Ethyl Corp. v. EPA, 541 F.2d 1 (D.C. Cir. 1976) (en banc), cert. denied, 426 U.S. 941 (1976)
Ethyl Corp. v.
Does § 211(c)(1) of the Clean Air Act authorize EPA to restrict lead in gasoline based on a finding that emissions from the additive will endanger public health or welfare without conclusive proof of actual harm, and were EPA's regulations supported by substantial evidence and procedurally valid?
Under Clean Air Act § 211(c)(1), the Administrator may control or prohibit a fuel or fuel additive if, in his judgment, any emission product of such fuel or additive will endanger the public health or welfare. The statutory term "endanger" embodies a preventive, forward-looking standard that permits regulation on the basis of significant risk supported by credible evidence, even absent definitive causation or quantification of harm. Judicial review in this context proceeds under the substantial-evidence standard on the record as a whole (as prescribed by the Clean Air Act's review provisions for such rulemaking), with courts according deference to the agency's technical expertise and predictive judgments, so long as the agency considered relevant factors, responded to significant comments, and reasonably explained its choices.
Yes. EPA reasonably interpreted and applied § 211(c)(1) to regulate lead in gasoline on a preventive "endangerment" basis, and its finding that emissions from leaded gasoline pose a significant risk to public health—particularly to children—was supported by substantial evidence in the rulemaking record. The court rejected the procedural challenges and upheld the lead phase-down regulations.
Ethyl is a cornerstone of administrative and environmental law. It affirms that health-protective statutes authorize preventive regulation amid scientific uncertainty and that courts will defer to agency expertise when the agency has marshaled substantial evidence and offered a reasoned explanation. The case is frequently cited for its articulation of an environmental "precautionary" approach under statutory endangerment standards, influencing subsequent risk regulation cases across domains. For law students, Ethyl crystallizes several doctrinal points: (1) how statutory text ("will endanger") drives a preventive regulatory posture; (2) what substantial-evidence review entails in a hybrid rulemaking; (3) the permissible role of predictive judgments in agency policymaking; and (4) the limits of procedural challenges—such as ex parte contacts—when the rulemaking record and rationale are adequate for judicial review.