Petroleum hydrocarbon toxicity studies: VII. Animal and human response to vapors of “70 Solvent”

Abstract

The suggested hygienic standard for human inhalation of “70 Solvent”, based upon the results of inhalation studies with rats and dogs and the sensory response of human subjects, is 0.32 mg/liter (59 ppm). Inhalation of 4.4 mg/liter (810 ppm) for 8 hr caused lacrimation, loss of coordination, and fine tremors but no deaths among 10 rats. During the 4-hr inhalation of 5 mg/liter (930 ppm), a beagle had convulsions in 2 hr and died 1.5 hr subsequent to the exposure. Four cats that inhaled 2.0 mg/liter (370 ppm) for 6 hr had signs indicative of central nervous system effect. At a concentration of 2.2 mg/liter (410 ppm) body weights of rats and dogs were slightly depressed only after the 13 th week of inhalation. The adjacent level, 1.1 mg/liter (200 ppm), was considered the no-ill-effect level for both species. The odor threshold, as determined by a sniff test involving six human subjects, is approximately 0.004 mg/liter (0.7 ppm). Only minimal responses were elicited by the six subjects during a 15-min period in 0.32 mg/liter (59 ppm) while, at 0.95 mg/liter (180 ppm), ocular and nasal irritation was reported by five and three subjects, respectively. Therefore, a concentration of 0.32 mg/liter (59 ppm) should be tolerated by most individuals.