Document dDxDXeGd9LOVOrG47XQLv7re9

PUBLIC COPY May 12, 2009 Via Federal Express Document Processing Center (Mail Code 7407M) Room 6428 Attention: 8(e) Coordinator Office of Pollution Prevention and Toxics U.S. Environmental Protection Agency 1201 Constitution Ave., NW Washington, DC 20004 Dear 8(e) Coordinator: 8EHQ-06-16436/8EHQ-06-16478 Perfluorinated Aliphatic Carboxylic Acid, Ammonium Salt This letter is to inform you of the results of an acute inhalation toxicity study with the R&D test substance referenced above. One group of one male and one female rat was exposed to air only, 2 groups of 3 male and 3 female rats were exposed to aerosol concentrations of 13 or 100 mg/m3 of the test substance in air and a group of 5 male and 5 female rats were exposed to 5,200 mg/m3 of the test substance. Aerosol atmospheres were generated by nebulization, and concentrations of the test substance were measured by gravimetric analysis. The ammonia vapor concentration was monitored with Draeger tubes. The ammonia concentration measured during the 0 and 13 mg/m3exposures was less than 1 ppm. During the 100 and 5,200 mg/m3 exposures the ammonia concentrations were 21 ppm and 960 ppm, respectively. Rats in the control, 13 and 100 mg/m3 were weighed and observed for clinical signs of toxicity during a 2day recovery period Rats in the 5,200 mg/m3 exposure group were weighed and observed for clinical signs of toxicity during a 14-day recovery period. Gross examinations were performed on all rats, and respiratory tract tissues (lung, larynx/pharynx, trachea, and nose) from the control, 13 and 100mg/m3 groups were evaluated microscopically. Respiratory tract tissues from the 5,200 mg/m3 exposure group were not examined microscopically. No deaths occurred in any exposure group and there were no toxicologically significant clinical signs, gross pathological or microscopic findings in any rats from any exposure group. There were no statistically significant body weight losses in the 13 and 100 mg/m3 exposure groups when compared to that of the control rats. Rats in the 5,200 mg/m3 exposure group lost from 2.5 to 6.8% of their original body weight for 1 or 2 days post exposure. Under the conditions of this study, the no observable effect level for clinical signs, body-weight effects, gross pathology, and respiratory pathology in rats exposed to aerosol of the test substance was 100 mg/m3. The 4-hour inhalation median lethal concentration (LC50) for aerosols of the test substance in male and female rats was greater than 5,200 mg/m3. 89090000263/S Sincerely, Com pany Sanitized