dissenting from Part I:
The Clean Air Act has been on the books for decades, has been amended by Congress numerous times, and has been the subject of regular congressional oversight hearings. The Act has been parsed by this circuit no fewer than ten times in published opinions delineating EPA authority in the NAAQS setting process. Yet this court now threatens to strike down section 109 of the Act as an unconstitutional delegation of congressional authority unless EPA can articulate an intelligible principle cabining its discretion. In doing so, the court ignores the last hálf-century of Supreme Court nondelegation jurisprudence, apparently viewing these permissive precedents as mere exceptions to the rule laid down sixty-four years ago in A.L.A. Schechter Poultry Corp. v. United States, 295 U.S. 495, 55 S.Ct. 837, 79 L.Ed. 1570 (1935). Because section 109’s delegation of authority is narrower and more principled thah delegations the Supreme Court and this court have upheld since Schechter Poultry, and because the record in this case demonstrates that EPA’s discretion was in fact cabined by section 109,1 respectfully dissent.
Section 109 requires EPA to publish air quality standards “the attainment and maintenance of which in the judgment of the Administrator, based on such criteria and allowing an adequate margin of safety, are requisite to protect the public health.” 42 U.S.C. § 7409(b)(1) (1994). Compare section 109 to the language of section 303 of the Communications Act of 1934, which gave the FCC authority to regulate broadcast licensing in the “public interest,” and which the Supreme Court sustained in National Broadcasting Co. v. United States, 319 U.S. 190, 225-26, 63 S.Ct. 997, 87 L.Ed. 1344 (1943). The FCC’s general authority to issue regulations “as public convenience, interest, or necessity requires” was sustained in United States v. Southwestern Cable Co., 392 U.S. 157, 178, 88 S.Ct. 1994, 20 L.Ed.2d 1001 (1968). The Supreme Court has sustained equally broad delegations to other agencies, including the Price Administrator’s authority to fix “fair and equitable” commodities prices, Yakus v. United States, 321 U.S. 414, 426-27, 64 S.Ct. 660, 88 L.Ed. 834 (1944), the Federal Power Commission’s authority to determine “just and reasonable” rates, FPC v. Hope Natural Gas Co., 320 U.S. 591, 600, 64 S.Ct. 281, 88 L.Ed. 333 (1944), the War Department’s authority to recover “excessive profits” earned on *1058military contracts, Lichter v. United States, 334 U.S. 742, 778-786, 68 S.Ct. 1294, 92 L.Ed. 1694 (1948), and the Attorney General’s authority to regulate new drugs that pose an “imminent hazard to public safety,” Touby v. United States, 500 U.S. 160, 165, 111 S.Ct. 1752, 114 L.Ed.2d 219 (1991). See also Milk Indus. Found. v. Glickman, 132 F.3d-1467, 1475 (D.C.Cir.1998).(upholding delegation to Secretary of Agriculture to approve interstate compacts upon a finding of “compelling public interest”).
Given this extensive Supreme Court precedent sustaining general congressional delegations, no wonder the First Circuit rejected a similar nondelegation challenge to the Clean Air Act’s “requisite to protect the public health” language:
The power granted to EPA is not “unconfined and vagrant”. [Schechter Poultry, 295 U.S. at 551, 55 S.Ct. 837 (Cardozo, J., concurring).] The Agency has been given a well defined task by Congress — to reduce pollution to levels “requisite to protect the public health”, in the case of primary standards. The Clean Air Act outlines the approach to be followed by the Agency and describes in detail many of its powers.... Yet there are many benchmarks to guide the Agency and the courts in determining whether or not EPA is exceeding its powers, not the least of which is that the rationality of the means can be tested against goals capable of fairly precise definition in the language of science.
Administrative agencies are created by Congress because it is impossible for the Legislature to acquire sufficient information to manage each detail in the long process of extirpating the abuses identified by the legislation; the Agency must have flexibility to implement the congressional mandate. Therefore, although the delegation to EPA was a broad one, ... we have little difficulty concluding that the delegation was not excessive.
South Terminal Corp. v. EPA, 504 F.2d 646, 677 (1st Cir.1974).
I do not agree with my colleagues that International Union, UAW v. OSHA, 938 F.2d 1310 (D.C.Cir.1991) (“Lockout/Tagout /”), requires a different result. That case remanded to OSHA for a more precise definition of section 3(8) of the Occupational Safety and Health Act, which granted the Agency authority to enact workplace safety standards “reasonably necessary or appropriate to provide safe or healthful employment or places of employment.” Id. at 1316. The Clean Air Act does not delegate to EPA authority to do whatever is “reasonably necessary or appropriate” to protect public health. Instead, the statute directs the Agency to fashion standards that are “requisite” to protect the public health. In other words, EPA must set pollution standards at levels necessary to protect the public health, whether “reasonable” or not, whether “appropriate” or not.
Moreover, in setting standards “requisite to protect the public health,” EPA discretion is not unlimited. The Clean Air Act directs EPA to base standards on “air quality criteria” that “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health or welfare which may be expected from the presence of such pollutant in the ambient air, in varying quantities.” 42 U.S.C. § 7408(a)(2); see id. § 7409(b)(1); see also id. § 7408(a)(2) (requiring air quality criteria, “to the extent practicable,” to “include information on — -(A) those variable factors (including atmospheric conditions) which of themselves or in combination with other factors may alter the effects on public health or welfare of such air pollutant; (B) the types of air pollutants which, when present in the atmosphere, may interact with such pollutant to produce an adverse effect on public health or welfare; and (C) any known or anticipated adverse effects on welfare”). Indeed, the principles constraining EPA discretion are at least as *1059specific as those this court sustained in International Union, UAW v. OSHA, 37 F.3d 665, 669 (D.C.Cir.1994) (“Lockout/Tagout II”), i.e., that OSHA must identify a “ ‘significant’ safety risk, to enact a safety standard that provides ‘a high degree of worker protection’.” By directing EPA to set NAAQS at levels “requisite”— not reasonably requisite — to protect the public health with “an adequate margin of safety,” the Clean Air Act tells EPA exactly the same thing, i.e., ensure a high degree of protection.
Although this court’s opinion might lead one to think that section 109’s language permitted EPA to exercise unfettered discretion in choosing NAAQS, the record shows that EPA actually adhered to a disciplined decisionmaking process constrained by the statute’s directive to set standards “requisite to protect the public health” based on criteria reflecting the “latest scientific knowledge.” To identify which health effects were “significant enough” to warrant protection, EPA followed guidelines published by the American Thoracic Society. See National Ambient Air Quality Standards for Ozone: Proposed Decision, 61 Fed.Reg. 65,716, 65,722/1 (1996). It then set the ozone and fine particle standards within ranges recommended by CASAC, the independent scientific advisory committee created pursuant to section 109 of the Act. See 42 U.S.C. § 7409(d)(2).
CASAC must consist of at least one member of the National Academy of Sciences, one physician, and one person representing state air pollution control agencies. See id. § 7409(d)(2)(A). In this case, CASAC also included medical doctors, epidemiologists, toxicologists and environmental scientists from leading research universities and institutions throughout the country. EPA must explain any departures from CASAC’s recommendations. See id. § 7607(d)(3). Bringing scientific methods to their evaluation of the Agency’s Criteria Document and Staff Paper, CASAC provides an objective justification for the pollution standards the Agency selects. Cf. Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 593, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993) (“ ‘Scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified; indeed, this methodology today is what distinguishes science from other fields of human inquiry.’ ”) (citation omitted). Other federal agencies with rulemaking responsibilities in technical fields also rely heavily on the recommendations, policy advice, and critical review that scientific advisory committees provide. See, e.g., 21 U.S.C. § 355(n) (describing scientific advisory panels for the Food and Drug Administration); 49 U.S.C. § 44912(c) (creating a scientific advisory panel for the Federal Aviation Administration).
Beginning with CASAC’s ozone recommendations — not one member recommended going below .08 ppm — EPA gave two perfectly rational explanations for the level it selected. First, it set the annual level based on the different types of health effects observed above and below .08 ppm. Particularly below .08, the Agency determined, “[t]he most certain [ozone-Jrelated effects, while judged to be adverse, are transient and reversible.” National Ambient Air Quality Standards for Ozone, 62 Fed.Reg. 38,856, 38,868/2 (1997) (emphasis added). Characterizing this explanation as saying nothing more than that “lower exposure levels are associated with lower risk to public health,” Maj. Op. at 1035, my colleagues find the Agency’s reasoning unintelligible. But EPA did not find simply that public health risks decrease at lower levels. Instead, it found that public health effects differ below .08 ppm, i.e., that they are “transient and reversible.”
Second, EPA explained that the level should not be set below naturally occurring background ozone concentrations. The Agency selected .08 ppm because it found that “a 0.07 ppm level would be closer to peak background levels that infrequently occur in some areas due to *1060nonanthropogenic sources of [ozone] precursors, and thus more likely to be inappropriately targeted in some areas on such sources.” 62 Fed.Reg. at 38,868/3. Of course, any level of ozone pollution above background concentrations is closer to background levels than one just above it. See Maj. Op. at 1036. But as I read EPA’s explanation, the Agency found that peak background levels sometimes occur at .07 ppm, not at .08 ppm. Indeed, the data EPA provided in its “Responses to Significant Comments” show a range of background concentrations from a low of .042 ppm in Olympic National Park in Washington to a high of .075 ppm in Quachita National Forest in Arizona. No region registered background levels above .075 ppm. See U.S. EnviRONMENTAL PROTECTION AGENCY, RESPONSES to Significant Comments on the 1996 Proposed Rule on the National Ambient Air Quality Standards for Ozone 94-96 (July 1997). In other words, by setting the annual standard at .08 rather than .07 ppm, EPA ensured that if a region surpasses the ozone standard, it will do so because of controllable human activity, not because of uncontrollable natural levels of ozone.
EPA offered an equally reasonable explanation for the fine particle pollution standard. Again limiting itself to the range approved by CASAC, EPA set the annual standard for PM2.5 pollution at the lowest level where it had confidence that the epidemiological evidence (filtered through peer-reviewed, published studies) displayed a statistically significant relationship between air pollution and adverse public health effects.
Recognizing that its decision must “accurately reflect the latest scientific knowledge useful in indicating the kind and extent of all identifiable effects on public health,” 42 U.S.C. § 7408(a)(2), EPA focused on three studies in the record that displayed a statistically significant relationship between fine particle pollution and adverse health effects: Joel Schwartz et al., Is Daily Mortality Associated Specifically with Fine Particles?, 46 J. Air & Waste Mgmt. Ass’n 927 (1996); Joel Schwartz et al, Acute Effects of Summer Air Pollution on Respiratory Symptom Reporting in Children, 150 Am. J. Respiratory & Critical Care Med. 1234 (1994); and Douglas W. Dockery et al., An Association between Air Pollution and Mortality in Six U.S. Cities, 329 New Eng. J. Med. 1753 (1993). The Agency explained that “there is generally greatest statistical confidence in observed associations [between fine particle pollution and adverse health effects] for levels at and above the mean concentration [of pollution observed in the studies that showed a statistically significant relationship].” National Ambient Air Quality Standards for Particulate Matter, 62 Fed.Reg. 38,652, 38,676/1 n.42 (1997) (emphasis added). Allowing “an adequate margin of safety,” EPA then set the annual fine particle standard just below the lowest mean pollution levels observed in those studies, at 15 |ig/m3. See id. at 38,676/1 (“An examination of the long-term means from the combined six city analyses of daily mortality [Schwartz et al. (1996) ] and morbidity [Schwartz et al. (1994) ], together with those from studies in individual cities for which statistically significant PM-effects associations are reported ... finds mean concentrations ranging from about 16 to about 21 g,g/m3 ....”); id. at 38,676/2 (“[The EPA] Staff Paper assessment of the concentration-response results [from Dockery et al. (1993) ], concluded that the evidence for increased risk was more apparent at annual concentrations at or above 15 |ig/m3 ....”).
In a passage directly answering this court’s concerns, see Maj. Op. at 1036-1037, the Staff Paper explained why the long-term mean served as a reasonable level for setting the fine particle NAAQS:
The mean (or median) concentration may serve as a reasonable cutpoint of increased PM health risk since at this point there is generally the greatest con*1061fidence (i.e., the smallest confidence intervals) in the association and the reported [relative risk] estimates. The mean concentration considered by staff as most informative to test implications of potential alternative concentration-response functions is the minimum mean concentration associated with a study or studies reporting statistically significant increases in risk across a number of study locations....
Office of Air Quality PlaNning and StandaRds, U.S. Environmental Protection Agenoy, Review of National Ambient Air Quality StandaRds for Partioulate Matter: PoliCY Assessment of Scientifio and TECHNICAL Information, at E-4 (1996) (emphasis added).
EPA thus did not, as my colleagues charge, arbitrarily pick points on the ozone and particulate pollution continua indistinguishable from any other. Instead, acting pursuant to section 109’s direction that it establish standards that, based on the “latest scientific knowledge,” are “requisite” to protect the public health with “an adequate margin of safety,” and operating within ranges approved by CASAC, the Agency set the ozone level just above peak background concentrations where the most certain health effects are not transient and reversible, and the fine particle level at the lowest long-term mean concentration observed in studies that showed a statistically significant relationship between fine particle pollution and adverse health effects. Whether EPA arbitrarily selected the studies it relied upon or drew mistaken conclusions frdm those studies (as petitioners argue), or whether EPA failed to live up to the principles it established for itself (as my colleagues believe, see Maj. Op. at 1035-1037), has nothing to do with our inquiry under the nondelegation doctrine. Those issues relate to whether the NAAQS are arbitrary and capricious. See NRDC v. EPA, 902 F.2d 962, 969, 971 (D.C.Cir.1990). The Constitution requires that Congress articulate intelligible principles; Congress has done so here.
A final point. Unlike OSHA, which Lockout/Tagout I recognized has authority to reach into every workplace to dictate what is safe, to impose extensive civil and criminal penalties, and “to decide which firms will live and which will die,” Lockout/Tagout I, 938 F.2d at 1318, EPA regulates primarily by setting standards for states to develop their own plans. See 42 U.S.C. § 7401(a)(3) (Congress finds “that air pollution prevention ... and air pollution control at its source is the primary responsibility of States and local governments.”). Indeed, because states have three years to submit implementation plans, which are themselves subject to notice, comment, public hearing, and frequent renegotiation, we will not know for years precisely how the ozone and particle NAAQS will actually affect individual businesses. Only if a state fails to produce an acceptable plan can EPA terminate federal highway funds or impose its own implementation plan. Because the Clean Air Act gives politically accountable state governments primary responsibility for determining how to distribute the burdens of pollution reduction and therefore how the NAAQS will affect specific industries and individual businesses, courts have less reason to second-guess the specificity of the congressional delegation. Moreover, if the states disagree with the standards EPA has set, they have 535 representatives in Congress to turn to for help. In fact, legislation to overturn the very NAAQS at issue in this case was introduced in the last Congress. See H.R.1984, 105th Cong. (1997) (“A bill to provide for a four-year moratorium on the establishment of new standards for ozone and fine particulate matter under the Clean Air Act, pending further implementation of the Clean Air Act Amendments of 1990, additional review and air quality monitoring under that Act.”);S. 1084, 105th Cong. (1997) (“A bill to establish a research and monitoring program for the national ambient air quality standards for ozone and particulate matter and to reinstate the original standards un*1062der the Clean Air Act, and for other purposes.”)-