Document 8zd4jdYa496382yNNq93O9aB

BACK TO MAIN STABILITY IN WATER (HYDROLYSIS) TEST SUBSTANCE__________________ Identity: N-methylperfluorooctane sulfonamidoethanol; may also be referred to as 2(N-Methylperfluoroctanesulfonamido)-ethyl alcohol, N-MeFOSE Alcohol, FC-790, or FM-3925. (1-Octanesulfonamide, N-methyl1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-heptadecafluoro-N-(2-hydroxyethyl)-, CAS # 24448-09-7). Remarks: 3M production lot number was not noted. The test substance is an amber waxy solid at 25C. METHOD Method: GLP (Y/N): Year completed: Type: Based on OPPTS: 835.2110 No, but many GPL procedures followed. 2001 Hydrolysis as a function of pH Test sample preparation: Test solutions consisted of 1.0 mL of buffered aqueous solutions at six pH levels (1.5, 3.0, 5.0, 7.0, 9.0, and 11.0). The W-MeFOSE alcohol concentration in all test samples (sample duplicates and matrix spike samples) was approximately 473 pg/L. Samples were shielded from light during incubation at 50 for periods of 0 to 49 days. Control samples and blanks addressed potential non-hydrolytic degradation routes. Analytical Procedures: All samples were analyzed using HPLC/MS. Remarks: This study was conducted at 50C in order to facilitate hydrolysis. Rates measured 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 formation of PFOS observed. Degradation: Two independent methods were used to estimate the hydrolytic half-life of W-MeFOSE alcohol. In the first method, direct observations of W-MeFOSE alcohol concentrations show that the loss of W-MeFOSE alcohol is independent of pH. Data over all pH ranges were therefore pooled to provide an estimated range for the pseudo first-order half-life of W-MeFOSE alcohol. In the second method, direct measurements of both W-MeFOSE and PFOS were taken into account. The minimum pseudo first-order hydrolytic half-life of W-MeFOSE alcohol was calculated by estimating how fast W-MeFOSE alcohol or other degradation 1 BACK TO MAIN products might degrade to generate PFOS. This estimate assumes that PFOS is the only hydrolytic product of W-MeFOSE alcohol and that the hydrolysis is independent of pH. The study did not firmly establish the limit of detection (LOD) for PFOS, so these calculations were based on the measured initial W-MeFOSE alcohol concentration and the calculated limit of quantification (LOQ) for PFOS. The two half-life estimates are presented below. Mathematical Method/Quantities Employed Least Squares Log-Concentration Slope Estimate W-MeFOSE alcohol Initial Concentration and LOQ of PFOS Hydrolytic Half-Life at 25C (years) 6.3 > 27 CONCLUSIONS Based on the observed loss of W-MeFOSE alcohol the hydrolytic half-life can be estimated at approximately 6.3 years. An alternative calculation considering the initial N-MeFOSE alcohol concentration and the LOQ of the potential product PFOS yields a hydrolytic half-life greater than 27 years. Submitter: 3M Company, Environmental Laboratory, P.O. Box 3331, St Paul, Minnesota, 55133 DATA QUALITY____________________________________________ Reliability: Klimisch ranking: 2 Remarks: Study was well conducted, though not under GLP. 2 BACK TO MAIN REFERENCES This study was conducted at the 3M Environmental Laboratory under Lab Request Number W1880. See 3M Environmental Laboratory Report No. W1880 (dated March 30, 2001). OTHER Last Changed: June 21, 2001 3