Document 2JME5E5oy11QrZKVVwOQMgRN

Katherine E . Reed, P hJ). S taff Vice R esident 3M Environm ental technology and Safety Services 900 Bush Avenue Building 42-2E-26 PO Box 33331 St R ail, M N 55133-3331 651 778 4331 CERTIFIED MAIL October 30,2002 Document Processing Center (7407M) EPA E a st-R o o m 6428 Attn: Section 8(e) Office o f Pollution Prevention and Toxics US EPA 1200 Pennsylvania Ave., NW Washington, DC 20460-0001 TSCA 8(E) SUBSTANTIAL RISK NOTICE ON: Perfluorohexane sulfonate potassium salt Reference 8EHQ-1180-373, 374 Dear S ir 3M recently sponsored an "Oral (Gavage) Combined Repeated Dose Toxicity with the Reproductive/Developmental Toxicity Screening Test" Study o f perfluorohexane sulfonate potassium salt (PFHS), T-7706. The study was conducted at Argus Research Charles River Laboratories, Horsham, Pennsylvania. The preliminary draft results include certain findings that appear appropriate for TSCA section 8(e) submission. Parental male rats were dosed for at least 42 days. Parental females were dosed for approximately 60 days. No PFHS related effects were observed in the parental females. The adverse effects noted in parental male rats exposed to PFHS included: (a) an increased absolute liver weight; an increased liver-to-body-weight ratio; and a liver-to-brain-weight ratio for both the 3 and 10 m/kg/day doses; (b) decreased average values for cholesterol in the 0 .3 ,1 ,3 and 10 mg/kg/day doses; (c) decreased triglycerides in the 10 mg/kg/day dose; (d) minimal to moderate enlargement o f centrilobular hepatocytes in the 3 and 10 mg/kg/day doses; and (e) increased incidence o f thyroid follicular cells hypertrophy and hyperplasia in the thyroid glands o f males in the 3 and 10 mg/kg/day doses. There were no signs o f neurological, developmental or reproductive effects. A copy o f this study report w ill be sent to EPA when received. A previously reported Exploratory 28-day Oral Toxicity Study conducted with PFHS, among other compounds, demonstrated some o f these same adverse effects. See Letter from 3M to 8(e) Docket, August 21,2000 (requesting this and other studies to be moved from AR-226 to the 8EHQ -1180-373,374 docket). Office o f Pollution Prevention and Toxics Page No. 2 October 30,2002 Please contact Dr. John Butenhoffi 3M Corporate Toxicology and Regulatory Services, 651-733-1962, for further information. Katherine E. Reed StaffVice Prsidait, Environmental Technology and Safety Services