|10 min||30 min||1 h||4 h||8 h|
|160 ppm||160 ppm||80 ppm||20 ppm||10 ppm|
|Reference: E. I. du Pont de Nemours & Co. 1962b. Inhalation Toxicity of Hexafluoroacetone Compound in Rats. Haskell Laboratory report No. 46-62. Haskell Laboratory for Toxicology and Industrial Hygiene, E. I. du Pont de Nemours & Co. Unpublished report.
E. I. du Pont de Nemours & Co. 1962a. Inhalation Toxicity of Hexafluoroacetone Dihydrate in Rats. Haskell Laboratory report No. 47-62. Haskell Laboratory for Toxicology and Industrial Hygiene, E. I. du Pont de Nemours & Co. June 27, 1962. Unpublished report.
|Test Species/Strain/Sex/Number: Rat, ChR-CD, male, 4|
|Exposure Route/Concentrations/Durations: Inhalation; HFA at 100, 200, 300, and 400 ppm (nominal) for 4 h; HFA nonahydrate at 300, 400, 500, and 1,000 ppm (nominal) for 4 h|
|End point/Concentration/Rationale: No lethality observed with HFA at 200 ppm or with HFA nonahydrate at 300 ppm HFA. HFA at 300 ppm resulted in 50% mortality and HFA nonahydrate at 400 ppm resulted in 25% mortality.|
Total uncertainty factor: 10
Interspecies: 3 was applied to account for uncertainties associated with extrapolating animal data to human exposure conditions; no irreversible effects were observed in studies of rats and dogs exposed to HFA at 12 ppm for up to 13 weeks (6 h/day, 5 days/week).
Intraspecies: 3 for intraspecies variability because HFA does not appear to undergo significant metabolism and because a larger factor would result in exposure concentrations below those shown to be nonlethal in multiple-exposure rat and dog studies (E. I. du Pont de Nemours & Co. 1971).
|Modifying factor: None|
|Animal-to-human dosimetric adjustment: Not applicable|
|Time scaling: For the time scaling from the 4-h experimental duration to AEGLspecific durations, the equation Cn × t = k was applied, where n = 1 was determined empirically from available data (ten Berge et al. 1986). Because of the uncertainty in extrapolating a 4-h point of departure to a 10-min exposure duration, the 30-min AEGL-3 value was set equivalent to the 30-min value.|
|Data adequacy: Lethality data were considered adequate for development of AEGL-3 values.|