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p. 1 Katherine E . Reed, Ph .D. 3M Environmental, Health and 900 Bush Avenue, Building 42-2E-26 Staff Vice President Safety Operations PO Box 3333 1 o -~~ A, F.7 ..~ ~ St . Paul, MN 55133-3331 651 778 433 1 3M Certified Mail May 29, 2007 E E H Q- 0 6- I b 6 2 9 Sanitized Company Document Processing Center EPA East - Room 6428 Attn : Section 8(e ) Sanitized Office of Pollution Prevention and Toxics US EP A 1200 Pennsylvania Avenue NW Washington DC 20460-0001 .3 RE : TSCA 8(E) SUBSTANTIAL RISK NOTICE : Supplemental to Docket No . 8EtV06-16629 on [TEST SUBSTANCE] To Whom It May Conce rn : 3M is providing to the EPA results of a marine algal growth inhibition study performed on [TEST SUBSTANCE/ to supplement a previous submission on a related mate ri al, [FLUOROALIPHATIC POLYMERIC ESTERS] . The submission on [FLUOROALIPHA TI was for a marine algal growth inhibition study showing an estimateCPOLYMERISTd] 72 hour EC50 to Skeletonema costatum of 0 .62 mg/1 using the biomass integral an d 3 .24 mg/1 by growth rate calculation . . .~ Results of the current study on [TEST SUBSTANCE] indicate far less toxicity, with an estimated 72 hour EC50 to Skeletonema costatum of 13 mg/1 using the biomass integral and 2 4 mg/1 by growth rate calculation . Based on the compositional differences between the two test :-_ materials, as detailed below, these results suggest the toxicity observ ed with [FL UOROALIPHA TIC POLYMERIC ESTERS] resulted from the [hydrocarbon moiety] component as opposed to the [ luorocarbon moiety] . Test Substance Fluorocarbon moiety]' [Hydrocarbon moiety] NMP [FL UOROALIPHATIC 22% 78% 2% POLYMERIC ESTERS] (98% polymer solids ) [TESTSUBSTANCE] 38% 62% 0% (100% polymer solids) Chemical structures of components provided with the original submission . r The final report for the current study is enclosed. Please contact De an na Luebker at 651-737L 1374 if you have any questions or if we can provide additional information . Sincerely, ~Cc.Zr,L1 .~/1.t.fit /~i C~ ~~G~. C J Katherine E . Reed Staff Vice President, Environmental Health and Safety Operations . .~ Enclosure