Document pp1dO3pz5pKjpZNNpe1dk5vgX

BACK BIODEGRADATION TEST SUBSTANCE Identity: Remarks: Perfluorooctanoic acid, ammonium salt; may also be referred to as PFOA, PFOA ammonium salt, Ammonium perfluorooctanoate, FC-116, FC-126, FC-169, or FC-143. (Octanoic acid, pentadecafluoro-, ammonium salt, CAS # 3825-26-1) PFOA was a white powder originally from 3M production lot number 332. An Interim Certificate of Analysis, reports the purity to be 95.2%. All results in this study were calculated assuming 100% purity. METHOD: Method: Based on EPA Guidelines OPPTS 835.3200 Test Type: Aerobic GLP: No, but many GLP procedures followed. Year Completed: 2001 Contact time: 18 days Inoculum: Activated sludge collected 7/31/00 from the aeration basin at the Metro Wastewater Treatment Plant, St Paul, MN. The MLSS was determined to be 2,280 mg/L when first collected. The mixed liquor suspended solids, MLSS, was stored at 4 C for approximately 5 weeks prior to being used for this study. The sludge was allowed to settle and the solids used for inoculum. The settled sludge constituted approximately 20% of the volume (~200 mL) of the MLSS used. Test medium: Test flasks were prepared using a mineral salts medium defined in EPA Guideline OPPTS 835.3200. Methanol (1 mL per liter) was added per liter of mineral medium. Fifty mL of settled sludge was added per liter of mineral salts medium. Mineral medium plus sludge was prepared 9/7/00, while fresh mineral medium without sludge (abiotic controls) was prepared 8/10/00. Study design: Blank Sludge Controls (mineral medium, inoculum) Abiotic Controls (mineral medium, PFOA) Test Substance (mineral medium, inoculum, PFOA) Test vessels were set in duplicate. Additional quality control samples (blanks) were prepared and analyzed as appropriate. Test concentrations: 2.645 mg/L of PFOA. Incubation condition: Temperature: 25oC +/- 3oC Agitation: ~200 rpm Test vessels: Sterile 125 mL Nalgene polycarbonate culture flasks containing 25 mL of media Dosing procedure: Test vessels were spiked with 6 pL of an 11,020 mg/L solution of PFOA in methanol yielding 2.645 mg/L. Sampling Frequency: Days 0 and 18. Analytical method: The day zero test vessels were prepared and immediately placed in a freezer that was maintained at -20oC until analyzed. After 18 days, the test vessels were removed from the incubator and frozen until final sample preparation by solid phase extraction (SPE). Following thawing, test vessel contents were adjusted to 1% acetic acid BACK and then passed through a conditioned SEP-VAC C18 6cc SPE cartridge. Methanol was then added to the emptied culture flask, shaken vigorously and then passed through the SPE cartridge to extract adsorbed analytes. A second methanol wash was collected separately for analysis to ensure quantitative extraction. Quantitative analysis was conducted on an HP1100 high performance liquid chromatograph with mass spectrometer detector (HPLC/MSD) system. The MSD was operated in electrospray ionization in negative-ion mode using selected-ion monitoring (SIM) for quantitation. In addition to the parent, PFOA, the compounds listed below were quantified. In the case of the compounds that are potassium or ammonia salts, only the concentration of the fluorochemical anion was quantified and reported. Compound Name Acronym Chemical Formula 2-(N-Ethyl Perfluorooctane sulfonamido) acetic acid N-EtFOSAA C8FiySO2N(C2Ha)(CH2COOH) 2-(Perfluorooctane sulfonamido) acetic acid M556 C8FiySO2NH(CH2COOH) N-Ethyl Perfluorooctane sulfonamide N-EtFOSA C8Fi7SO2NH(C2H5) Perfluorooctane sulfonamide FOSA C8F17SO2NH2 Perfluorooctane sulfinate, potassium salt PFOSulfinate C8F17SO2" K+ Perfluorooctane sulfonate potassium salt PFOS C8F7SO3- K+ Reference substance: None. When results from an EtFOSE Alcohol study conducted at the same time are compared to the previous EtFOSE Alcohol 35-day study, the viability of the microbial inoculum is confirmed. RESULTS__________________________________________________ 1 After 18 days, the analytical results demonstrate that when exposed to municipal wastewater treatment sludge, 2.645 mg/L PFOA was not measurably degraded biotically or abiotically. None of the target analytes was observed. Mass balance for PFOA test vessels was excellent and ranged from 103 - 107%. BACK CONCLUSIONS No loss of PFOA was demonstrated. The results from this study confirm the results from other aerobic biodegradation studies of PFOA. DATA QUALITY Klimisch ranking = 2. The study was conducted as a non-GLP study but with the understanding that good data quality objectives be met. Determination of analyte recovery from spiked sample matrices was not deemed necessary as they have been determined twice previously at several different concentrations, and in both instances recoveries were near 100% with some exceptions for M556. Methanol and sample (mineral medium) blanks contained no detected target analytes. Analyses of the blank sludge controls (mineral media plus inoculum) at days 0 and 18 demonstrated that the inoculum source did not contain endogenous concentrations of test substance. A calculation error was discovered subsequent to the issuance of the final report. The PFOS molar conversion calculation should have used 538 ng/nmole rather than 522 ng/nmole. The corrected value for PFOS on page 13 of the report should be 92.9 nM. This does not affect any of the reported results or conclusions. REFERENCES______________________________________________ 1Biodegradation Study Report, "The 18-Day Aerobic Biodegradation Study o f Perfluoroctanesulfonyl-BasedChemistries", Contract Analytical Project ID: CA097, February 23, 2001. Conducted at the request of the 3M Company by Pace Analytical Services, Inc., Minneapolis, MN. OTHER Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133 Last changed: 6/21/01