Document b64X4OB24M8Z6VbBJ0VRMvL6

BACK TO MAIN BIODEGRADATION (Aerobic Soil and Sediment Cultures) TEST SUBSTANCE Identity: Perfluorooctanesulfonate; may also be referred to as PFOS or FC-95. (1-Octanesulfonic acid, 1,1,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8heptadecafluoro-, potassium salt, CAS # 2795-39-3) Remarks: The 3M production lot number was 217 (TN-A-2130). The test substance is a white powder. Sample was stored AT 16-20oC prior to testing. Purity determined to be 86.9% by LC/MS, 1H-HMR, 19F-NMR and elemental analyses techniques subsequent to analyses cited in the attached report. METHOD Method: Designed by Springborn Laboratories, Inc. Test Type: Aerobic GLP: No Year completed: 2000 Contact time: 20-weeks Inoculum sources: Soils collected from a hardwood forest in Hanson, MA, a pine forest on Onset, MA and a river bank in Bridgewater, MA. Sediments collected from brackish sites below the Wareham, MA wastewater treatment plant outfall and from the Narrows area in Wareham, MA. Biomass was determined on day 83 by both the fumigation/extraction and standard plate count methods. Biomass was reported as 17.4 mg C/100 g soil and 6 x 105 cells/g, respectively. Test medium: Soil and sediment samples were air dried, 2.00 mm sieved, and mixed together in equal dry weight portions. A nutrient mixture was prepared by combining a sterile potting soil extract, a trace mineral solution, a yeast extract and reagent water. The soil/sediment mixture was adjusted to 75% of the water holding capacity using the above nutrient mixture. Soil moisture was monitored weekly during the study, and adjusted using reagent water as needed. Test concentration: ~21.2 mg/kg (nominal) Study design: Inoculum control: soil/sediment mixture, nutrient mixture, methanol Test: soil/sediment mixture, nutrient mixture, PFOS stock solution Incubation conditions Temperature: 22 + 3C Lighting: Conducted in the dark Agitation: Not noted BACK TO MAIN Test vessels: 40 mL I-Chem glass vials with silicone/Teflon-lined septum screw caps containing 10 g (dry weight) soil/sediment mixture. Dosing procedure: Each test flask received all components at test initiation. Sampling frequency: Days 7,14, 21, 28, 35, 42, 49, 56, 63 Analytical method: Entire sample extracted with methanol via accelerated solvent extraction. Extracts passed through a 0.2 m nylon filter prior to analysis. Samples diluted as necessary in methanol, and analyzed via LC/MS. Remarks: Stock solution used to dose the biodegradation test systems was prepared at a concentration of 1,060 mg/L. This concentration is approximately twice the water solubility of PFOS RESULTS Results of PFOS analyses indicated that essentially no PFOS metabolism occurred during the study. CONCLUSIONS PFOS is recalcitrant in the soil/sediment system. DATA QUALITY Reliability: Klimisch ranking = 2. Study not conducted following Good Laboratory Practice Standards. The stock solution used to dose the systems was prepared at twice the water solubility. No Day 0 samples were taken to determine starting concentrations . REFERENCES This study was conducted at Springborn Laboratories, Inc., Wareham, Massachusetts at the request of the 3M Company. Report completed 10/31/00. Lab Project number E01-0434. OTHER Last changed: 5/26/01