ELR Citation: ELR 20837
No(s). 88-4710 (5th Cir. Apr 12, 1990)

The court generally upholds the Environmental Protection Agency's (EPA's) final rule, promulgated under §4(a)(1)(B) of the Toxic Substances Control Act, requiring manufacturers and processors of the chemical cumene (isopropyl benzene) to test the chemical's health and environmental effects. The court first rejects a chemical industry trade association's challenge that EPA's estimate of annual fugitive cumene emissions to the atmosphere is exaggerated, finding that EPA's estimate is supported by substantial evidence on the rulemaking record. Although the court next sustains the challenge to EPA's finding that cumene releases to the aquatic environment are expected, the court holds that this deficiency does not invalidate EPA's findings under §4(a)(1)(B) as to either the substantial quantities entering the environment or as to potential human exposure. It seems likely that EPA's findings would have been the same even absent the subsidiary finding as to release into the aquatic environment. Next, the court notes that EPA is not obliged to accept the trade association's definition of "substantial," as used in clauses (I) or (II) of §4(a)(1)(B)(i). However, since neither EPA's proposed rule nor the final rule sheds light on how EPA defines "substantial," the court remands the rule to EPA to articulate on the record the standards or criteria it used to define "substantial" in terms of the quantities of cumene entering the environment and the resulting potential human exposure. During the period of remand, the court refuses to stay EPA's final rule.

Counsel for Petitioners
Julia A. Hatcher, Robert M. Sussman
Latham & Watkins
1001 Pennsylvania Ave. NW, Ste. 1300, Washington DC 20005
(202) 637-2200

Counsel for Respondent
Kaye A. Allison
Land and Natural Resources Division
U.S. Department of Justice, Washington DC 20530
(202) 514-4198

Before KING, GARWOOD, and DAVIS, Circuit Judges.