ABSTRACT
Acute exposure studies were conducted using adult male Sprague-Dawley rats to obtain LC50/24 concentrations for the common esters of acrylic and methacrylic acids. The order of acute toxicity was determined to be methyl acrylate greater than ethyl acrylate greater than butyl acrylate greater than butyl methacrylate greater than methyl methacrylate greater than ethyl methacrylate. Four-hour daily exposures (excluding weekends) of young adult male rats to 110 ppm methyl acrylate in air over a period of 32 d failed to produce significant differences in body or tissue weights, blood chemistries, gross metabolic performance, and spontaneous small-intestinal motor activities when compared with a sham-exposed group.
Subject(s)
Acrylates/toxicity , Methacrylates/toxicity , Animals , Body Weight/drug effects , Lethal Dose 50 , Male , Organ Size/drug effects , Rats , Rats, Inbred Strains , VolatilizationABSTRACT
Subacute inhalation experiments were conducted to determine the LC50 value for adult Sprague-Dawley rats exposed to iodoform vapor. Each dose consisted of 5 males and 5 females that were together for a 7-h exposure or sham exposure and then separated for observation over the subsequent 24-h period. The rats were deprived of food and water during actual exposure or sham exposure. Exposures were conducted in a custom-designed 75-l glass chamber. Vapor concentrations were verified in samples taken from the exposure chamber. Under the conditions of the experiments the 7-h LC50 was found to be 183 ppm. The second objective of these experiments was to determine the toxic effect of iodoform vapor on rats exposed for 7 h/d for 7 consecutive days. Three groups of 5 young adult male and 5 female rats were used. One group served as a sham control and the other groups were exposed to 1 and 14 ppm iodoform vapor. No significant differences were noted in food and water intake, urine and feces output, and intestinal transit performance in either exposed group. No remarkable changes were noted in SMA 12/60 blood values for either exposed group. The only histopathological manifestation noted was the presence of mineralized deposits in the medullary renal tubules of some of the rats from the 14-ppm group.
Subject(s)
Hydrocarbons, Iodinated/toxicity , Animals , Blood Chemical Analysis , Female , Hydrocarbons, Iodinated/administration & dosage , Intestines/drug effects , Lethal Dose 50 , Male , Rats , Rats, Inbred Strains , Time FactorsABSTRACT
Acute inhalation experiments were conducted to determine 24-h LC50 values for adult Sprague-Dawley rats of both sexes exposed to vapors of methyl mercaptan and other reduced-S compounds for 4 h periods. Using calculated gas concentrations, the following LC50 value for each gas and combination was determined: metyhl mercaptan, 675 ppm; dimethyl sulfide, 40,250 ppm; dimethyl disulfide, 805 ppm; hydrogen sulfide, 444 ppm; and an equimolar mixture of methyl mercaptan, dimethyl sulfide, and dimethyl disulfide, 550 ppm. The effects of body and tissue weights, gross metabolic performance, O2 consumption, systolic blood pressure, various blood parameters, and intestinal transit time associated with 3-mo exposures of young adult male rats to chemically verified concentrations of 2, 17, and 57 ppm methyl mercaptan vapor are summarized in this report. No mortality was experienced by any group. Histopathological findings were essentially nil except for microscopic suggestions of liver damage. The most readily apparent phenomenon was the decrease in body weight. Average values of terminal body weights for all exposed groups were lower than that for the sham control group. This difference was significant in the 57 ppm group and followed a statistically significant dose-related trend.
