Abstract
Rats, mice, guinea pigs, and rabbits were exposed repeatedly six hours per day, five days per week for one to three months to the vapors of either 2-nitro-2-butene, 3-nitro-3-hexene, 2-nitro-2-nonene, or 4-nitro-4-nonene. Concentrations of 10 and 20 ppm and relative humidities of approximately 50% and 90% were used. Each material elicited signs typical of a potent irritant of the lower respiratory tract. The effects were more severe at the lower humidity. The hematologic changes are considered to be consistent with secondary polycythemia resulting from changes in the pulmonary epithelium. Central nervous system stimulation was observed only in rabbits exposed to 2-nitro-2-butene and deserves further study.