ELR Citation: ELR 21146
No(s). s. 86-4161, 87-4451 (5th Cir. Aug 19, 1987)

The court holds that the Environmental Protection Agency's (EPA's) newly promulgated regulation under §4(a)(1) of the Toxic Substances Control Act (TSCA) requiring manufacturers and processors to test mesityl oxide (MO) for its health effects must be stayed pending further agency fact-finding. EPA and plaintiff chemical companies, who challenge the regulation, dispute whether post-promulgation developments indicate an increase or decline in the use of MO. The nature of these developments is highly relevant to determining whether there is substantial evidence to show that MO may present an "unreasonable risk to human health," and that a testing program is therefore required under TSCA §4(a)(1). The court remands the case to EPA for updated fact-finding and a reconsideration of the testing regulation.

Counsel for Petitioners
Robert M. Sussman
Covington & Burling
1201 Pennsylvania Ave. NW, P.O. Box 7566, Washington DC 20044
(202) 662-5270

David D. Sigman
Exxon Chemical Americas
13501 Katy Freeway, P.O. Box 3272, Houston TX 77253-3272
(713) 870-6149

Counsel for Respondent
Beth S. Ginsberg
Land and Natural Resources Division
Department of Justice, Washington DC 20530
(202) 633-2689

David A. Hansell
Berle, Kass & Case
45 Rockefeller Plaza, New York NY 10111
(212) 765-1800

Before RUBIN, GARZA, and JOLLY, Circuit Judges.