Document bamKpyMnp78XNjwXzadn541y0

3M Medical Department Corporate Toxicology 3M Center, Building 220-2E-02 St. Paul, MN 55144-1000 651 733 1773 Fax |089(f S6m-OI02>-003>73> AR- or 2003 FEB 19 H 9* O* 3M Certified Mail January 27, 2003 Document Processing Center EPA East - Room 6428 Attn: Section 8(e) Office of Pollution Prevention and Toxics US EPA 1200 Pennsylvania Avenue NW Washington DC 20460-0001 & EPA-OTS 000811853Q ODllS3(3 RE: TSCA 8(E) SUPPLEMENTAL SUBMISSION: Docket No. 8EHQ-998-374 Perfluorooctane Sulfonate (PFOS) CAS# 2795-39-3 Dear Docket Coordinators: 3M has previously informed the EPA (September 14, 1998) of the results of a multi generation reproductive/developmental study in rats conducted with potassium perfluorooctane sulfonate (PFOS) in which perinatal mortality occurred in the Fi generation pups at the two highest dose levels (1.6 and 3.2 mg/kg/day). 3M subsequently informed the EPA (March 28, 2001) of the results of a follow-up study that more precisely defined the No-Observed-Effects Level (0.4 mg/kg/day) and the mechanism for the observed toxicity. In today's submission, 3M has new results to report from a study conducted to better define the dose-response for the perinatal effects previously observed. 3M has received a final report (see enclosure) indicating an effect on mean pup body weight per litter at the lowest maternal treatment level (0.4 mg/kg/day) that was statistically significant (p < 0.05) on post-natal days 1-5 when compared to control litters. The effect on mean pup body weight per litter also displayed a dose-response over the range of doses tested (0.4, 0.8, 1.0, 1.2, 1.6, and 2.0 mg/kg/day). The lower 95% confidence interval of the benchmark dose representing a 10% decrease in mean pup weight per litter on post-natal day 1 was 0.88 mg/kg/day maternal dose. Please contact John Butenhoff (651-733-9162) if you have any questions or if we can provide additional information. Sinrprp.lv Larry R. Zobel, MD MPH Staff Vice President and Medical Director Enclosure (M M & Wik