Opinion ID: 365968
Heading Depth: 3
Heading Rank: 1

Heading: EPA's policy judgments concerning extrapolation.

Text: 76 Industry petitioners contend that EPA lacked an adequate basis for the regulations under review because of the incomplete scientific knowledge about less chlorinated PCBs. In effect, they assert that EPA must demonstrate the toxicity of each chemical it seeks to regulate through studies demonstrating a clear line of causation between a particular chemical and harm to public health or the environment. We do not agree. 77 The principal basis for rejecting petitioners' views is the wording of the statute. As we stated, the ample margin of safety provision directs EPA to guard against incompletely known dangers. EPA, in its expert policy judgment, relied on its knowledge about a known substance to assess the danger of one about which less is known. Petitioners suggest no alternative approach for the agency short of waiting for conclusive proof about the danger posed by a less understood substance. However, by requiring EPA to set standards providing an ample margin of safety, Congress authorized and, indeed, required EPA to protect against dangers before their extent is conclusively ascertained. The statute thus does not deny EPA the authority that petitioners would have us withhold. Indeed, the legislative history indicates that Congress intended EPA to take into account the availability of data on similar substances or compounds. 74 Moreover, the Clean Water Act of 1977 supports the notion that extrapolation from data about related substances is a valid approach. In 1977, Congress did not list individual substances, but rather listed families of substances, 75 recognizing that similarities among substances render them susceptible to regulation by group. 76 78 Proper deference in judicial review to the scientific expertise of the Administrator also militates against precluding EPA from regulating less chlorinated PCBs on the basis of what is known about related substances. Industrial Union Department, AFL-CIO v. Hodgson, 162 U.S.App.D.C. at 338-39, 499 F.2d at 474-75. 77 The risks posed by toxic substances, and the extent to which one substance has effects similar to those of related substances, are matters on the frontiers of scientific knowledge. EPA, not the court, has the technical expertise to decide what inferences may be drawn from the characteristics of related substances and to formulate policy with respect to what risks are acceptable. 78 79 Moreover, we are currently in a period of rapid change in assessing and regulating toxic substances. TSCA has established new regulatory mechanisms that may well lead to wholesale estimation of the risks of toxic substances. 79 A holding from this court that only one technique of risk assessment (such as extensive studies on comparative mammalian toxicity, Brief of Industry Petitioners at 53) is acceptable to the detriment of others would unnecessarily inhibit EPA from evaluating new approaches and formulating appropriate policy. 80 Finally, in reviewing EPA's policy of regulating less chlorinated PCBs in part on the basis of what is known about more chlorinated PCBs, we must recognize considerations of administrative feasibility. 80 The number of toxic substances subject to regulation seems very large. 81 Regulation of so many substances could well be extremely difficult if EPA were precluded from drawing inferences from available data on well-known, related substances. Moreover, requiring proof of causation for each chemical would force EPA to expend resources in areas that are well-enough known so that inference is acceptable, when those resources could be otherwise employed in areas where knowledge is inadequate. In ruling on the type of proof and procedure required for making individual determinations, the Supreme Court has construed statutes protecting the environment and public health in light of considerations of administrative feasibility. See E. I. du Pont de Nemours & Co. v. Train, 430 U.S. at 132, 97 S.Ct. 965 (type of proof); 82 Weinberger v. Hynson, Westcott & Dunning, Inc., 412 U.S. 609, 62-22, 93 S.Ct. 2469, 37 L.Ed.2d 207 (1973) (procedure). 83 See also United States v. Storer Broadcasting Co., 351 U.S. 192, 202-05, 76 S.Ct. 763, 100 L.Ed. 1081 (1956). 81