| Non-Human Toxicity Excerpts | /LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ In an initial 4-week nose-only inhalation study, male and female rats were exposed 6 hr/day, 5 days/week at concentrations of 0, 2000, 10,000, or 40,000 ppm. Females showed no evidence of toxicity at any exposure levelmale rats did exhibit degenerative changes only in the tests at all exposure levels. However, because of exposure system irregularities, which resulted in excessive temperature conditions and stress in the HFC-143a-exposed groups, the study was repeated in male rats exposed by whole-body inhalation. In this repeat study no toxicity was observed at < or = 40,000 ppm. Moreover, a subsequent 90-day whole-body inhalation study in rats exposed 6 hr/day, 5 days/week at 0, 2000, 10,000, or 40,000 ppm resulted in no evidence of toxicity at any exposure concentration. The results of the second 4-week and the 90-day studies using whole-body exposures indicate that the findings from the first 4-week study were related to the stress induced by excessive temperatures and nose-only restraint. Therefore, the no-observed-effect level (NOEL) for rats repeatedly exposed up to 90 days was considered to be 40,000 ppm./LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ In one study, a 3% solution of 1,1,1-trifluoroethane in corn oil was given to rats (36 of each sex) by gavage in doses of 300 mg/kg body weight, 5 days/week for 52 weeks. The animals were killed on week 125, and routine histopathological examinations of lungs, liver, spleen, kidneys and brain were made, and other organs were also examined if they looked abnormal. Males had significantly lower body weights from week 28 to week 88. No other exposure-related effects were observed: there was no significant increase of cancer incidence in any organ, for example./LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ The present paper summarizes data on the reproductive and developmental toxicity of hydrofluorocarbons (HFCs), including pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1-trifluoroethane (HFC-143a), 1,1-difluoroethane (HFC-152a), difluoromethane (HFC-32) and 1,1,1,3,3-pentafluoropropane (HFC-245fa), used as refrigerants, published in openly available scientific literature. ... No maternal or developmental toxicity was noted after exposure to HFC-143a even at 40,000 ppm in rats or rabbits ... . No evidence of teratogenicity for these HFCs was noted in rats or rabbits./LABORATORY ANIMALS: Developmental or Reproductive Toxicity/ In developmental toxicity studies with rats and rabbits, an increase in visceral variations or skeletal malformations was observed, respectively, at HFC-143a concentrations of 2000, 10,000 or 40,000 ppm (rat) or at the low and high concentrations (rabbit). Because of the unusually low control incidence of variations (1.6% per litter in the control versus 6.8-16.8% for historical control values), the lack of a clear dose-response relationship, and the lack of other developmental effects, these findings were not considered related to HFC-143a exposure. ...For more Non-Human Toxicity Excerpts (Complete) data for 1,1,1-Trifluoroethane (7 total), please visit the HSDB record page. |
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