Document v1y8zGzBgddvKYRYVaQpOY1Jm

Larry K. Zobel, &ID. > P H Stuff Vice President and Medic31 Director 3hl Medical Department BACK TO MAIN 3M Center, Buildirig 120-2E-01, PO %ox 33210 St. Paul, MN 55133-3220 65 I 733 5 18 1 Office 651 733 5152 Fax 3M - -, May 24,2001 Document Processing Center (7407) Attn: Section 8(e) Coordinator Office of Toxic Substances USEPA 401 M Street, SW Washington, DC 20460 TSCA 8(e) SUBSTAWTIALRISK NOTICE: potassium perfluorooctanesulfonate (CASkV 2795-39-3) Dear 8(e) Coordinator: 3M has received a draft statistical report from Covance Laboratories in connection with a two-year dietary study of potassium perfluorooctanesulfonate (PFOS) in rats. The final report for this study is in preparation; however, the data from the statistical report are believed to represent information which meet the reporting threshold for section 8(e) of TSCA. In the study design, male and female rats were assigned to a control group or one of five dosed groups that received PFOS mixed into their feed. The dietary dose levels were 0.5, 2, 5, and 20 parts per million (ppm) plus an additional "recoveTy" group at 20 ppm for which dosing ended at one year and the rats were allowed to recover through the end of the study. The attached table summarizes the relevant findings. When the final report on this study becomes available, it will be submitted to the EPA. The findings of statistical significance presented in the attached table are not meant, in and of themselves, to imply biological significance. These data will be interpreted for biological significance in the final report. A considerable body of toxicity information on PFOS can be found in EPA docket AR-226. PFOS has been subjected to numerous assays for genotoxicity. The results of those assays show a lack of genotosicity. Please contact me for hrther information. Regards, III Lk&y d Z o b e l , MD MPH Staff Vice President & Medical Director c: Dr. Charles Auer Dr. Oscar Hernandez Attachment BACK TO MAIN k TABLE: RESULTS OF STATISTICAL ANALYSIS OF SELECTED NEOPLASTIC LESIONS FROM TWO-YEAR DIETARY STUDY OF PFOS IN RAI'S. Tumor Hepatocellular Adenoma I-IepatoceiluIar C a r c i n o i i a Historical Control (a) 4/394 (1 .O %) (0 Yo-4.3 %) 0/394 (0 Yo) Control 0/60 (0 %) trend*(b) 0/60 (0 Yo) 0.5 ppm 1/50 (2.0 Yo) 0/50 (0 Yo) 2 PPm 1/49 (2.0 Yo) 0/49 (0 Yo) 5 PP" 1/50 (2.0 Yo) 0/50 (0 Yo) 20 ppm 5/60 (8.3 Yo)* 1/60 (1.7 %) Hepatocellular Adenoma & Carcinoma NA (0 Yo - 4.3 %) 0/60 (0 %) trend** 1/50 (2.0 %) 1/49 (2.0 %) 1/50 (2.0 %) 6/60 (10.0 Yo)* MALES Tumor EIepatocellular Adenoma Pancreatic Islet Cell Carcinoma Thyroid Follicular-Cell Adenoma Thyroid Follicular-Cell Carcinoma Thyroid Follicular-Cell Adenoma & Carcinoma Historical Control 6/393 (1.5 %) (0 % - 3.3 %) 5/390 (1.3 %) (0 % - 4.8 %) 171391 (4.3 %) (0 % - 11.3 YO) 4391 (1.0%) (0 YO- 3.2 Yo) NA (0 YO- 14.5 Yo) * denotes statistical significance at p < 0.05 * * denotes statistical significance at p < 0.01 Control 0/60 (0 %) trend* Oh0 (0 %) trend* 3/60 (0 Yo) 3/60 (5.0 %) 6/60 (10.0 Yo) . 0.5 ppm 3/50 (6.0 %) 2/49 (4.1 %) p = 0.1793 5/49 (10.2 %) 1/49 (2.0 %) 6/49 (12.3 Yo) 2 PPm 3/50 (6.0 %) 1/50 (2.0 %) NA 4/50 (8.0 %) 1/50 (2.0 Yo) 5/50 (10.0 %) 5 PPm 1/50 (2.0 Yo) 4/50 (8.0 %) p = 0.2148 4/49 (8.2 %) 2/49 (4.1 Yo) 5/49 (10.2 %) 20 PPm 7/60 (1 1.7 Yo)* 5/50 (10.0 %) p = 0.0463* 4/59 (6.8 Yo) 1/59 (1.7 Yo) 5/59 (8.5 %) a) Data from six prior two-year studies with Sprague - Dawley rats in the same laboratory. b) The significance indications in the control column are one-tailed for trend. c) For high-dose recovery values, the significance is for one-tailed, pair-wise comparison to the high-dose group. d) For high-dose recovery values, the significance is for one-tailed, pair-wise comparison to the control and high-dose group. 20 ppm Rec 2/40 (5.0 Yo) - 0140 (0 %) 2/40 (5.0 %) _. 20 ppm Rec 0/40 (O%G)*'') 3/40 ( 7 . 5 7 i F 913 9 (23.1 %)*(dl 1/39 (2.6 %) 10139 (15.6Yo)*")