Document GKRop6GvaONM9Z4LOV0wyJb0m

Katherine E. Reed, Ph.D. Staff Vice President 3M Environmental, Health and Safety Operations 900 Bush Avenue, Building 42-2E-26 PO Box 33331 St. Paul, MN 55133-3331 651 778 4331 Certified Mail February 24,2004 Document Processing Center EPA East - Room 6428 Attn: Section 8(e) Office o f Pollution Prevention and Toxics US EPA 1200 Pennsylvania Avenue NW Washington DC 20460-0001 RE: TSCA 8(E) SUPPLEMENTAL SUBMISSION: Docket No. 8EHQ-1180-373 Dear Sirs: 3M has received final results for an oral pharmacokinetic study in rats conducted with perfluorooctanesulfbnyl fluoride (POSF, CAS# 307-35-7) indicating that the test substance metabolizes to perfluorooctane sulfonate (PFOS, CAS# 2795-39-3). The study was conducted by 3M's Strategic Toxicology Laboratory. A single oral dose o f 5 mg/kg POSF was administered to 15 male rats. Necropsies were performed on days 1 ,4 , and 29 post dose. The study results indicate that POSF was metabolized to PFOS. Maximum PFOS in the liver occurred on day 4 post dose at approximately 11 ppm, or 10% o f the dose. On days 1 and 29 post dose, the PFOS concentration in the liver was 7 and 4 ppm, respectively. POSF was used as an intermediate gas in an isolated industrial process to produce PFOS and related products. 3M no longer manufactures POSF. Enclosed please find the final study titled "Pharmacokinetic Study o f Perfluorooctanesulfonyl Fluoride (POSF) Following a Single Oral Gavage Dose in R ats." Please contact Andrew Seacat (651-575-3161) if you have any questions or if we can provide additional information. Katherine E. Reed Staff Vice President Environmental, Health and Safety Operations Enclosure