’s response
to a comment that a proposed regulation specifying methods for providing
safe harbor consumer product exposure warnings (Regs., § 25602, subd. (a))
was unclear as to “whether a warning is required on both the immediate
container and the outer packaging of a product.” (2016 FSOR, supra, p. 87.)
OEHHA responded in the negative, explained that the regulations provided
several options for warnings, then stated, “[t]he warning should be placed in
such a manner as to ensure that it is seen and understood prior to exposure.
For example, . . . if a person will be exposed to a listed chemical immediately
upon opening a product’s outer packaging through contact with the product,
the warning should be placed on the outer container or wrapper.” (Ibid.) This
guidance is obviously directed at those in a position to provide warnings on

57
 Lee’s claim in the present case is that Amazon violated the requirement
of Health and Safety Code section 25249.6 that a business shall not
knowingly and intentionally “expose” any individual to a listed chemical
without first providing clear and reasonable warning. The ordinary
definition of “expose” is “[t]o lay open (to danger, ridicule, censure, etc.).”
(OED, “expose” OED Online
[as of Mar. 11, 2022]; Merriam-Webster Dict. Online, “expose” [“to
lay open (as to attack, danger, trial, or test)”] [as of Mar. 11, 2022].) The original lead
agency expressly relied upon this general definition of “expose” in explaining
the rule it adopted for calculating whether a business employs 10 or fewer
employees (and therefore is not subject to the requirements of Proposition
65). (1988 FSOR, supra, pp. 19, 26
[as of
Mar. 11, 2022].) The rule requires counting all full- and part-time employees
“on the date on which the discharge, release or exposure occurs.” (Former
Cal. Code Regs., tit. 22, § 12102; now tit. 27, § 25102, subd. (h).) Discussing
the rule in the context of exposure to agricultural products, the agency
rejected the assumption that exposure occurs on the date the product is
consumed: “In fact, nothing provides that exposure occurs only at the time a
particular consumer good is consumed. The term ‘expose’ generally means ‘to
lay open,’ as to something which is injurious or dangerous. Laying an
individual open to a chemical hazard through a consumer product could

products and their packaging, such as manufacturers and packagers, to
ensure such warnings are not placed where they may be overlooked by the
consumer. It does not address the meaning of “expose” with respect to a
business that sells a product to the consumer.

58
result from any act which propels the product toward the individual.” (1988
FSOR, p. 19.)
This interpretation makes clear that the original lead agency
understood its definition of “expose” to refer to any act that brings the
product containing a listed chemical into contact with an individual,
regardless of the individual’s actual use. “Expose,” in other words, refers to
potential exposure as well as realized exposure. The regulatory definition of
“expose” has not changed in any meaningful way, and we are not aware of
any departure from the lead agency’s original interpretation. That
interpretation is consistent with the statutory requirement that Proposition
65 warnings be provided before an individual is exposed to a listed chemical.
(Health & Saf. Code, § 25249.6.) Necessarily, consumer product exposure
warnings must be provided prior to or concurrent with sale to the retail
consumer; once the product has reached the consumer, the seller,
manufacturer or other party in the chain of distribution would have no means
of providing a warning. The regulations’ safe harbor warning requirements
for consumer products specify that the warning must be provided by one or
more of four means, all of which entail visibility to the consumer prior to or
during a purchase; 34 for Internet purchases, warnings must be provided prior
to completion of the purchase. (Regs., § 25602, subds. (a) & (b).)

34 These means are: “A product-specific warning provided on a posted
sign, shelf tag, or shelf sign, for the consumer product at each point of display
of the product”; “A product-specific warning provided via any electronic device
or process that automatically provides the warning to the purchaser prior to
or during the purchase of the consumer product, without requiring the
purchaser to seek out the warning”; “A warning on the label that complies
with the content requirements in Section 25603(a)”; and/or “A short-form
warning on the label that complies with the content requirements in Section
25603(b)” and is in a specified type size. (Regs., § 25602, subd. (a)(2)-(4).)

59
 Interpreting “expose” by its ordinary meaning is also consistent with
Proposition 65’s protective purpose. As we have said, the preamble to
Proposition 65 expressly invoked the voters’ “rights” to “be informed about
exposures to chemicals that cause cancer, birth defects, or other reproductive
harm[,]” and to “secure strict enforcement of the laws controlling hazardous
chemicals and deter actions that threaten public health and safety.” (Ballot
Pamp., supra, p. 53.) Proposition 65 is not primarily about punishment for
harm that has been inflicted; it is about protection from harmful chemicals,
the ability to make informed choices about coming into contact with such
chemicals, and deterrence of conduct that undermines these purposes. The
interpretation of Health and Safety Code section 25249.6 advanced by
Amazon and adopted by the trial court would absolve a business that
knowingly and intentionally, without warnings, sold a product whose
intended use would necessarily cause the consumer to ingest, inhale or
otherwise come into bodily contact with a listed chemical, if the consumer
happened not to use the product he or she purchased. This cannot be what
the voters who enacted Proposition 65 intended.
The trial court cited Consumer Cause v. Weider Nutrition Internat.
(2001) 92 Cal.App.4th 363, 370, for its statement that “[former section]
12201, subdivision (f) [now Cal. Code Regs., tit. 27, § 25102, subd. (i)] defines
exposure in terms of a chemical . . . coming into contact with a person.”
Consumer Cause did not consider whether selling or otherwise providing a
product containing a listed chemical to a consumer constitutes exposing the
consumer to the chemical. The issue in that case was whether the
defendants exposed consumers to cancer-causing chemicals through products
that did not contain any listed chemical but, when ingested, caused a
chemical reaction in the body that increased natural levels of testosterone,

60
which can cause cancer. Holding the defendants’ products did not expose
consumers to cancer-causing chemicals within the meaning of Proposition 65,
the Consumer Cause court explained that “ ‘[t]he Act prohibits all means of
directly bringing individuals into contact with chemicals known to the state
to cause cancer . . .’ ” and the products at issue did not do so, since the
increase in testosterone occurred only as a result of a reaction inside the
body. (Consumer Cause, at p. 369.) The court further emphasized that ballot
materials for Proposition 65 “focus[ed] on exposure to carcinogenic chemicals”
and did not suggest Proposition 65 “was intended to apply when a person is
exposed to a noncarcinogenic chemical which then causes a substance
naturally occurring in the body to become carcinogenic.” (Consumer Cause,
at p. 370.)
Amazon argues that the need for evidence of “actual exposure” was
particularly important in the present case because the total number of sales
at issue was relatively small and there was a public health campaign to
discourage use of skin-lightening creams, including a buy-back program that
recovered some products before they were used. Aside from factual questions
such as whether consumers who purchased the products at issue were aware
of the public health notices or participated in the buy-back program, this
argument begs the relevant question. The argument is premised on the
assumption that Amazon cannot be said to have exposed a consumer to
mercury in a skin-lightening cream unless and until the consumer has
actually applied the cream to his or her skin. As we have explained, however,
we understand “expose” as used in Health and Safety Code section 25249.6 as
referring to potential as well as realized exposure from a product being used
in the intended manner—“[l]aying an individual open to a chemical hazard”

61
by an “act which propels the product toward the individual.” (1988 FSOR,
supra, p. 19.)
Amazon certainly meets this definition. As described by the court in
Bolger, supra, 53 Cal.App.5th at page 438, “Amazon placed itself between
[the third-party seller and customer] in the chain of distribution of the
product at issue here” by attracting customers to the Amazon Web site,
providing product listings for the skin-lightening creams, receiving payment
for the products, requiring communication between third-party sellers and
customers to go through the Amazon Web site, demanding indemnification
and fees for each purchase, and, for products using the FBA program,
accepting possession of the product, storing it in an Amazon warehouse, and
shipping it to the customer. “Whatever term we use to describe Amazon’s
role, be it ‘retailer,’ ‘distributor,’ or merely ‘facilitator,’ it was pivotal in
bringing the product here to the consumer.” (Ibid.)
Finally, Amazon argues we should infer Lee attempted but was unable
to discover any evidence of “actual exposure” from the fact that Lee obtained
an order from the trial court compelling Amazon to provide contact
information for purchasers of the products at issue, but did not present any
evidence of actual use of the products. Lee’s motion to compel argued the
contact information was “primarily relevant because it relates to Amazon’s
defense that it should not be required to send warnings to purchasers ‘who
have since used all the products,” 35 as Amazon had not offered any evidence

35 When Lee sought a preliminary injunction, one of Amazon’s
arguments in opposition was that “[i]f the injunction is entered, Amazon will
be required to email purchasers of third-party products who have since used
all the Products—informing them that products they used might have
contained mercury . . . ,” which would not prevent further violations of
Proposition 65, but “simply upset Amazon’s customers, over products Amazon
didn’t even sell.” The trial court denied the request for this emailed notice.

62
that customers were no longer using the creams they purchased. Lee also
argued the customer contact information would lead to discovery of percipient
witnesses and material relevant to Amazon’s liability, with respect to both
exposure and Amazon’s operations and knowledge. In granting the motion to
compel, the trial court found Lee had “sufficiently shown that the contact
information of consumers who purchased the skin creams may well lead to
relevant and/or admissible information, including as to: (1) the nature of the
transactions and Amazon’s role in them; (2) the extent to which a Proposition
65 warning was available or known to the consumer; (3) the extent to which
the consumers (or their family members) were exposed to the product; (4) the
extent to which exposures continue; and (5) whether there was any
communication with Amazon about the mercury or other content.” Amazon
provided access to the customer contact information.
Neither the record nor Lee’s briefs explain why he did not present
evidence of individual consumers’ use of the skin-lightening products. But we
see no reason to infer customers who purchased skin-lightening creams
through the Amazon Web site did not use them. “Things happen according to
the ordinary course of nature and the ordinary habits of life.” (Civ. Code,
§ 3546.) It is at least as likely Lee was unable to locate purchasers of the
products willing to participate in this litigation, or decided not to pursue this
source of potential evidence. Regardless, in light of our interpretation of
Health and Safety Code section 25249.6, evidence of actual use was not
necessary to establish the “expose” element of Lee’s claims. 36

36We are not persuaded by Lee’s argument that the trial court
precluded him from presenting the evidence of use it then found he failed to
present. Lee points out that when his attorney asked Copan what evidence
the CDPH found that skin-whitening cream was responsible for mercury
contamination in homes, the trial court sustained Amazon’s objection that

63
 IV.
Lee contends the trial court erred in finding Amazon immune from
liability for violating Proposition 65 under section 230 of the federal CDA.
(§ 230(c)(1).) In relevant part, that section states, “No provider or user of an
interactive computer service shall be treated as the publisher or speaker of
any information provided by another information content provider.” (Ibid.)
The statute expressly preempts state laws that are inconsistent with its
terms: “Nothing in this section shall be construed to prevent any State from
enforcing any State law that is consistent with this section. No cause of
action may be brought and no liability may be imposed under any State or
local law that is inconsistent with this section.” (§ 230(e)(3).)
“ ‘Taken together, these provisions bar state-law plaintiffs from holding
interactive computer service providers legally responsible for information
created and developed by third parties. [Citation.] Congress thus
established a general rule that providers of interactive computer services are
liable only for speech that is properly attributable to them. [Citation.] State-

these investigations had no connection to products sold through Amazon.
Lee’s attorney stated that Amazon’s brief had “argued there was no way to
prove exposure from people purchasing skin-lightening creams” and “[w]hile
it may seem rather obvious, I feel we now need to prove that people who use
products that they purchase, and Ms. Copan has personal knowledge of how
people have used other skin-lightening creams.” The court responded, “I
don’t think the Judge needs a witness on that. I’m going to have to make a
decision as to the application of the regs and the statue, as to whether ‘ingest’
means to physically ingest or whether it’s reasonably foreseeable a product
will be used in the manner anticipated. . . . I don’t need Ms. Copan for that.
[¶] As my father would say, that’s common sense. The issue is what the law
is.” What the court precluded was testimony about how skin-lightening
creams are used in general; what the court subsequently found lacking in
Lee’s case was evidence that the specific products at issue in this case were in
fact used by a consumer after being purchased through Amazon’s Web site.

64
law plaintiffs may hold liable the person who creates or develops unlawful
content, but not the interactive computer service provider who merely
enables that content to be posted online.’ (Nemet Chevrolet, Ltd. v.
Consumeraffairs.com, Inc. (4th Cir. 2009) 591 F.3d 250, 254.)” (Bolger, supra,
53 Cal.App.5th at p. 463.)
“ “[S]ection 230(c)(1) precludes liability that treats a website as the
publisher or speaker of information users provide on the website. In general,
this section protects websites from liability for material posted on the website
by someone else.” (Doe v. Internet Brands, Inc. (9th Cir. 2016) 824 F.3d 846,
850 (Internet Brands, Inc.).) “Immunity under section 230 extends to ‘ “(1) a
provider or user of an interactive computer service (2) whom a plaintiff seeks
to treat, under a state law cause of action, as a publisher or speaker (3) of
information provided by another information content provider.” ’
(HomeAway.com, Inc. v. City of Santa Monica (9th Cir. 2019) 918 F.3d 676,
681 (HomeAway.com).)” (Bolger, supra, 53 Cal.App.5th at p. 463.)
“[P]ublication involves reviewing, editing, and deciding whether to publish or
to withdraw from publication third-party content . . . . [A] publisher reviews
material submitted for publication, perhaps edits it for style or technical
fluency, and then decides whether to publish it.” (Barnes v. Yahoo!, Inc. (9th
Cir. 2009) 570 F.3d 1096, 1102–1103 (Barnes).)
The trial court concluded all the elements of CDA immunity were
satisfied in the present case, finding Amazon is an interactive computer
service provider, Lee’s claim is “predicated on information provided by
another information content provider (i.e., the third-party sellers that
provided the product descriptions without a Proposition 65 warning),” 37 and

The trial court quoted Oberdorf v. Amazon.com Inc. (M.D.Pa. 2017)
37

295 F.Supp.3d 496, 501, a products liability case in which the district court

65
Lee “seeks to treat Amazon as the publisher or speaker of that information.”
The trial court viewed Lee’s claims as seeking to impose liability on Amazon
for “allowing third parties to list products for sale on its website without
altering the disclosures and other content supplied by those third parties as
to their own manufactured products.”
Lee does not suggest Amazon is not an interactive computer service
provider within the meaning of section 230, and does not dispute that the
product descriptions for products sold on the Web site by third parties are
provided by those parties. 38 He argues, however, that his claims are not
precluded by section 230 because they do not seek to treat Amazon as the
publisher or speaker of information provided by the third-party sellers, but

stated, “ ‘Like an auctioneer, Amazon is merely a third-party vendor’s “means
of marketing,” since third-party vendors—not Amazon—“cho[o]se the
products and expose[]” them for sale by means of: the Marketplace.’ ” The
same day the trial court entered judgment, Oberdorf was affirmed in part
and vacated in part (Oberdorf v. Amazon.com Inc. (3d Cir. 2019) 930 F.3d
136, 153–154) in a decision which was then vacated when a petition for
rehearing en banc was granted (Oberdorf v. Amazon.com Inc. (3d Cir. 2019)
936 F.3d 182). The Third Circuit has since certified for review by the
Pennsylvania Supreme Court the question whether, under Pennsylvania law,
an “e-commerce business, like Amazon” is strictly liable for a defective
product in the circumstances of that case. (Oberdorf v. Amazon.com, Inc. (3d
Cir. 2020) 818 Fed. Appx. 138, 143.)
38 “Section 230 defines an ‘ “interactive computer service” ’ as ‘any
information service, system, or access software provider that provides or
enables computer access by multiple users to a computer server, including
specifically a service or system that provides access to the Internet and such
systems operated or services offered by libraries or educational institutions.’
(§ 230(f)(2).) The term ‘ “information content provider,” ’ meanwhile, ‘means
any person or entity that is responsible, in whole or in part, for the creation
or development of information provided through the Internet or any other
interactive computer service.’ (§ 230(f)(3).)” (Hassell, supra, 5 Cal.5th at
p. 535.)

66
rather to hold Amazon accountable for violation of its own independent
obligations under Proposition 65.
“Congress enacted section 230 ‘for two basic policy reasons: to promote
the free exchange of information and ideas over the Internet and to
encourage voluntary monitoring for offensive or obscene material.’ ” (Hassell
v. Bird (2018) 5 Cal.5th 522, 534 (Hassell), quoting Carafano v.
Metrosplash.com, Inc. (9th Cir. 2003) 339 F.3d 1119, 1122.) The Ninth
Circuit has explained: “As the heading to section 230(c) indicates, the
purpose of that section is to provide ‘[p]rotection for “Good Samaritan”
blocking and screening of offensive material.’ That means a website should
be able to act as a ‘Good Samaritan’ to self-regulate offensive third party
content without fear of liability.” (Internet Brands, Inc., supra, 824 F.3d at
pp. 851–852.)
Section 230 was enacted in part in reaction to an unpublished state
court decision 39 holding that “an internet service provider became a
‘publisher’ of offensive content on its message boards because it deleted some
offensive posts but not others.” (Internet Brands, Inc., supra, 824 F.3d at
p. 852.) Under the state court’s reasoning “a website had to choose between
voluntarily removing some offensive third party content, which would expose
the site to liability for the content it did not remove, or filtering nothing,
which would prevent liability for all third party content. [Citation.] ‘In
passing section 230, Congress sought to spare interactive computer services
this grim choice by allowing them to perform some editing on user-generated
content without thereby becoming liable for all defamatory or otherwise
unlawful messages that they didn’t edit or delete.’ ” (Ibid., quoting Fair

39Stratton Oakmont, Inc. v. Prodigy Servs. Co., 1995 WL 323710 (N.Y.
Sup. Ct. May 24, 1995)

67
Hous. Council v. Roommates.Com, LLC (2008) 521 F.3d 1157, 1163
(Roommates.Com).) “Simply put, the immunity provision was “ ‘enacted to
protect websites against the evil of liability for failure to remove offensive
content.’ ” (Internet Brands, Inc., at p. 852.)
Congress intended section 230 “ ‘ “to promote the continued
development of the Internet and other interactive computer services . . . [and]
to preserve the vibrant and competitive free market that presently exists for
the Internet and other interactive computer services, unfettered by Federal
or State regulation.” [Citations.] To that end, CDA immunity is to be
construed broadly, “to protect websites not merely from ultimate liability, but
from having to fight costly and protracted legal battles. ” ’ (Cross v. Facebook,
Inc. (2017) 14 Cal.App.5th 190, 206, 222.)” (Bolger, supra, 53 Cal.App.5th at
p. 463.)
Quoting Gentry v. eBay, Inc. (2002) 99 Cal.App.4th 816, 828 (Gentry),
the trial court stated that section 230(c)(1) “preempts state law and ‘by its
“plain language,” created a federal immunity to any cause of action that
would make interactive service providers liable for any information
originating with a third-party user of this service.’ ” In the trial court’s view,
“all of the content at issue was provided by third-party sellers, not Amazon,”
the third-party sellers did not provide Proposition 65 warnings and “[t]hus, if
there is liability here, it is predicated entirely on the deficiencies in third-
party content on Amazon’s online marketplace.” The trial court described
Lee’s claim as seeking to “treat Amazon as the publisher or speaker” of
“information provided by another information content provider (i.e., the
third-party sellers that provided the product descriptions without a
Proposition 65 warning)” and held it would be inconsistent with section
230(c)(1) to impose liability on Amazon for “failing to include a warning on

68
products sold on its website by third parties, based on product content
developed by those third parties without any encouragement, assistance or
direction from Amazon, and without evidence that Amazon was aware of the
chemical content of those products before allowing the third parties to list
them on its website.” The court viewed Lee’s claims as based on Amazon
“allowing third parties to list products for sale on its website without altering
the disclosures and other content supplied by those third parties as to their
own manufactured products.”
Amazon views Gentry as “determinative precedent.” In that case,
purchasers of what turned out to be forged autographed sports memorabilia
alleged eBay violated Civil Code section 1739.7, which requires dealers of
collectibles to furnish a certificate of authenticity to purchasers of
autographed sports collectibles. (Gentry, supra, 99 Cal.App.4th at p. 820.)
Although the plaintiffs argued they were attempting to enforce eBay’s
independent duty to furnish a warranty under Civil Code section 1739.7, the
Gentry court held section 230 barred the claims because imposing liability on
eBay would hold it responsible, as publisher, for content originating with
other parties, as it was the individual sellers who falsely identified the
product as authentically autographed in order to sell it on eBay. (Gentry, at
pp. 831–832.) Other causes of action were similarly barred because they
sought to hold eBay responsible for having notice of illegal conduct by third
parties and failing to take action such as withdrawing or altering the content
provided by those parties that would amount to “exercise of a publisher’s
traditional editorial functions.” (Id. at p. 835.)
We do not see Gentry as dispositive of the issues in the present case.
Lee does not suggest Amazon had any obligation to alter the content of the
product descriptions provided by the third-party sellers or even to remove the

69
listings altogether. Instead, Lee maintains Amazon should have added its
own Proposition 65 warning, pursuant to its independent obligation under
Proposition 65, based on its conduct in providing a mercury-containing
product to consumers. In Gentry, the plaintiffs’ argument that they were
seeking to enforce eBay’s independent duty to provide the warranty of
authenticity was unpersuasive because the statutory duty applied only to
dealers in sports collectibles, and the plaintiffs’ “specific allegations reveal
eBay is not in the business of selling or offering to sell the collectibles at
issue; rather, it is the individual defendants who sold the items to plaintiffs,
using eBay as a venue.” (Gentry, supra, 99 Cal.App.4th at p. 827.) Here,
Proposition 65 imposes a duty to warn on every business that “exposes” an
individual to a listed chemical. As we have said, Amazon did so by its
“pivotal” role in “bringing the product here to the consumer.” (Bolger, supra,
53 Cal.App.5th at p. 438; 1988 FSOR, p. 19 [“propel[ling] the product toward
the individual”].) Lee’s claims are based on Amazon’s conduct in exposing
consumers to mercury-containing products without providing Proposition 65
warnings, not its failure to monitor, modify or remove third parties’ listings
for the products, and thus do not require treating Amazon as speaker or
publisher of third-party content. 40

40 Like Gentry, other cases Amazon cites involved claims that
necessarily based the defendants’ alleged liability on actions traditionally
within a publisher’s role. In Cross v. Facebook, supra, 14 Cal.App.5th at
pages 194 and 207, we held CDA immunity barred claims seeking to impose
liability for Facebook’s failure to remove posts by users that allegedly incited
violence and generated death threats against the plaintiffs. Chicago
Lawyers’ Committee for Civil Rights Under Law, Inc. v. Craigslist, Inc. (7th
Cir. 2008) 519 F.3d 666, 668, 672, held section 230 barred claims that
Craigslist.com violated laws against housing discrimination by hosting user
posts advertising, for example, “no minorities” or “no children.” Eberhart v.
Amazon.com, Inc. (S.D.N.Y. 2018) 325 F.Supp.3d 393, 400, footnote. 5, which

70
 Contrary to Amazon’s characterization, enforcing its obligations under
Proposition 65 does not require it to “monitor, review, and revise” product
listings. As both Lee and the Attorney General point out, the “knowingly and
intentionally” requirement in Health and Safety Code section 25249.6 means
Amazon is required to provide a warning where it has knowledge a product
contains a listed chemical—for example, from public health alerts or direct
notice. We recognize that any responsibility to provide warnings Amazon
might have under section 25249.6 would not result in liability if the third-
party seller of a skin-lightening product itself provided a Proposition 65
warning, 41 and that Amazon would have to review the product’s packaging
and/or listing on the Web site to determine whether a warning was provided
by the third-party seller. These facts do not mean Lee’s claims necessarily
treats Amazon as a speaker or publisher of information provided by the third-
party sellers. If Amazon has actual or constructive knowledge that a product
contains mercury, it might choose to review the product listing to determine

held Amazon could not be held liable for injuries due to a defective product
sold by a third-party seller, noted in passing that section 230 would bar any
claim against Amazon “for the content it permitted [the seller] to post” on the
Web site. La Park La Brea A LLC v. Airbnb, Inc. (C.D.Cal. 2017) 285
F.Supp.3d 1097, 1106, held section 230 barred a suit by the owner of
apartments listed for rent on Airbnb.com in violation of the tenants’ lease
prohibition against subletting. Doe v. Backpage.Com, LLC (1st Cir. 2016)
817 F.3d 12, 22, applied section 230 immunity to claims that the Web site
facilitated sex trafficking by enabling sex traffickers to advertise their
victims for “escort” services. Daniel v. Armslist, LLC (Wis. 2019) 926 N.W.2d
710, held section 230 barred claims against a Web site that hosts ads by
prospective sellers and purchasers of firearms for facilitating the illegal
purchase of the weapon used in a mass shooting.
41 Regulations section 25600.2, adopted in 2016, makes clear that the
essential requirement is provision of a warning to the consumer, and
expressly permits the parties in the chain of distribution to determine which
one will be responsible for providing it.

71
whether the third-party seller had provided a Proposition 65 warning before
providing the warning itself or removing the listing. But nothing inherently
requires Amazon to do so. It could choose, instead, to act on its knowledge by
providing the warning regardless, pursuant to its own obligations under
Proposition 65.
HomeAway.com provides an example, albeit in different factual
circumstances. HomeAway and another company whose Web site similarly
allows individuals seeking rental accommodations to connect with hosts
offering such rentals, challenged a city ordinance prohibiting short-term
home rentals except for licensed home-shares in which residents remain on
site with guests. (HomeAway.com, supra, 918 F.3d at p. 679.) The plaintiffs
argued the ordinance was preempted by section 230 because it required them
to monitor and remove third-party content—listings not in compliance with
the ordinance. (Id. at p. 682.) The court explained that while the plaintiffs
might choose to monitor or remove listings, the ordinance did not require
them to do so, only to cross-reference the city’s registry of licensed rentals
before processing a requested booking. (Id. at pp. 682–683.)
As our Supreme Court has observed, “not all legal duties owed by
Internet intermediaries necessarily treat them as the publishers of third-
party content, even when these obligations are in some way associated with
their publication of this material. (See, e.g., Barnes, supra, 570 F.3d at
p. 1107 [regarding § 230 immunity as inapplicable to a claim of promissory
estoppel alleging that an Internet intermediary promised to remove offensive
content].)” (Hassell, supra, 5 Cal.5th at pp. 542–543.) Similarly, the Ninth
Circuit has said “[i]t is not enough that third-party content is involved” and
has “rejected use of a ‘but-for’ test that would provide immunity under the
CDA solely because a cause of action would not otherwise have accrued but

72
for the third-party content. [Citation.] We look instead to what the duty at
issue actually requires[.]” (HomeAway.com, supra, 918 F.3d at p. 682.) “ ‘In
evaluating whether a claim treats a provider as a publisher or speaker of
user-generated content, “what matters is not the name of the cause of action”;
instead, “what matters is whether the cause of action inherently requires the
court to treat the defendant as the ‘publisher or speaker’ of content provided
by another.” [Citation.] Put slightly differently, “courts must ask whether
the duty that the plaintiff alleges the defendant violated derives from the
defendant’s status or conduct as a ‘publisher or speaker.’ If it does, section
230(c)(1) precludes liability.” ’ (Cross [v. Facebook], supra, 14 Cal.App.5th at
p. 207.)” (Bolger, supra, 53 Cal.App.5th at p. 464.)
Bolger, supra, 53 Cal.App.5th at page 439, a products liability case
involving a defective computer battery purchased from a third-party seller on
Amazon’s Web site, held section 230 did not shield Amazon from liability
because the plaintiff’s strict liability claims “depend on Amazon’s own
activities, not its status as a speaker or publisher of content provided by [the
third-party seller] for its product listing.” The court first concluded that
Amazon’s extensive role in third-party sales, especially where the seller
utilizes the FBA program (as in Bolger and for at least one of the products
here), supported application of strict liability, describing that role in terms
consistent with the evidence in this case. (Bolger, at pp. 452–453; Loomis v.
Amazon.com LLC (2021) 63 Cal.App.5th 466 [agreeing with Bolger in case
where seller did not use FBA].) 42 After discussing two cases from other

42 The Bolger court noted that “Amazon created the environment (its
website) that allowed [the third-party seller] to offer the replacement battery
for sale”; “attracted customers through its own activities”; “set the terms of
[the seller’s] involvement”; “demanded fees in exchange for [the seller’s]
participation”; “required [the seller] to indemnify it”; “accepted possession of

73
jurisdictions that declined to apply section 230 immunity to strict liability
claims, Bolger stated: “We agree with Erie [Ins. Co. v. Amazon.com Inc. (4th
Cir. 2019) 925 F.3d 135] and State Farm [Fire & Cas. Co. v. Amazon.com Inc.
(W.D.Wis. 2019) 390 F.Supp.3d 964] on this issue. Bolger’s strict products
liability claims target Amazon’s role in ‘the vertical distribution of consumer
goods’ (Bay Summit [Community Assn. v. Shell Oil Co. (1996)] 51 Cal.App.4th
[762,] 773) as an ‘integral part of the overall producing and marketing
enterprise’ for the [third-party seller’s] replacement laptop battery
(Vandermark [v. Ford Motor Co. (1964)] 61 Cal.2d [256,] 262). It is based on
Amazon’s own conduct, as described above, not the content of [the third-party
seller’s] product listing. Bolger’s claims do not require a court to treat
Amazon as the speaker or publisher of content provided by [the third-party
seller]. The content of the product listing is not determinative, and it need
not be attributed to Amazon to support strict liability. Instead, Amazon’s
own involvement in the distribution of an allegedly defective product

[the seller’s] products, registered them in its inventory system, and stored
them in an Amazon warehouse awaiting sale”; “created the format for [the
seller’s] offer for sale”; and “allowed [the seller] to use a fictitious name in its
product listing.” (Bolger, supra, 53 Cal.App.5th at p. 452.) Additionally, the
product listing “does not conspicuously inform the consumer of the identity of
the third party seller or the nature of Amazon’s relationship to the sale”; the
customer purchases the product by adding it to her Amazon cart and pays
Amazon; under the FBA program, Amazon personnel retrieve the product
from an Amazon warehouse and ship it to the customer in Amazon branded
packaging (potentially together with items purchased from other sellers or
Amazon itself); the seller is not involved in the sales transaction and “does
not receive payment until Amazon chooses to remit the proceeds”; the
customer sends returns to Amazon; and third-party sellers “are prohibited
from communicating with Amazon customers except through the Amazon
website, where such interactions are anonymized.” (Id. at pp. 452–453.)

74
supports strict liability for the reasons we have already discussed.” (Bolger,
at p. 464.)
Other cases similarly distinguish claims that treat an interactive
computer service provider as a publisher from claims that do not, despite
being associated with third-party content. In Barnes, supra, 570 F.3d 1096,
after a period of failing to respond to the plaintiff’s requests to remove
indecent material her former boyfriend posted without her consent on
Yahoo.com, the company expressly promised to remove the material, then did
not do so. (Id. at pp. 1098–1099.) The Ninth Circuit concluded the plaintiff’s
cause of action for “negligent undertaking” was barred by section 230 because
it sought to hold Yahoo liable for failing to remove the offending material,
which was publishing activity.
The plaintiff’s cause of action for promissory estoppel, however, was not
barred. (Barnes, supra, 570 F.3d at p. 1109.) Although the promise
underlying this claim involved the same conduct—removing the material
from the Web site—the duty allegedly violated “springs from a contract—an
enforceable promise—not from any non-contractual conduct or capacity of the
defendant.” “Contract liability here would come not from Yahoo’s publishing
conduct, but from Yahoo’s manifest intention to be legally obligated to do
something, which happens to be removal of material from publication.” (Id.
at p. 1107.) The “outwardly manifested intention to create an expectation on
the part of another . . . generates a legal duty distinct from the conduct at
hand, be it the conduct of a publisher, of a doctor, or of an overzealous uncle.”
(Id. at p. 1108.)
Internet Brands, Inc., supra, 824 F.3d 846 provides another illustration
of the same point. There, two individuals used the defendant’s Web site, a
networking Web site for the modeling industry, to lure the plaintiff to sham

75
auditions where she was drugged and raped. (Id. at p. 848.) The plaintiff
alleged that the Web site owner had independent knowledge of the ongoing
scheme but failed to warn her or other Web site users, in violation of a duty
to warn imposed by California law, and the district court dismissed the action
as barred by section 230. (Internet Brands, Inc., at pp. 848–850.) Reversing,
the Ninth Circuit explained that the plaintiff did not seek to hold the Web
site owner liable as publisher or speaker of a third party’s posted content, for
failing to remove such content or for any conduct related to monitoring or
failing to monitor posts on the Web site. (Id. at p. 851.) Instead, the plaintiff
argued the defendant was liable for failure to warn her about information
obtained from an outside source about the scheme being perpetrated on its
Web site, which could be accomplished without altering or removing the
third-party content, for example, by posting a warning on the Web site or
emailing users. (Ibid.) Accordingly, the negligent failure to warn claim did
not seek to hold the Web site owner liable as the “ ‘publisher or speaker of
any information provided by another information content provider’ ” and
section 230 did not bar the claim. (Internet Brands, Inc., at p. 851.)
Here, Lee claims Amazon violated Proposition 65 exposing consumers
to mercury without warnings through its own conduct. The claims do not
attempt to hold Amazon responsible for third-party sellers’ content (except in
the sense that Amazon would have been able to disclaim responsibility for
providing warnings if the sellers had provided them). As we have discussed,
the claims do not require Amazon to modify or remove third-party content
but rather to provide a warning where Amazon’s own conduct makes it
subject to Health and Safety Code section 25249.6.
The Ninth Circuit cases make another point that is of critical
importance here. HomeAway.com emphasized that “[l]ike their brick-and-

76
mortar counterparts, internet companies must also comply with any number
of local regulations concerning, for example, employment, tax, or zoning” and
“allowing internet companies to claim CDA immunity under these
circumstances would risk exempting them from most local regulations
and . . . ‘create a lawless no-man’s-land on the Internet.’ ” (HomeAway.com,
supra, 918 F.3d at p. 683, quoting Roommates.com, supra, 521 F.3d at
p. 1164.) The court explained, “We have consistently eschewed an expansive
reading of [section 230] that would render unlawful conduct ‘magically . . .
lawful when [conducted] online,’ and therefore ‘giv[ing] online businesses an
unfair advantage over their real-world counterparts.’ ” (HomeAway, at
p. 683, quoting Roommates.com, at p. 1164.) In this respect, “ ‘we must be
careful not to exceed the scope of the immunity provided by Congress.’ ”
(Internet Brands, Inc., supra, 824 F.3d at p. 853, quoting Roommate.com, at
p. 1164, fn. 15.)
If a skin-lightening cream is sold in a brick-and-mortar drug store that
was aware the product contained mercury, there is no question that retail
seller would have some obligation to provide Proposition 65 warnings—
depending, of course, on whether entities further up the distribution chain
had provided warnings for the products and, if not, could be held to account.
Nothing in the text or purposes of the CDA suggests it should be interpreted
to insulate Amazon from responsibilities under Proposition 65 that would
apply to a brick-and-mortar purveyor of the same product.
Not only would such an interpretation give Amazon a competitive
advantage unintended by Congress in enacting the CDA, but it would be
inimical to the purposes of Proposition 65. Amazon makes it possible for
sellers who might not be able to place their products in traditional retail
stores to reach a vast audience of potential customers. (E.g., Bolger, supra,

77
53 Cal.App.5th at p. 453 [“The Amazon website . . . enables manufacturers
and sellers who have little presence in the United States to sell products to
customers here”].) The evidence in this case indicates that mercury-
containing skin-lightening products are overwhelmingly likely to have been
manufactured outside the United States—unsurprisingly, as FDA
regulations prohibit use of mercury as a skin-lightening agent in cosmetics.
(21 C.F.R. § 700.13.) This makes it all the more likely Amazon may be the
only business that can readily be compelled to provide a Proposition 65
warning for these products. (See 2016 FSOR, supra, p. 55 [discussing
impracticality of enforcing warning requirement against foreign entity
without agent for service of process in United States]; Bolger, supra,
53 Cal.App.5th at p. 453 [noting as first factor supporting application of strict
liability doctrine to Amazon that it “may be the only member of the
distribution chain reasonably available to an injured plaintiff who purchases
a product on its website”].) Amazon is thus making available to consumers,
and profiting from sales of, products that clearly require Proposition 65
warnings, yet are likely to have been manufactured and distributed by
entities beyond the reach of reasonable enforcement efforts. Insulating
Amazon from liability for its own Proposition 65 obligations in these
circumstances would be anomalous.
Proposition 65, as we have said, “ ‘is a remedial law, designed to protect
the public’ ” which must be construed “ ‘broadly to accomplish that protective
purpose.’ ” (Center for Self-Improvement & Community Development v.
Lennar Corp., supra, 173 Cal.App.4th at pp. 1550–1551, quoting People ex rel.
Lungren v. Superior Court, supra, 14 Cal.4th at p. 314.) Moreover, states’
“police powers to protect the health and safety of their citizens . . . are
‘primarily, and historically, . . . matter[s] of local concern.’ ” (Medtronic, Inc.

78
v. Lohr (1996) 518 U.S. 470, 485.) The United States Supreme Court has
explained that “[w]hen addressing questions of express or implied pre-
emption, we begin our analysis ‘with the assumption that the historic police
powers of the States [are] not to be superseded by the Federal Act unless that
was the clear and manifest purpose of Congress.’ [Citation].” (Altria Group,
Inc. v. Good (2008) 555 U.S. 70, 77.) The “strong presumption against
displacement of state law . . . applies not only to the existence, but also to the
extent, of federal preemption. [Citation.] Because of it, ‘courts should
narrowly interpret the scope of Congress’s “intended invalidation of state
law” whenever possible.’ [Citation].” (Brown v. Mortensen (2011) 51 Cal.4th
1052, 1064.)
As the Ninth Circuit has explained, Congress intended “to preserve the
free-flowing nature of Internet speech and commerce without unduly
prejudicing the enforcement of other important state and federal laws. When
Congress passed section 230 it didn’t intend to prevent the enforcement of all
laws online; rather, it sought to encourage interactive computer services that
provide users neutral tools to post content online to police that content
without fear that through their ‘good samaritan . . . screening of offensive
material,’ [citation], they would become liable for every single message posted
by third parties on their website.” (Roommates.com, supra, 521 F.3d at
p. 1175, quoting § 230(c).)
The text of section 230(e)(3) is clear that state laws inconsistent with
section 230 are preempted while those consistent with section 230 are not
preempted. Proposition 65’s warning requirement is an exercise of state
authority to protect the public that imposes obligations on any individual who
exposes another to a listed chemical. Proposition 65 is not inconsistent with
the CDA because imposing liability on Amazon for failing to comply with its

79
own, independent obligations under Proposition 65, does not require treating
Amazon as the publisher or speaker of third-party sellers’ content.
Accordingly, if Lee can establish all the elements of a violation of Proposition
65, section 230 does not immunize Amazon from liability.
DISPOSITION
The judgment is reversed and the matter is remanded for further
proceedings in accordance with the views expressed in this opinion.
On remand, if Lee is able to establish all the elements of his claims as
to the products purchased from Amazon and tested for mercury content, the
trial court shall determine whether the products with different ASINs
identified in Lee’s pretrial brief as among the 11 products at issue were in
fact the same products as the ones for which samples were tested, and shall
determine penalties in accordance with Health and Safety Code section
25249.7 for any violations of Proposition 65 established.

80
 _________________________
Kline, J.*

We concur:

_________________________
Richman, Acting P.J.

_________________________
Stewart, J.

Lee v. Amazon (A158275)

*Assigned by the Chief Justice pursuant to article VI, section 6 of the
California Constitution.

81
Trial Court: Alameda County Superior Court

Trial Judge: Hon. Robert McGuiness

Attorney for Plaintiff and Appellant Law Office of Jonathan Weissglass
Larry Lee: Jonathan Weissglass

Greenfire Law
Rachel S. Doughty
Jessica L. Blome

Attorneys for Amicus Curiae on behalf Rob Bonta
of Plaintiff and Appellant: Attorney General of California
Dennis A. Ragen
Roxanne Carter
Deputy Attorneys General

Attorneys for Amicus Curiae Danielle R. Fugere
As you Sow on behalf of Plaintiff Chelsea J. Linsley
Appellant:

Attorneys for Amicus Curiae Altshuler Berzon
Center For Food Safety on behalf Barbara J. Chisholm
of Plaintiff and Appellant: P. Casey Pitts

Attorneys for Amici Curiae Black Environmental Law Clinic
Women for Wellness and the Mercury Mills Legal Clinic at Stanford Law School
Policy Project/Tides Center on behalf Deborah A. Sivas
of Plaintiff and Appellant: Molly Loughney Melius

Attorneys for Defendant Doll Amir & Eley
and Respondent Amazon.com, Inc.: Gregory L. Doll
Brett H. Oberst
Jamie O. Kendall
Lloyd Vu

Attorneys for Amicus Curiae Law Office of Fred. J. Hiestand
The Civil Justice Association of Fred J. Hiestand
California on behalf of Defendant
and Respondent:

82