Document 8O035zzV8XrNvQpg6GR3QMQMe

BACK TO MAIN STABILITY IN WATER (PHOTOLYSIS) TEST SUBSTANCE_______________ Identity: Perfluorooctanesulfonate-potassium salt. May also be referred to as: PFOS, PFOSpotassium salt, 1-Perfluorooctanesulfonic acid-potassium salt, or 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-potassium salt. CAS: #2795 39-3. Remarks: 3M production lot number 171. Test substance is a light-colored powder at 25C. Purity determined to be 86.4% by LC/MS, 1H-HMR, 19F-NMR and elemental analyses techniques. METHOD References: Based on OPPTS: 835.5270 and OECD Draft Document "Phototransformation of Chemicals in Water - Direct and Indirect Photolysis", August 2000. GLP (Y/N): No, but many GLP procedures were employed. Year completed: 2001 Type: Direct and Indirect Photolysis Light source: Suntest CPS+ or Suntest XLS+ lamp Light intensity: 680 w/m2 Wavelength range: 290-800 nm Duration: 67-167 hours Test matrices: Direct: Water Indirect: H2O2/water (1:1 molar equivalent) Fe2O3/water (Fe3+ at 24X molar excess) Fe2O3/water with H2O2 Commercial (Aldrich) humic material prepared as in OPPTS 835.5270 All tests included a series of unexposed controls (kept in the dark) for the evaluation of any degradation reactions occurring without the presence of light. Temperature: 25 + 3C Test sample preparation: Aliquots of PFOS were added to three separate sets of VOA screw cap vials (exposed, unexposed, and control vials) containing 5 ml of appropriate matrix. Test vials were placed in the photoreactor. Control vials were wrapped in aluminum foil, sealed in a plastic bag, and placed in the photoreacter. Analytical Procedures: A UV/Vis spectrum of a saturated aqueous solution of PFOS was recorded between 190 and 110 nm. Samples were analyzed by quantitative LC/MS and GC/MS techniques. RESULTS Degradation and breakdown products: No evidence of direct or indirect photolysis of PFOS was observed under any of the conditions tested. Direct photolytic decomposition of PFOS was not observed based on loss of starting material, nor were any of the predicted degradation products detected above their limits of quantitation. 1 BACK TO MAIN Data obtained from the Fe2O3 matrix samples (with and without H2O2) were pooled to provide sufficient statistical data to estimate the minimum half-life. The mean and standard deviation of these data indicate that the minimum environmental half-life of PFOS due to indirect photolysis at 25C is greater than 3.7 years. CONCLUSIONS No evidence of direct or indirect photolysis of PFOS was observed under any of the conditions tested. The mean and standard deviation of the observed PFOS concentrations in an aqueous Fe2O3/H2O2 matrix indicate that the indirect photolytic half-life of PFOS at 25C is greater than 3.7 years. Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133 DATA QUALITY Reliability: Remarks: Klimisch ranking: 2 Study was well conducted, though not under GLP. REFERENCES This study was conducted at the 3M Environmental Laboratory under Lab Request Number W2775. See 3M Environmental Laboratory Report No. W2775 (dated April 23, 2001). OTHER Last Changed: June 22, 2001 2