Document QpRkJ12Dm5QvZrLEOBgEZM57

3M General Offices /=V/-So/- )3,7g, 63S1Mt.2PC7a3eun3l,teM1r1N1055144-1000 FYI-00-001378 0T Ad 2 1 6 - IO cZO 3M April 25, 2001 FYI-00-001378 MOfrf.icCehoarflPesolAluuteiorn Prevention and Toxics U4W0.1Sas.hMEinnSgvttiroreonen,tmDSe.WCnt.al20P4r6ot0ection Agency Contain WOce/ r\.) XrTo Re: Serum Half-Life of Perfluorooctane Sulfonate Dear Mr. Auer: This will summarize the discussion during our conference call on March 19, 2001 with you, Oscar Hernandez, Michael Santoro and me regarding new information obtained as part of the ongoing serum half-life study on PFOS. Adsinuisftleffyiorcoinumualttkdetnao(toPaiwnFst,Oeet3rSsMp.)rei3hntM.asseThrbhuaeesmeyncdooanoftttrnieenmotuitrpeecdtdoinrtwrgoootsbrotokucredaarytlsce.tuholWiuasrteeisphsaruaihoevra.elcfCpa-lrluicefruverlieafonotutirolsylpnyesar.rvfealpuilooarrbtoeloedcdtoaanntatewaroe ORRE! 85010000013 85010000013 In January 1999, 3M provided EPA with limited data from 3 workers indicating a half-life for PFOS in retired workers' serum of approximately 1,400 days. 3M had in progress a larger study, and on July 15, 2000, submitted the first interim report on serum half life of PFOS among 27 retired employees. These employees had worked at 3M's Decatur. Alabama and Cottage Grove, Minnesota manufacturing plants. This initial analysis of the 27 retirees used data points collected in November 1998, mMoadye1l,9t9h9eamnedaNnosveerummbehral1f9l9if9e, ddeetseigrmnaitneeddtfoo, rfi1a8nodftt2h-eU2s7inegmapolonyee-ceosmwpaasr3tm03ent days (range 139 - 640 days). The remaining 9 employees either had less than three data points or did not show a trend. The 303 days was near the serum half life that f'-O CT, cr cin sp o ron :.: .y or-nR was initially reported for cynomolgus primates (274 days). Although we were aware of several limitations in this study, 3M considered the interim data to be an improvement over our previous estimate, based on only 3 employees, and using varying analytic techniques for determining PFOS. However, the Interim Report advised caution in interpreting the limited data set. rTaSenehtrauiuslrymncteaicdwutsaseeescdvhceunorsliaqleltuocmetreoeednxetxhihnaisbmMiltiasnateeyvrao2ra0fina0sdbo0iuslfhirotcoyrewsaoefofdo2fur0ererttsrhouolrd3tsa0int%ianthcpwoeonhilnsaeitnbsoOtterhbna)et.toswrIanyimtihmteiateslhaaaosmunserapelleymexspieissnecwt.taedTs .he AMPaprgr. eiCl 22h5ar,2le0s0A1uer armaenlledoasutashcumeerrpeetdrlyerpoasrtefsdroofiffrmfoeemrrorenontreht,istasuinmsbdojeuemcrpctuoedil.ntuitprsli.engTanohaneleybsaeisnstaowlyfattiyhcetrousanrm.edeRuscaaenmdthopimlsevecararrnioarbbseirliuetpsyeridesstetoontrun Nine of the 27 subjects, representing a range of PFOS values, were selected for reanalysis. samples for Triplicate analysis each subject were was done for all analyzed during otinmeeapnoailnyttisc(trounth.roInugthhits3w). aAy,ll controllable sources of variability were reduced. Preliminary analysis of these data does not corroborate the range for serum half life reported in the first Interim Report. The data from these nine subjects for linifteernperaerta1t5io0n0 odfatyhse, bduattaw. e are still exploring tvoatrhiroouusgihsstu3 essugthgaetstcoanmfoiunnimdum h alf Other factors complicating assessment of the serum half-life in retired workers may kvatcienhuxnaiancrpdrtlreyoutetmishdinnuceetagsryceOtlahaebrdcleveectueoupcrmlblosoiane.snetrgsticAiaoe2btbnhnt0loeett0nrhl0pisoaiztrrstuedieopddprsnaryoetif-;niootdncroOtePer,pvFEtodaehOCnlifeufSdoDfecietscdahnIuuuesntlr,hrtititioysofniilaunngudllcdoetaAehrrdbisoetvmsehcisehneoctsuegnoswmdmniasoyshiveri;cdeeknaordeetlnarsriiggessnfedorbabiovpcenomagopgtlanhruonnocec3polstcuMnrhuisi-eafpio'vtstacseehtct.IuieuneodNtpseneytlaeariimitmwiltimhoeaiitnxenthRrepaaselott.iphsouoenrrte tWhaet,phlaonwteovesru,bims ittoacsoellceocntddaintatefroimr arpepeorirotdinotfhaet sleuamstmtewrooyfe2a0r0s1a.ndOpurospsliabnlyafltoenrger before doing any more analysis, which will then be done in such a way as to reduce laboratory variability as much as possible. Although this type of study continues to carry many limitations, it remains a good ohpigphoerrtuthnaitnytthoomseeaosbusreervheudminannsoenr-uomccuhpaalftiloifnea, lalylbeexitpaotsceodnicnednitvriadtuioanlss. many times Please do not hesitate to contact me if you have any questions. Very truly yours, Medical Director c: MMrr.. MOsiccahraHeleSrannatnodreoz