Document DGyE97k7YMGpRNo4n6QmxGpKd

BACK TO MAIN STABILITY IN WATER (HYDROLYSIS) TEST SUBSTANCE Identity: Remarks: Perfluorooctanesulfonamide; may also be referred to as FOSA or F-10105 (1-Octanesulfonamide, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro, CAS # 754-91-6. 3M production lot number was not noted. Test substance is an off-white waxy solid at 25C. METHOD Method: Based on OPPTS: 835.2110 GLP (Y/N): No, but many GLP procedures followed. Year completed: 2001 Type: Hydrolysis as a function of pH Test sample preparation: Test solutions consisted of 1.0 mL buffered aqueous solutions at six pH levels (1.5, 3.0, 5.0, 7.0, 9.0, and 11.0). The resulting FOSA concentration in all test samples (sample triplicates and matrix spike samples) was approximately 499 mg/L. Samples were shielded from light during incubation at 50 for periods of 0 to 42 days. Control samples and blanks addressed potential non-hydrolytic degradation routes. Analytical Procedures: Samples were analyzed by quantitative HPLC/MS. Remarks: This study was conducted at 50C in order to facilitate hydrolysis. Rates derived at 50C were extrapolated to 25C by dividing by a factor of 10, which is valid for reactions with Arrhenius heats of activation near 18 kcal/mole. RESULTS Breakdown products: No PFOS formation detected. Degradation: Three independent methods were used to estimate the hydrolytic half-life of FOSA. In the first method, direct measurements of FOSA concentrations show no degradation at any pH. Data over all pH ranges were therefore pooled to facilitate the estimation of the pseudo first-order half-life of FOSA. In the second method, direct measurements of both FOSA and PFOS were taken into account. The minimum pseudo first-order hydrolytic half-life of FOSA was estimated using the measured initial FOSA concentration and the established experimental LOQ for PFOS. This estimate assumes that PFOS is the only hydrolytic product of FOSA and that the hydrolysis is independent of pH. In the third method, the initial FOSA concentration and the LOD for PFOS were used to estimate the hydrolytic half-life. The calculation was performed because the sample 1 BACK TO MAIN data indicate that the PFOS LOD was significantly lower than the LOQ determined from the calibration data alone. The three half-life estimates are presented below. Mathematical Method/Quantities Employed FOSA Concentration Mean and Standard Deviation FOSA Initial Concentration and LOQ of PFOS FOSA Initial Concentration and LOD of PFOS Hydrolytic Half-Life at 25C (years) 11 8.3 33 CONCLUSIONS No hydrolytic degradation of FOSA was observed. No formation of PFOS was detected. The result is based on LOQ/LOD and measurement uncertainties. Data collected in this study indicate that the hydrolytic half-life of FOSA in water is greater than 11 years. One alternative calculation considering the PFOS LOQ as well as the initial FOSA concentrations indicates that the FOSA hydrolytic half-life is greater than 8.3 years. A similar calculation based on the PFOS LOD and the initial FOSA concentrations indicates that the FOSA hydrolytic half-life is greater than 33 years. Submitter: 3M Company; Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133. DATA QUALITY Reliability: Klimisch ranking: 2 Remarks: Study was well conducted, though not under GLP. REFERENCES This study was conducted at the 3M Environmental Laboratory under Lab Project Number EL-1132. See 3M Environmental Laboratory Report No. EL-1132 (dated April 3, 2001). OTHER Last Changed: June 21, 2001 2