Document YDw8Kd8JydO3Z7KYa9e9dGgyN

Katherine E. Reed, Ph.D. 3M Environmental, Health and 8&tQ-0(>07- /C.ulStaff Vice President Safety Operations p. 1 900 Bush Avenue, Building 42-2E-26 PO Box 33331 St. Paul, MN 55133-3331 651 778 4331 Certified Mail 8 E H Q - Ob May 29, 2007 Document Processing Center C o m p an y SanifiroH EPA East - Room 6428 Attn: Section 8(e) vU Office of Pollution Prevention and Toxics US EPA 1200 Pennsylvania Avenue NW Washington DC 20460-0001 Sanitized oJ f RE: TSCA 8(E) SUBSTANTIAL RISK NOTICE: Supplemental to Docket No. 8EHQ06-16629 on [TEST SUBSTANCE] To Whom It May Concern: 3M is providing to the EPA results of a marine algal growth inhibition study performed on [TESTSUBSTANCE] to supplement a previous submission on a related material, [FLUOROALIPHATIC POLYMERIC ESTERS]. The submission on [FLUOROALIPHATIC POLYMERIC ESTERS] was for a marine algal growth inhibition study showing an estimated 72 hour EC50to Skeletonema costatum of 0.62 mg/1 using the biomass integral and 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 EC50to Skeletonema costatum of 13 mg/1 using the biomass integral and 24 mg/1 by growth rate calculation. Based on the compositional differences between the two test materials, as detailed below, these results suggest the toxicity observed with [FLUOROALIPHATIC POLYMERIC ESTERS] resulted from the [hydrocarbon moiety] component as opposed to the [fluorocarbon moiety]. Test Substance [F luorocarbon m oiety/' [Hydrocarbon moiety/ [FL UOROALIPHA TIC 22% 78% POLYMERIC ESTERS] (98% polymer solids) [TEST SUBSTANCE] 38% 62% (100% polymer solids) 'Chemical structures of components provided with the original submission. NMP 2% 0% The final report for the current study is enclosed. Please contact Deanna Luebker at 651-737^ 1374 if you have any questions or if we can provide additional information. `, Sincerely, ,A HuJL ( WX) Katherine E. Reed Staff Vice President, Environmental Health and Safety Operations * . Enclosure 89070000290 /