Document k9mp3mRnYBwDZ0qqykb8kOgpy

BACK TO MAIN ACUTE CONTACT TOXICITY TO TERRESTRIAL INVERTEBRATES (HONEY BEE) 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 field: The 3M production lot number was 217. 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. METHOD Method: USEPA OPPTS 850.3020 (draft), OECD Guideline 214, EPPO Guideline 170 Test type: Acute Contact GLP: Yes Year Completed: 2001 Species: Apis mellifera L. Analytical monitoring: None - nominal concentrations Test honey bee source: Obtained from colony number 32 belonging to the Central Science Laboratory (CSL), Sand Hutton, York, UK, National Bee Unit. Test honey bee age at study initiation: Young adult Test honey bee type: Worker honey bees, free of acarine, nosema and amoeba. Varroacide treatment: None within the 4 weeks prior to test initiation. Test conditions Humidity: 65% + 5% Temperature: 25 + 2oC Lighting: Conducted in darkness Stock and test solutions preparation: Test substance: Stock solution prepared in analytical grade acetone to a final concentration of 90.4 gg PFOS/pL (nominal concentration). Final test concentrations prepared in acetone from dilutions of this solution. Reference toxicant: Stock solution of dimethoate was prepared in deionized water containing 1 g/L Triton X-100 to a final BACK TO MAIN concentration of 3.0 Mg/ML. Final test concentrations prepared from dilutions of this solution. Stability of the test chemical solution: A dispersion test was carried out on an 86 Mg PFOS/mL acetone solution before the toxicity study was performed. The homogeneity of the mixture was assessed after 2 hours. The test item formed a clear solution on mixing; after 2 hours at room temperature, slight sediment was noted. For the toxicity test, all solutions were re-mixed prior to use. The contract laboratory considered the solutions of the test doses to be homogenous for the purpose of administration. Exposure vessels: Clean, well-ventilated, inverted petri dishes, measuring approximately 9 cm in diameter. Feeding: 50% w/v aqueous sucrose solution, continuously available Number of replicates: Three Number of bees per replicate: Ten Negative control: Undosed Solvent control: Acetone Reference substance: Dimethoate Reference substance control: Triton X-100 Number of concentrations: five plus a negative and a solvent control Dose administration: The bees were anaesthetized with carbon dioxide immediately before dosing and gently tipped out onto filter paper and counted into the petri dish cage (drones were discarded). Each bee was dosed on the thorax with a 1 mL drop of a given test item concentration or 1mL acetone before being placed into the test chamber. Dose frequency: Once Element basis: Mortality results Nominal concentrations: Negative control, acetone control (1.0 M/bee), 1.93, 4.24, 9.30, 20.5, 45, Mg PFOS/bee Element value and 95% confidence interval : 24-hour LD50 = 38.9 (28.2 - 71.2) Mg/bee 48-hour LD50 = 10.4 (8.2 - 13.0) Mg/bee 72-hour LD50 = 6.0 (4.7 - 7.6) Mg/bee 96-hour LD50= 4.78 (3.8 - 5.8) Mg/bee 96-hour NOEL = 1.93 Mg/bee All element values based on nominal concentrations Statistical Evaluation: Probit mortality plotted against the logarithm of dose using the contract laboratory Probit 1 package. A least-squares BACK TO MAIN regression (Finney 1971) was fitted to these. The NOELs were estimated using Student's t-test (p<0.05) Biological observations: There was significant mortality at all doses above 1.93 gg/bee with a steep dose response between 4.24 and 9.30 gg/bee Cumulative percent mortality:________________________________ Nominal Test Conc., |jg/bee 4-hours 24-hours 48-hours 72-hours 96-hours NegativeControl 0 0 3.3 3.3 3.3 Solvent Control 3.3 3.3 3.3 3.3 3.3 1.93 0 6.7 6.7 13 13 4.24 00 13 37 37 9.30 0 6.7 40 63 90 20.5 0 40 93 97 100 45.0 0 50 93 100 100 Sub-lethal Effects - Percent Knockdown (K) or Stumbling (S): Nominal Test Conc., jg/bee 4-hours 24-hours 48-hours 72-hours 96-hours NegativeControl Solvent Control 1.93 4.24 9.30 20.5 45.0 0 0 3.3(K) 0 0 0 0 0 0 0 0 0 3.3(K) 3.3(K) 0 0 0 0 0 0 3.3(K) 0 0 0 0 0 3.3(K) 0 0 0 0 0 3.3(K) 0 0 Control response: satisfactory Reference toxicant response: satisfactory - dimethoate 96-hour LD50 = 0.19 gg/bee BACK TO MAIN CONCLUSIONS The potassium perfluorooctanesulfonate 96-hour contact LD50for the honey bee was determined to be 4.78 pg/bee with a 95% confidence interval of 3.8 - 5.8. The 96-hour no observed effect level was 1.93 pg/bee. The dose response was steep between 4.24 and 9.30 pg/bee. Submitter: 3M Company, Environmental Laboratory, P.O. Box 33331, St. Paul, Minnesota, 55133 DATA QUALITY Reliability: Klimisch ranking 1 REFERENCES This study was conducted at Central Science Laboratory, Sand Hutton, York, UK, under contract by Wildlife International, Ltd, Easton, MD at the request of the 3M Company, Lab Request Number U2723, 2001. OTHER Last changed: 5/1/01