— Five major cigarette manufacturing companies and three Washington businesses (hereinafter Companies) brought an action for declaratory judgment and injunctive relief in Thurston County Superior Court against the State of Washington, arguing that a regulation adopted by the Department of Labor and Industries (Department) regulating smoking in private workplaces was invalidly promulgated. The trial court upheld the Department’s regulation. The Companies thereafter appealed the decision of the Superior Court to the Court of Appeals, Division Two, which, in turn, certified the case to this court for direct review. We granted review and now affirm the trial court.
On November 3, 1993, the Department filed proposed indoor air quality regulations. One of the proposed regulations was aimed at eliminating environmental tobacco smoke (ETS)1 exposures in private workplaces. Following that filing the Department received extensive written comments on their proposal and conducted six public hearings. The Companies presented testimony at the hearings and submitted voluminous written materials concerning the alleged adverse health effects of workplace ETS exposures. Although the Department decided to not promulgate the other proposed indoor air quality regulations,2 the ETS *416regulation was issued in final form on March 16, 1994— unchanged from its proposed form in any respect material to this case. An accompanying Concise Explanatory Statement (CES) indicated why the Department adopted the regulation.
On June 23, 1994, the Joint Administrative Rules Review Committee (JARRC), comprised equally of some state senators and representatives, reviewed the ETS regulation and by a two-thirds majority vote recommended its suspension because it “goes beyond the Department’s statutory authority.” Clerk’s Papers (CP) at 123. After another public hearing the Department rejected JARRC’s recommendation.
The Companies then filed an action for declaratory judgment and injunctive relief in Thurston County Superior Court. The filing was soon followed by their motion for summary judgment. They asserted in their motion, among other things, that the Department violated the Washington Administrative Procedure Act (APA), RCW 34.05, and also failed to meet the two-part “significant risk” test enunciated in Industrial Union Department, AFL-CIO v. American Petroleum Institute, 448 U.S. 607, 100 S. Ct. 2844, 65 L. Ed. 2d 1010 (1980) (plurality opinion) [hereinafter Benzene] that the Companies alleged was required under the Washington Industrial Safety and Health Act (WISHA), RCW 49.17. The trial court denied the motion. The Companies then renewed the motion, indicating that they had new evidence of the Department’s alleged failure to comply with Benzene. They also moved to exclude any supplemental trial testimony by Department officials. The trial court denied these motions.
A bench trial was held in early 1996. At trial, the Department submitted its CES, which stated that its risk assessment was based upon an Environmental Protection Agency (EPA) report, as well as “reports issued by the Surgeon General of the United States, the National Research *417Council, and other studies.” AR 58: 34,449.3 The Department’s then-director, Mark Brown, testified at trial and identified a National Institute of Occupational Safety and Health report, as well as a joint report from the Fred Hutchinson Cancer Center and the Washington Department of Health, as also forming a basis for the Department’s decision to promulgate the ETS regulation. Brown admitted that the Department did not run an independent statistical analysis on these reports, nor set out its own threshold for “significant risk.” Report of Proceedings (RP) at 157.
The trial court upheld the ETS regulation in an oral ruling, following that with an order on July 22, 1996, in which it dismissed the Companies’ petition. The Companies appealed to the Court of Appeals, Division Two, which certified the appeal to this court for direct review. The certification was accepted.4
ANALYSIS
1. Was the Department required under the APA to explain its complete rationale for the ETS regulation in the administrative record?
The Companies’ contend that the trial court erred in concluding that the Department was not required to confine its rationale for the ETS regulation to materials within the administrative record. The Department responds that it satisfied the then-minimal requirements for a CES, and that, in any event, the regulation’s rationale was adequately explained through a combination of both the CES and supplemental trial testimony.
*418We note at the outset of our discussion of this issue, that the APA’s then-existing requirement for a CES must be distinguished from the requirement for a rule-making file. It is undisputed that the size of the record in this case, which fills 15 boxes,5 is quite irrelevant to the question of whether the Department fulfilled its statutory obligation to explain the ETS regulation’s rationale. One administrative law professor has written that “the record is merely a compilation of the material considered by the agency in the rulemaking. It can be likened to a big cardboard box into which copies of things considered are thrown.” William Funk, Rationality Review of State Administrative Rulemaking, 43 Admin. L. Rev. 147, 166 (1991). For our purposes the essential content of the voluminous rule-making file in this case are the few pages that comprise the CES.
At the time the ETS regulation was adopted, the statutory requirement for a CES, RCW 34.05.355, repealed by Laws of 1995, ch. 403, § 305 [hereinafter RCW 34.05.355 (1992)3, read as follows:
(1) At the time it files an adopted rule with the code reviser or within thirty days thereafter, an agency shall place into the rule-making file maintained under RCW 34.05.370 a concise explanatory statement about the rule, identifying (a) the agency’s reasons for adopting the rule, and (b) a description of any difference between the text of the proposed rule as published in the register and the text of the rule as adopted, other than editing changes, stating the reasons for change.
Appellants strain to import a federal standard of review into this state APA case. With regard to the CES requirement they try to read into it the requirements imposed under federal administrative law cases by taking issue with the fact that the trial court admitted the testimony of Department witnesses to supplement the rationale provided *419in the CES.6 However, the practice of admitting such testimony was clearly envisioned at the time of the APA’s adoption. Indeed, Professor William Andersen, a member of the task force that proposed the APA to the Legislature, lamented the absence of a stricter judicial review standard:
The Model Act wisely included a provision that limited justification of rules on judicial review to reasons contained in the agency’s concise general statement. The purpose of such a restriction is to ensure that reasons and justifications were part of the agency deliberative process and not the post hoc rationalizations of agency lawyers or judges. . . .
. . . Unfortunately, such a provision was not proposed for inclusion in the new Act [the Washington APA]. It is to be hoped that the legislature will correct this oversight at an early date ....
William R. Andersen, The 1988 Washington Administrative Procedure Act—An Introduction, 64 Wash. L. Rev. 781, 803-04 (1989) (emphasis in second paragraph added) (footnotes omitted). In fact, the APA specifically provides that the trial court is permitted to take additional evidence where needed to “decide disputed issues regarding . . . [u]nlawfulness of procedure or of decision-making process.” RCW 34.05.562(l)(b).
We believe the Companies misunderstand Neah Bay Chamber of Commerce v. Department of Fisheries, 119 Wn.2d 464, 832 P.2d 1310 (1992), which they cite as authority forbidding what this court and statute expressly allow. In Neah Bay we indicated that while “additional evidence of an agency’s reasoning and the background materials relied upon may be presented on review, such evidence is *420only admissible to explain the agency’s decision at the time.” Neah Bay, 119 Wn.2d at 474-75 (citation omitted). Moreover, a distinguishing fact in Neah Bay cannot be stressed enough: there the Department of Fisheries had failed to present any administrative record as required by the APA. “Because there was no record presented of what actually went into the Department’s regulations ... it is impossible to say whether they were rational or irrational.” Neah Bay, 119 Wn.2d at 475. Instead, the trial court “relied solely on deposition and other testimony of experts which was not contemporaneous with the rule-making process.” Neah Bay, 119 Wn.2d at 475. Although admissible, this was not enough, because it could obviously only “supplement, not replace, the administrative record.” Neah Bay, 119 Wn.2d at 475.
The Companies also rely heavily upon Inland Foundry Co. v. Spokane County Air Pollution Control Authority, 82 Wn. App. 67, 915 P.2d 537 (1996), review denied, 131 Wn.2d 1025, 937 P.2d 1101 (1997), for the blanket proposition that an agency must, under the APA, “provide a clear explanation of its reasons for issuing a workplace standard which demonstrates that it considered the proper legal factors and that it rationally reviewed and analyzed the pertinent evidence.” Appellants’ Br. at 12. This is a misinterpretation of the holding. Inland Foundry involved a municipal corporation, which was “not governed by RCW 34.05-.370(1)”—the APA requirement for maintaining a rule-making file. Inland Foundry, 82 Wn. App. at 71 n.5. However, in promulgating regulations it was required to make “special reference to effects on health, economic and social factors, and physical effects on property.” Inland Foundry, 82 Wn. App. at 70 (quoting RCW 70.94.151). This it did not do, instead failing “to make any rule-making information available.” Inland Foundry, 82 Wn. App. at 71 n.5 (emphasis added). Inland Foundry is simply too factually dissimilar to the instant case to stand for the proposition that the Companies cite it for. In fact, as in Neah Bay, the court in Inland Foundry did write that “post-enactment support may supplement an administrative record,” al*421though, of course, “it cannot replace it.” Inland Foundry, 82 Wn. App. at 71 n.5.
The Companies overlook the following language from the APA as it existed at the time the ETS regulation was adopted: “Upon the request of any interested person within thirty days after adoption of a rule, the agency shall issue a concise statement of the principal reasons for overruling the considerations urged against its adoption.” RCW 34.05.355(2) (1992). The Companies did not make this request in the period provided. Rather, they sat on their rights when they had the opportunity to assert them and essentially now fault the Department for not answering a question that it was never asked.
In effect, what the Companies seem to be arguing for is an application of the APA as it currently exists to a rule promulgated prior to some “regulatory reform” changes in the APA. It was only following the adoption of the ETS regulation in 1994 that the language of the APA was amended to provide that before an agency adopts a final rule it shall summarize all comments received by the agency and respond to the comments by content or subject matter, “indicating how the final rule reflects agency consideration of the comments, or why it fails to do so.” Laws of 1994, ch. 249, § 7(6). The Legislature even expressly provided that this change “applies prospectively only and not retroactively.” Laws of 1994, ch. 249, § 36. Thus no retroactive application is possible. Regardless, why would this change have been made if, to follow the Companies’ argument, it was redundant to that which was already required'? “It is presumed that the legislature does not deliberately engage in unnecessary or meaningless acts.” Knowles v. Holly, 82 Wn.2d 694, 704, 513 P.2d 18 (1973) (citing Roza Irrigation Dist. v. State, 80 Wn.2d 633, 497 P.2d 166 (1972)). Moreover, even today, as was true in 1994, “the official agency rule-making file need not be the exclusive basis for agency action on that rule.” RCW 34.05.370(4).
Even the Companies do not argue that the Department’s *422witnesses offered explanations for the ETS regulation beyond explaining why they made the “decision at the time.” Neah Bay, 119 Wn.2d 475 (emphasis added). The Department’s witnesses did not offer, for example, truly “post hoc” evidence such as studies reported after the regulation was adopted. Accordingly, even assuming that the Companies are correct and the CES was not adequate to support the ETS regulation, admitting testimony to establish the regulation’s basis was obviously permissible. That brings us to the next step: “[T]he general rule is that a superior court’s findings are not relevant in appellate review of an agency action; however, where the superior court takes additional evidence . . . the appellate court will look to the superior court record.” Seattle Bldg. & Constr. Trades Council v. Apprenticeship & Training Council, 129 Wn.2d 787, 799, 920 P.2d 581 (1996) (citation omitted).
In sum, we conclude that the Department was not required at the time of the ETS regulation’s adoption to explain its complete rationale in the administrative record, and that the testimony of the Department’s officials was properly admitted to supplement the CES.
2. Did the Department satisfy its statutory requirements under the WISHA in promulgating the ETS regulation?
The Companies argue next that the trial court erred in concluding that the Department had satisfied its statutory obligations under the WISHA in promulgating the ETS regulation. Under WISHA, as it existed at the time the ETS regulation was adopted, the Department had the authority to promulgate “safety and health standards” that were “reasonably necessary or appropriate to provide safe or healthful employment and places of employment.” RCW 49.17.020(6) (1992). The Companies admit that the “reasonably necessary or appropriate” requirement has not been addressed by the Washington courts, but note that “safety and health standards” are defined identically in the federal Occupational and Safety Health Act (OSH *423Act). Appellants’ Br. at 16 (citing 29 USC § 652(8)). Accordingly, the Companies urge us to rely upon the two-part “significant risk” test adopted in a plurality opinion by the United States Supreme Court in Benzene.
In Benzene the Court struck down an Occupational Safety and Health Administration (OSHA) standard limiting occupational exposure to benzene, holding that under the OSH Act before any “health and safety standard” was promulgated it must be determined that, first, there is “a significant risk of material health impairment” and that, second, the regulation is “reasonably necessary and appropriate to remedy” it.7 Benzene, 448 U.S. at 639. Then-Justice Rehnquist concurred in the result only, reasoning that the power to promulgate such a standard never should have been delegated from Congress to the OHSA in the first place. Benzene, 448 U.S. at 687 (Rehnquist, J., concurring in the result) (“[H]ard choices . . . must be made by the elected representatives of the people.”) (emphasis added)). Thus he did not pass on the two-part “significant risk” test adopted by four of his colleagues. Indeed, quite contrary to the Companies’ assertion, it appears that a majority of the Court has never adopted this test, but has instead merely noted that OSHA itself has adopted it. See American Textile Mfrs. Inst., Inc. v. Donovan, 452 U.S. 490, 505 n.25, 101 S. Ct. 2478, 69 L. Ed. 2d 185 (1981). Ultimately, however, in light of our disposition of this case the question of the “significant risk” test’s acceptance by the Court and other courts is simply irrelevant.
Standards adopted under the WISHA “shall equal or exceed” the OSH Act standards. RCW 49.17.010 (emphasis added). They must be “at least as effective as those adopted *424or recognized” under the OSH Act. RCW 49.17.050(2) (emphasis added). Thus, they can be more protective, although not less, of worker safety than rules promulgated under the OSH Act. However, the OSHA has not even adopted any ETS regulations. Thus there is no relevant federal standard to “equal or exceed.” RCW 49.17.010. Accordingly, the Companies citation to wholly unrelated federal OSH Act cases provides us little guidance. Moreover, even if the word “exceed” could be read out of the WISHA, and the standard for worker protections was just “equal” under both statutes, “[i]t is well settled that the Supreme Court’s construction of a similarly worded federal statute, although often persuasive, ‘is not controlling in our interpretation of a state statute.’ ” Hoffer v. State, 113 Wn.2d 148, 151, 776 P.2d 963 (1989) (quoting State v. Gore, 101 Wn.2d 481, 487, 681 P.2d 227, 39 A.L.R.4th 975 (1984)) (additional citations omitted). Thus we are by no means bound by the Benzene test.
Further distinguishing Benzene is that the liquid regulated there “is a familiar and important commodity. . . . used in manufacturing a variety of products including motor fuels . . . solvents, detergents, pesticides, and other organic chemicals.” Benzene, 448 U.S. at 615. Roughly “11 billion pounds of benzene were produced in the United States in 1976,” and the Court noted that “[bjecause of benzene’s importance to the economy, no one has ever suggested that it would be feasible to eliminate its use entirely, or to try to limit exposures to the small amounts that are omnipresent.”8 Benzene, 448 U.S. at 615, 637. In contrast, as the Department notes, “[t]obacco smoke is not needed to produce any product or service by any business in this state.” Resp’ts’ Br. at 30. Even the Companies cannot argue that there is any benefit to ETS. “[UJnlike benzene, ETS is not indispensable to any job and, therefore, there is less reason to avoid banning it completely in the workplace.” Fogle v. H&G Restaurant, Inc., 337 Md. 441, 654 A.2d 449, 458 n.8 (1995).
*425Even assuming that the Benzene test was applied,
imposing a burden on the Agency of demonstrating a significant risk of harm will not strip it of its ability to regulate carcinogens, nor will it require the Agency to wait for deaths to occur before taking any action. First, the requirement that a “significant” risk be identified is not a mathematical straitjacket. It is the Agency’s responsibility to determine, in the first instance, what it considers to be a “significant” risk. . . .
Second, OSHA is not required to support its finding that a significant risk exists with anything approaching scientific certainty. Although the Agency’s findings must be supported by substantial evidence ... so long as they are supported by a body of reputable scientific thought, the Agency is free to use conservative assumptions in interpreting the data with respect to carcinogens, risking error on the side of overprotection rather than underprotection.
Benzene, 448 U.S. at 655-56 (emphasis added) (footnote omitted). The Benzene plurality noted that “[w]e express no opinion on what . . . factual determinations would warrant a conclusion that significant risks are present which make promulgation of a new standard reasonably necessary or appropriate.” Benzene, 448 U.S. at 659. It did, however, opine that a fatality risk of one in a billion “clearly” would not he significant, while a risk of one in a thousand “might” be. Benzene, 448 U.S. at 655. The Court apparently accepted industry testimony that “current exposure levels [to benzene] would cause at most two deaths out of. . . 30,000 workers every six years.” Benzene, 448 U.S. at 654.
Under the WISHA, the Department must base workplace exposure standards upon “the best available evidence.” RCW 49.17.050(4). Here the Department stated in its CES that it based its risk assessment upon an EPA report, as well as “reports issued by the Surgeon General of the United States, the National Research Council, and other studies.” AR 58: 34,449. In his testimony the Department’s then-director, Mark Brown, also identified a National *426Institute of Occupational Safety and Health (NIOSH) report, as well as a joint report from the Fred Hutchinson Cancer Center and the Washington Department of Health, as contributing to the decision to promulgate the ETS regulation. Brown conceded that the Department did not run an independent statistical analysis on these reports nor set out its own threshold for significant risk. He explained that “[w]e wouldn’t want to waste our time and money duplicating the effort of another public agency.” RP at 115. Choosing to not “reinvent the wheel” and instead relying upon existing ETS studies that are directly on point appears to us to be a reasonable decision, and the Companies cannot point to a case explaining why the Department should not be able to make it.9 After all, to use an example, assuming that ETS is deleterious to the healthy workers in one state it would defy logic to argue that it does not have the same effect in another.
In contrast to the two deaths every six years that were estimated to result in the absence of the regulation at issue in Benzene, the 1992 EPA report relied upon by the Department, Respiratory Health Effects of Passive Smoking: Lung Cancer and Other Disorders, quantifies risk and estimates that ETS causes 3,000 lung cancer deaths annually among United States nonsmokers based on data from 11 epidemiological studies of women who never smoked but were married to smoking spouses. The report notes that “ [workplace *427ETS levels are generally comparable with home ETS levels,” with an estimated 2,200 deaths due to nonspousal exposures. AR 49: 30,275. It “does not develop an analysis of . . . the heart disease data.” AR 49: 30,267. Although the report does not clearly recommend government regulation of smoking, Maryland relied upon it in adopting its own regulation relating to ETS. Fogle, 654 A.2d at 453.
The Companies cite a recent case in which a United States District Court in North Carolina “vacated” portions of the EPA report due to what it found to be procedural and methodological flaws. Flue-Cured Tobacco Coop. Stabilization Corp. v. United States Envtl. Protection Agency, 4 F. Supp. 2d 435 (M.D.N.C. 1998), appeal filed, No. 6:93CV370 (4th Cir. Sept. 15, 1998). This decision is on appeal. However, even if the District Court is correct, and the EPA report is flawed, the Department rule-making built atop it four years earlier would not, as appellants apparently suggest, collapse like a house of cards. Regulations are not that tenuous. The standard under our state’s APA is whether the choice to rely upon the EPA report was rational at the time it was made. “The court must scrutinize the record to determine if the result was reached through a process of reason, not whether the result was itself reasonable in the judgment of the court.” Neah Bay, 119 Wn.2d at 474 (emphasis added); see also Flue-Cured Tobacco Coop., 4 F. Supp. 2d at 455 (“A risk assessment, by its very nature, is not a final determination about the health effects of a substance but is instead an assessment that makes the best judgments possible based upon the available evidence.”) (emphasis added) (citation omitted). Accordingly, this federal case is not dispositive. Regardless, then-Director Brown testified that the EPA report is not the sine qua non of the support for the ETS regulation: “In the single absence of the EPA report, I think there’s plenty left to support a rational decision maker reaching the decision and conclusion I made with EPA as part of the foundation.” RP at 150. Without question, however, the EPA report would appear to be the firmest basis for the *428regulation among the reports cited in the CES and by then-Director Brown in his testimony.
The 1991 NIOSH report, Environmental Tobacco Smoke in the Workplace: Lung Cancer and Other Health Effects, summarized studies exploring the link between ETS, cancer and heart disease, and concluded that “ETS poses an increased risk of lung cancer and possibly heart disease to occupationally exposed workers.” AR 49: 30,077. Although the report did not quantify the significance of the risk, it recommended that tobacco use either be eliminated in the workplace or that smoking occur only in enclosed, separately ventilated areas.
The 1990 joint report from the Fred Hutchinson Cancer Research Center and the Washington Department of Health, Smoking in Washington State: Status of the Problem and Recommendations for Intervention, offers what the report acknowledges is only “a crude and possibly conservative estimate of excess mortality from passive cigarette smoke exposure” of 89.5 lung cancer deaths in Washington. AR 53: 32,524. This figure is not broken down between homes and workplaces. However, it does appear to be quite rational for the Department to conclude, as the report indicates, that “a large percentage of the 89.5 lung cancer deaths in Washington per year would be work-related.” Resp’ts’ Br. at 40-41.
The 1986 National Research Council, Environmental Tobacco Smoke: Measuring Exposures and Assessing Health Effects, surveyed studies and found that “[t]he best estimate, allowing for reasonable misclassification, is that the adjusted risk of lung cancer is increased about 25% . . . in nonsmokers married to smokers compared with nonsmokers married to nonsmokers.” AR 57: 34,164. No firm conclusions could be drawn about the risk that ETS might pose to the heart. Moreover, because “[o]nly studies that assess exposures under experimental conditions or in the home are included” in the report, the implications of ETS for the workplace environment were not subject to any statistical risk discussion. AR 57: 33,945.
*429The 1986 Surgeon General’s report, The Health Consequences of Involuntary Smoking, reviewed studies conducted on the health consequences of ETS. Although it concludes that “[i]nvoluntary smoking is a cause of disease, including lung cancer, in healthy nonsmokers” (AR 52: 32,173) it adopts no statistical measure of risk itself: “[Additional data on the distribution of smokers in the nonsmokers’ environment, as well as the distribution of ETS levels in that environment, are needed in order to characterize the actual ETS exposure of the U.S. population.” AR 52: 32,301 (emphasis added).
While none of the reports just described advocated the type of ETS regulation that is at issue here, they clearly provided evidence from which a reasonable conclusion could be drawn that such a regulation is necessary to protect worker health. Because it encompassed the most current data the EPA report appears to have been the “the best available evidence.” RCW 49.17.050(4). How can it be reconciled, however, with the Companies’ position? The United States Supreme Court has written in another OSH Act case that “[t]he reviewing court must take into account contradictory evidence in the record, but ‘the possibility of drawing inconsistent conclusions from the evidence does not prevent an administrative agency’s finding from being supported by substantial evidence.’ ” American Textile Mfrs. Inst., 452 U.S. at 523 (quoting Consolo v. Federal Maritime Comm’n, 383 U.S. 607, 620, 86 S. Ct. 1018, 16 L. Ed. 2d 131 (1966)). Similarly, the District of Columbia Circuit Court of Appeals has written that “the court must not second-guess the particular way the agency chooses to weigh the conflicting evidence or resolve the dispute.” United Steelworkers of Am. v. Marshall, 647 F.2d 1189, 1263 (D.C. Cir. 1980); see also Fogle, 654 A.2d at 458 (“We do not second guess the judgmental basis upon which the agency chose to weigh the conflicting evidence.”). We have held that “ [substitution of our judgment for that of the administrative agency in factual matters is not authorized by the APA and . . . we will not try facts de novo on *430review.” Franklin County Sheriff’s Office v. Sellers, 97 Wn.2d 317, 325, 646 P.2d 113 (1982).
The fact that the EPA report “included no workplace studies,” Appellants’ Reply Br. at 23, is not determinative. The trial judge noted that the evidence
was sufficient to justify the Department’s rationale . . . that the link between ETS and spousal studies would be at least the same, if not greater than the ETS exposure in the workplace, given the probability that there would be more smokers in the workplace than there would be generated by one particular spouse and that the period of time would certainly be as much on general terms of exposure as would be experienced in the home, and the ability to be separate from one conducting a smoking activity would be perhaps in certain occasions, more limited than that available to a non-smoker in the home.
And, regardless, ... I don’t know whether or not the Department’s view or the view of the studies relied upon by the Department is ultimately the best. It’s not for me to make that judgment.
RP at 822-23 (emphasis added).
The Companies cite “two major spousal studies,” whose lead authors were Ross Brownson and Heather Stockwell, as comprising some of the evidence best supporting their position. See Appellants’ Br. at 54. However, even these studies contain sufficient support for the Department’s position, with the Brownson study also being included as evidence “in the Department’s portion of the rulemaking file,” Resp’ts’ Br. at 59 (emphasis added), to make them, at best, ambiguously supportive of the Companies’ position. The concluding sentence of Brownson’s study, for example, reads as follows: “The proliferation of federal, state, and local regulations that restrict smoking in public places and work sites is well founded.” AR 57: 34,259 (footnote omitted); Ross C. Brownson et al., Passive Smoking and Lung Cancer in Nonsmoking Women, 82 Am. J. Pub. Health 1525, 1529 (1992) (footnote omitted). It is difficult to even characterize such evidence as “conflicting,” let alone ques*431tion the Department for resolving any conflict in the manner it did.10 As the trial judge noted: “There is not that quantum of evidence which results in the necessary conclusion that the science is more probably than not the way the plaintiffs argue it as opposed to the department.” RP at 823. The only question then becomes whether the Department was required to quantify, in its CES, the risk posed by ETS. In addressing this particular question it is appropriate to turn to guidance from another state court confronted with it:
[TJhere was a sufficient foundation in the record to support the Commissioner’s conclusion that, on the present state of evidence, it is impossible to set a safe level of ETS because no such safe or threshold level is now known at which ETS would not pose a health hazard to Maryland employees, or which can be easily ascertained through current scientific knowledge; and, if one could be ascertained, it would be so low that it would be meaningless from a regulatory perspective.
Fogle, 654 A.2d at 458. It is significant, as the Department asserts, the Companies do not cite a single case in which a state has actually quantified “significant risk” under a state plan similar to the OSH Act.
Under the WISHA, in language mirroring that of the OSH Act, the Department’s director was required to establish an ETS regulation “which most adequately assures *432. . . that no employee will suffer material impairment of health or functional capacity even if such employee has regular exposure to the hazard dealt with by such standard for the period of his working life.” RCW 49.17.050(4) (emphasis added). We agree with the dissent in Benzene that the “significant risk” test in the plurality opinion there “renders utterly superfluous” this standard-setting language, and that “it is an odd canon of construction that would insert in a vague and general definitional clause a threshold requirement that overcomes the specific language placed in a standard-setting provision.” Benzene, 448 U.S. at 709 (Marshall, J., dissenting); see also Knowles, 82 Wn.2d at 702 (“[W]here there is a conflict between one statutory provision which deals with a subject in a general way and another which deals with the same subject in a specific manner, the latter will prevail.”) (citing State ex rel. Phillips v. Liquor Control Bd., 59 Wn.2d 565, 369 P.2d 844 (1962)). Accordingly, while Benzene provides a useful backdrop against which to examine this case, we find that its two-part “significant risk” formulation raises more questions than it provides answers, with its amorphousness creating the risk that judges could use it to impose their own policy predilections, and we do not choose to adopt it for purposes of interpreting WISHA. See Hoffer, 113 Wn.2d at 151. We agree that “a court is not permitted to distort a statute’s meaning in order to make it conform with the Justices’ own views of sound social policy.” Benzene, 448 U.S. at 688 (Marshall, J., dissenting) (citing Tennessee Valley Auth. v. Hill, 437 U.S. 153, 98 S. Ct. 2279, 57 L. Ed. 2d 117 (1978)). Whether regulations are reasonable or appropriate is a question for the fact finder to determine on a case-by-case basis, subject to only limited review by this court. We cannot legislate in order to add to what the Legislature has already said. See Tapper v. Employment Sec. Dep’t, 122 Wn.2d 397, 405-06, 858 P.2d 494 (1993). Again, the standard is that “[t]he court must scrutinize the record to determine if the result was reached through a process of reason, not whether the result was itself reasonable in the judgment of the court.” Neah Bay, 119 Wn.2d at *433474 (emphasis added). In any event, common sense would compel a conclusion that it would generally not be “reasonably necessary or appropriate” to regulate an insignificant risk, thus defeating the overwrought hypothetical involving a governmental perfume ban that the Companies offer to illustrate the supposed perils of the Department’s regulatory authority. See Appellant’s Reply Br. at 15.
It is important to note that the ETS regulation does not entirely ban smoking in private workplaces. Were it to do so it would present a different case than this one. No restrictions, for example, are imposed upon smoking in outdoor workplaces. Furthermore, indoor smoking may still occur if the workplace provides a separately ventilated space for it. WAC 296-62-12005. Ironically, among the materials in the Department’s section of the rule-making file is a report from one of the Companies, R.J. Reynolds, stressing the ease with which such a smoking lounge can be established. The report, Developing a Smoking Lounge, notes that “[developing a smoking lounge need not be expensive or difficult. In many cases, existing rooms or offices can be converted into a smoking lounge with very little time, effort or money.” AR 49: 30,086. This seems to be a “feasible” accommodation,11 RCW 49.17.050(4), and is one recommended by the NIOSH report relied upon by the Department. See AR 49: 30,078. Accordingly, it is only when an employer is unwilling to spend “very little time, effort or money” to protect nonsmoking workers from entirely unnecessary and, thus, entirely avoidable, ETS exposure that smoking is banned indoors.12 It is curious that the Companies fail to mention this. Instead they create the impres*434sion that the ETS regulation is “a complete ban.” Appellants’ Br. at 31.
To be sure, the CES was no model of comprehensiveness. However, it seems clear to us from the CES and from the testimony of the Department’s witnesses that ETS was identified as posing a significant risk to Washington workers, and that even an agency bound by the exacting Benzene test “is not required to support its finding that a significant risk exists with anything approaching scientific certainty.” Benzene, 448 U.S. at 656. The National Research Council report examined the question of whether “there is a threshold dose of cigarette smoke exposure below which there is no increase in risk,” and determined that “[bjiological theory and current evidence on low-dose exposure to carcinogens do not provide evidence for such a threshold, and it is generally thought that one is unlikely.” AR 57: 34,141 (citation omitted). The industrial hygienist who “was the person primarily responsible for advising the Department” on the ETS regulation declared that he relied upon this conclusion in not establishing a threshold. CP at 1622. Recall that “risking error on the side of overprotection rather than underprotection” is permissible even under Benzene. Benzene, 448 U.S. at 656. Accordingly, we find that no violation of the WISHA, an act that can be more protective of worker health than the OSH Act, occurred.
In sum, we conclude that the Department satisfied its statutory requirements under the WISHA in promulgating the ETS regulation to address an apparently significant, and wholly unnecessary, risk to worker health.
3. Could the Department’s decision to promulgate the *435ETS regulation have conceivably been the product of a rational decision maker?
We now turn to a final argument advanced by the Companies, namely that the trial court erred in finding that the ETS regulation was the product of a rational decision maker. It is of no consequence that the ETS regulation was adopted in a less than ideal fashion. Under the APA as it existed at the time the regulation was adopted the question was, instead, whether the regulation “could not conceivably have been the product of a rational decision-maker.” RCW 34.05.570(2)(c) (1992). Both parties agree that the resolution of this question turns upon Neah Bay:
The court’s task is to determine if a given regulation is reasonable without substituting this court’s judgment for that of the agency. First, the court inquires if the agency’s explanation of its own rule is clear. Second, the court must ask if the agency utilized the appropriate statutory framework, whether it used correct factors in deciding the rule, and if it avoided improper factors. Third, the court must decide if a decision-maker could have reached the conclusion reached by the agency (taking the foregoing into account) by some reasonable process.
Neah Bay, 119 Wn.2d at 473-74 (emphasis added). As for the first part of this three-part test, the ETS rule itself is clear, although the explanation for it is hardly exhaustive in its detail. However, this court will even “ ‘uphold a decision of less than ideal clarity if the agency’s path may reasonably be discerned.’ ” Neah Bay, 119 Wn.2d at 471 (quoting approvingly from Motor Vehicle Mfrs. Ass’n of U.S., Inc. v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43, 103 S. Ct. 2856, 77 L. Ed. 2d 443 (1983) (hereinafter State Farm). “It begins with the agency’s explanation . . . and then decides if the agency’s reasoning is plausible.” Neah Bay, 119 Wn.2d at 471. Under the second and third parts of the test we determine whether the Department could have promulgated this rule under the WISHA by “some reasonable process.” Neah Bay, 119 Wn.2d at 474. In determining this,
*436[t]his analysis requires the court to review the administrative record to determine the factors employed by the agency and the quality of its reasoning. The court must scrutinize the record to determine if the result was reached through a process of reason, not whether the result was itself reasonable in the judgment of the court.
Neah Bay, 119 Wn.2d at 474 (emphasis added). To a large extent this discussion is redundant with the discussion above of whether the Department relied upon the “best available evidence” as required under the WISHA. See RCW 49.17.050(4).
This case is quite unlike Neah Bay, where “[n]o rule-making file is on the record; indeed, the record does not contain any reference to agency files or any other sort of administrative record.” Neah Bay, 119 Wn.2d at 475. Here the administrative record was extensive. The CES expressly states that the EPA report in that record, among other reports, was relied upon in determining that ETS poses lung cancer and cardiovascular disease risks—and the Department’s officials characterized the risk of lung cancer posed by ETS as significant in their testimony and offered a very “plausible” explanation for why that risk was statistically unquantifiable. Neah Bay, 119 Wn.2d at 471.
The Companies note that the United States Supreme Court has written that “the courts may not accept appellate counsel’s post hoc rationalizations for agency action.” State Farm, 463 U.S. at 50. Yet there is more than enough information in the CES and the trial record that even under State Farm the Department’s action could be “upheld, if at all, on the basis articulated by the agency itself,” State Farm, 463 U.S. at 50, and any appellate rationalizations would be overkill anyway. This despite the fact that the Companies are correct in a debate with the Department, centering upon a page of a law review article cited in Neah Bay, over which of three models of rationality review described by Professor Funk that we came closest to. In Neah Bay the third model, based upon Pacific States Box & Basket Co. v. White, 296 U.S. 176, 185-86, 56 S. Ct. 159, 80 *437L. Ed. 138, 101 A.L.R. 853 (1935), was clearly referred to as “discredited.” Neah Bay, 119 Wn.2d at 472. The first model, which the Companies favor, mirrors the State Farm language in that in support of a regulation it “does not allow the explanatory justification to be supplied merely by an attorney’s affidavits or briefs in court.” Funk, 43 Admin. L. Rev. at 157-58 (emphasis added). Instead, it “presumes an agency explanation or justification for the rule ... although the model does not necessarily require the explanation to be contemporaneous with the rule.” Funk, 43 Admin. L. Rev. at 157 (emphasis added) (footnote omitted). Thus, even though we follow that model, it is a Pyrrhic victory for the Companies. It further proves that their position is incorrect on the first issue above, inasmuch as the explanatory trial testimony of the Department’s officials was not barred.
We cannot, however, agree with the Department and follow Funk’s second model:
A second model accepts the idea of the record of an agency rulemaking but rejects the requirement for an agency explanation of the rule. Under this model, the record remains the mass of information considered by the agency in the course of the rulemaking . . . but the agency is not obliged to explain how it reached its conclusion from that information. . . . [T]he court does not review the agency’s explanation of how and why it adopted the rule from this information. Rather, the court reviews the information to determine whether a rational decision-maker could have reached the conclusion the agency did on the basis of the information before it.
Funk, 43 Admin. L. Rev. at 158. Although this language mirrors some of that found in Neah Bay, its permissiveness is at odds with the undeniable requirement under the APA “for an agency explanation of the rule”—namely, the CES. Furthermore, other considerations strongly militate against embracing this model, such as the risk that the court might substitute its judgment for that of the agency—which is expressly barred by Neah Bay and the APA. This court “shall not itself undertake to exercise the discretion that the legislature has placed in the agency.” RCW 34.05.574(1).
*438To a large extent, however, this debate is splitting hairs and irrelevant to the resolution of this case. As Professor Funk has noted, under either the first or second models “[t]he agency invariably will articulate in the litigation an explanation for the rule and how it is derived from the record, and the court will undoubtedly subject that explanation to. scrutiny,” making the approach to judicial review under the two models “similar, if not identical.” Funk, 43 Admin. L. Rev. at 159.
The Companies correctly observe that the Department elected to rely upon the EPA report and other studies without conducting its own study. This decision to not duplicate the efforts of other studies and to rely upon those already reported appears to have been “plausible,” and “reached through a process of reason.” Neah Bay, 119 Wn.2d at 471, 474. Significantly, there is no evidence that the Department acted arbitrarily or capriciously in so deciding. The Companies were allowed to make their case, and 15 boxes of administrative record reveal that they did so vigorously. The Companies try to add to known rationality review requirements that the decision to promulgate the ETS regulation must be based upon both a “rational and expert analysis of the administrative record,” Appellants’ Br. at 2 (emphasis added), but they cite no real authority for this argument other than to make the assertion that the Department chose to “rely blindly on reports from other government entities in the face of specific and detailed contrary scientific evidence in the administrative record.” Appellants’ Br. at 60 (emphasis added). They cite American Fed’n of Labor & Congress of Indus. Orgs. v. Occupational Safety & Health Admin., 965 F.2d 962, 984 (11th Cir. 1992) [hereinafter AFL-CIO], as forbidding such reliance. Again, this is an attempt to import a federal opinion into a state case, but even there the court stated that “we do not believe that OSHA is required to independently research all aspects of its rules. . . . OSHA is entitled to rely on . . . consultants, as well as studies in the scientific literature”—although, of course, it must make those findings specifically required of it by statute. AFL-CIO, 965 *439F.2d at 984. Moreover, the testimony of the Department’s officials makes it clear that they did not rely “blindly” on studies such as the EPA report, but chose to do so only after applying their expertise13 in weighing the available evidence.
Here the CES did contain “the agency’s reasons for adopting the rule,” RCW 34.05.355 (1992), and even though it was surely a “concise explanatory statement” it appears to have met statutory muster in its own right—with the permissible trial testimony of the Department officials only reinforcing it. “ ‘[T]he agency’s path may reasonably he discerned.’ ” Neah Bay, 119 Wn.2d at 471 (citation omitted). It is again important to emphasize that the ETS regulation is not a complete ban on smoking in private workplaces. The regulation limits only smoking indoors, and allows employers to provide smoking lounges. Furthermore, it does not restrict, in any way, smoking that occurs outdoors or in outdoor workplaces. With that understood, we conclude that it is clear that the ETS regulation could quite “conceivably have been the product of a rational decision-maker.” RCW 34.05.570(2)(c) (1992). Admittedly, our task would be easier were we able to champion one side or the other in this case. However, it is not for us to pass upon “whether the result was itself reasonable,” Neah Bay, 119 Wn.2d at 474, although the dissent would have us do so. Moreover, we are not free to make forays outside of the administrative record in order to cite authorities to support our decision.14 Nor, in interpreting Washington law, *440may we simply selectively defer to those federal opinions that support our views.
CONCLUSION
We are aware that issues surrounding the smoking of cigarettes have consumed much of the public’s interest in recent years. Efforts by the government to inhibit the public smoking of cigarettes have been, to say the least, controversial. Nevertheless, the Department of Labor and Industries has been vested with significant authority to protect the health and safety of Washington’s workers on the jobsite. We cannot say that the Department has abused that authority or acted irrationally here in regulating smoking in the workplace in an effort to protect the health of workers, both smokers and nonsmokers. We conclude, therefore, that both the APA and the WISHA were complied with in the promulgation of the ETS regulation and affirm the Thurston County Superior Court.
Guy, C.J., and Durham, Smith, Johnson, Madsen, and Talmadge, JJ., concur.
Known also as “involuntary smoking,” “passive smoking,” or colloquially as “second-hand smoking.”
These proposals addressed issues such as requiring planning prior to the remodeling of occupied offices to minimize degradation of indoor air quality, *416requiring documentation of maintenance and operation of heating, ventilation and air conditioning systems, and requiring the documentation of health symptoms and illnesses related to indoor air quality.
The Department’s rule-making file shall be referred to by the abbreviation AR, for “Administrative Record.” In any citation to the AR, the number preceding the colon is the volume number, the number following it is the page number.
The Companies do not renew here their earlier claims at summary judgment that the Department lacked the statutory authority to regulate smoking in private workplaces, that the Department violated the Regulatory Fairness Act, RCW 19.85, by failing to ameliorate the regulation’s impact upon small businesses, and that the Department failed in its duty under the APA, RCW 34.05.355(l)(b), repealed by Laws of 1995, ch. 403, § 305, to describe differences between the initial proposal and the regulation as adopted.
“The rulemaking file submitted to this court is the largest rulemaking file ever assembled by the Department.” Resp’ts’ Br. at 4.
The Companies may even be misreading federal law. “The court may require the administrative officials who participated in the decision to give testimony explaining their action. . . . [H]ere there are no . . . formal findings and it may be that the only way there can be effective judicial review is by examining the decisionmakers themselves.” Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 420, 91 S. Ct. 814, 28 L. Ed. 2d 136 (1971) (citations omitted), abrogated on other grounds by Califano v. Sanders, 430 U.S. 99, 105, 97 S. Ct. 980, 51 L. Ed. 2d 192 (1977)). The Companies attempt to limit Overton Park to its facts, but, perhaps tellingly, they cite no Supreme Court opinion which does so.
The Companies attempt to augment the test by stating that it also requires “the least restrictive means for reducing any risk.” Appellants’ Br. at 17 (emphasis added). This suggests the necessity of a cost-benefits analysis. Actually, the Court wrote in Benzene that “[b]ecause the Secretary did not make the required threshold finding ... we have no occasion to determine whether costs must be weighed against benefits in an appropriate case.” Benzene, 448 U.S. at 640. It would later hold that a “cost-benefit analysis by OSHA is not required.” American Textile Mfrs. Inst., Inc. v. Donovan, 452 U.S. 490, 509, 101 S. Ct. 2478, 69 L. Ed. 2d 185 (1981).
It is ironic to note here that benzene is just one of “more than 40 known or suspected human carcinogens” in tobacco smoke. AR 49: 30,280.
Instead the Companies offer cases such as Texas Independent Ginners Association v. Marshall, 630 F.2d 398 (5th Cir. 1980), where the Fifth Circuit vacated regulations that the OSHA had adopted governing cotton dust exposure at cotton gins. However, in Marshall the only cotton ginning studies that the OSHA had relied upon had been conducted at “primitive foreign gins” in Africa, Marshall, 630 F.2d at 408, and it had otherwise relied upon studies conducted at other types of cotton industries with conditions vastly different in nature than those of the domestic ginning industry. Marshall, 630 F.2d at 409. We do not have that apples and oranges dichotomy here. ETS is ETS. A better federal case for comparison’s sake would be Forging Industry Association v. Secretary of Labor, 773 F.2d 1436 (4th Cir. 1985), wherein the court upheld an OSHA occupational noise regulation, noting, without even a hint of disapproval, that OSHA had based its finding of a significant risk posed to hearing by noise upon data from studies that had all been conducted by other agencies and individuals outside of OSHA. See Forging Indus. Ass’n, 773 F.2d at 1445.
Other reports submitted by Philip Morris were even more damaging to the Companies’ position. One, a study that was also in the Department’s portion of the rule-making file, estimated that “[o]f 53,000 annual deaths in the United States attributed to passive smoking, 37,000 are attributed to heart disease compared with 3,700 for lung cancer.” AR 10: 13,004 (footnote omitted); AR 57: 34,264 (footnote omitted); Stanton A. Glantz & William W. Parmley, Passive Smoking and Heart Disease: Epidemiology, Physiology, and Biochemistry, 83 Circulation 1, 4 (1991) (footnote omitted). Another study estimated “35,000 to 40,000 annual excess heart disease deaths among never-smokers and long-term former smokers due to passive smoking” in addition to an estimated 3,000 lung cancer deaths. AR 10: 13,018; Kyle Steenland, Passive Smoking and the Risk of Heart Disease, 267 J. Am. Med. Ass’n 94, 99 (1992). By comparison, the EPÁ report, which “only” estimates 3,000 ETS-related annual cancer deaths, looks extremely conservative. Perhaps proving the old adage “less is more” the Companies may have overlooked the true import of these studies amidst the avalanche of documents they filed. In any event, they provided ample “smoking guns” in favor of the ETS regulation.
“In its ordinary meaning an activity is ‘feasible’ if it is capable of achievement, not if its benefits outweigh its costs.” Benzene, 448 U.S. at 719 (Marshall, J., dissenting) (citing Webster’s Third New International Dictionary 831 (1976)).
In such a case, compliance with the regulation would be achieved at no cost to employers, although the Companies, quite unconvincingly, assert that “decreased employee moral [sic]” is a “substantial” cost to industry resulting from the regulation. Appellants’ Br. at 51. One struggles to imagine how a working population composed of a vast majority of nonsmokers would somehow be demoralized by the absence from their workplaces of a substance that can kill *434them. Moreover, employer costs may actually be averted by the ETS regulation. McCarthy v. Department of Soc. & Health Servs., 110 Wn.2d 812, 814, 759 P.2d 351 (1988), involved a worker who, “[a]s a result of her constant exposure to tobacco smoke in the workplace,” developed chronic obstructive pulmonary disease that became “totally disabling” and forced her to quit her job. We held that employers can be directly sued for illness arising out of workplace exposure to tobacco smoke when such illness is not an occupational disease that falls within the basic coverage of the Washington Industrial Insurance Act, Title 51 ROW See McCarthy, 110 Wn.2d at 825.
Two board certified industrial hygienists analyzed the studies that the Department relied upon and advised then-Director Brown.
The dissent cites two law review articles, including one that was entirely outside the record of this case, to support the assertion that “[a]ntismoking regulations have a disproportionate effect upon the poor and African-Americans.” Dissent at 456 n.32 (citing Rivka Widerman, Tobacco is a Dirty Weed. Have We Ever Liked It? A Look at Nineteenth Century Anti-Cigarette Legislation, 38 Loy. L. Rev. 387, 421-22 (1992); John C. Toil, An Assessment of the Current Legal Climate Concerning Smoking in the Workplace, 13 St. Louis U. Pub. L. Rev. 591, 625 n.186 (1993)). Neither of these law review articles cite to any authority to support this statistical claim, and one strains to imagine the worst case scenario of being forced, in the absence of a smoking lounge, to smoke outside as an unendurable *440hardship. Could not the converse he arguably true, and in the absence of an ETS regulation the poor.—being the least mobile in the job market—would he unable to quit jobs where they would be subjected to cancer-causing tobacco smoke? Fox, heavily relied upon by the dissent, has “testified at the request of The Tobacco Institute at state legislative hearings on workplace smoking legislation.” Fox, supra, at 591 n.*. Would the dissent suggest that the Department rely upon works of advocacy instead of science? The dissent would require the Department to presciently comply with statutory language not yet adopted at the time of the ETS regulation’s promulgation, by compelling it to use the CES to rebut all of the concerns raised by the Companies—without being first asked by the Companies to do so. See Dissent at 443 n.18. In short, the dissent “has taken nonlaw and treated it as the controlling interpretive key to the law as enacted. ” Pacific N.W. Bell Tel. Co. v. Department of Revenue, 78 Wn.2d 961, 969, 481 P.2d 556 (1971) (Hale, J., dissenting). This approach raises interesting questions: “How will future legislatures and their codifiers preserve for us the nonlaw, the imaginary sections of statutes which could have been but were never enacted? How lay to rest the ghosts of laws never passed?” Pacific N.W. Bell, 78 Wn.2d at 969 (Hale, J., dissenting).