Document JNZy4QL5Qp5ZgD2wVXqV2ZbwK

2008-Aug-21 01 :03 PM 3M JC3111 O. JYY4t:t~Gy Staff vice Presidcnt 6517331773 ..... ----------- -------- -. .- safety Operations _ _ p-1 110 Box 33331 St Paul, MN 55133-3331 651 7Y8 5A13II 2/2 CERTIFIED MAIL 20?a August 14, 2008 Document Processing Center EPA Ilast ~ Room 6428 Attn : Section $(e) Office of Pollution Prevention and Toxics -U.S, EPA 1200 Pennsylvania AvenueNW Washington, DC 20460-0001 ):te~ TSCA 8(e) Substantial Risk Notice : Supplemental to Docket No . 8F~HQ-0598-373 ; Sultbna.i:c-based and Carboxylate-bawd rluorochemic:als '1'o whom it may concern: 3M 1,4 submitting this notice lo supplement its previous submissions oJ1 Sulfonlte and oKrboxylatebased tluorochemicals_ 3M recently received data from a 13 week dietary study on perthioroocl:an45ulfonate (Pl~OS) in ---rats . Thc study was designed to investigate the reversibility o:Chepatomega,lly and thyroid effects previously demonstrated iii rats exposed to PFOS . Rats were administered either 20 or 100 ppm ~ i'F'OS in the diet ad lfhitxm~ for 7 days . This was followed by an 84-day recovery period during all animals were fed untreated c.how . Ten animal-, were sacrificed l:rom each group on ~whic~ ReLidy (lays $, 36, 64, and 92 . At sa .ciifxoc, various sHmp108 were collected for various analyses. 1'FOS treatment had no elY'cet on the thyroid parameters evaluated. Previously documwii:od hepatic effects were observcd, arid reversibility of these effects was not Complete . Hepatic apoptosis had not completely revcrscd following the 84 day recovery period . In addition, microsomal cytochrorne P450 conloilt and representative monoxygenase activities were maintained through thc treatment-frcQ recover period . While the biological significance of dicsc observations reniains unclear, and 3:IVT does not believe that ally of thes~ data takcn alone or cumulatively meet the "substantial risk" reporting threshold, vve nevertheless x'ecogni.i,c the ongoing work by U.S . El'A to assess f[uorochemiaal oxposure pathways . Therefore, we are placing these msult.q in the 8(e) dockcl: as a supplement to provious submissiorts . if you have any questions or would like any additional inf.ormation, plea5u contact Deanna Luebker at (651) 737-1371 or d'lue~tnnr.com . . , Sincerely c~, a .lcia~t~ cxo/> Jean D, Swccney Staff Vice 1'r4sident, 3M Environmental, Health and Safe(.y Operations }?nclosurc i ~~I ~: ~ ~~i 1[1111 11''~~ ! ~i1i111 ~I~I I11'i F 'l 0 F () 0 11 Il _ . 6