Comparative inhalation toxicities of four halogenated hydrocarbons to rats and mice in the presence of gasoline fires; carbon tetrachloride, monochloromonobromomethane, difluorodibromomethane, and trifluoromonobromomethane
Comstock, C.C.; Oberst, F.W.
A.M.A. Archives of Industrial Hygiene and Occupational Medicine 7(2): 157-167
1953
ISSN/ISBN: 0096-6703 PMID: 13007212 Document Number: 8547
1. The burning of ½ pt. of gasoline for about 2 minutes in a closed 20-cubicmeter chamber did not produce marked effects on rats and mice exposed for 15 minutes. 2. Approximately 3 lb. of either carbon tetrachloride (CC14), monochloromonobromomethane (CH2C1Br), or difluorodibromomethane (CF2Br2) dispersed as a vapor in the chamber without a gasoline fire was lethal to 5% or less of the animals after 15 minutes of exposure. Trifluoromonobromomethane (CF3Br) in the same amount killed no animals. 3. When a fire was extinguished rapidly by the various agents, the mortality among the animals was somewhat increased over that resulting from the agents alone. CF2Br2 was the most toxic to both rats and mice, while CH2C1Br and CF3Br were about equal in toxicity and were the least toxic. 4. When a fire was extinguished slowly, the mortality among both rats and mice was generally higher than that after a rapid extinction. CF2Br2 was the most toxic to mice, the results varying widely from 37 to 100% mortality in two tests. CCI4 was the most toxic to rats, killing nearly one-third of them within three to nine days after an exposure. CH2C1Br was second in toxicity to both rats and mice. One of the least toxic agents was CF3Br, which produced very few deaths among mice and rats within 14 days after a 15-minute exposure. 5. The CO concentration of the chamber was approximately the same after the use of each agent in extinguishing a gasoline fire under a given condition. When the fire was extinguished slowly, the CO concentration was about 100 times greater than that after a rapid extinction. 6. The chamber concentration of carbonyl halides, determined as phosgene, varied somewhat for the different agents and also for the same agent in different tests. When a fire was extinguished slowly with CC14 and with CH2C1Br, the concentration was approximately 100 times that after a rapid extinction. CF3Br produced only a trace of carbonyl halide, while CH2C1Br produced next to the lowest concentration after a slow extinction. 7. Exophthalmos and pallor Were characteristic of the rats with all four agents when the fire was extinguished slowly. 8. Rats and mice showed congestion of trachea and lungs after exposure to all four compounds in the presence of fire. With CC14 there was also pulmonary edema. In rats, after the use of CC14, there was in addition focal necrosis of the liver.
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