A comprehensive study to determine the biologic threshold limit value of toluene (108883) utilizing the breath analysis decay curve (BADC) was conducted. Twenty healthy adults were exposed to vapor concentrations in an environmentally controlled chamber. The exposure consisted of both steady nonfluctuating concentrations as well as widely fluctuating concentrations. Eleven male subjects were exposed to 0, 20, 50, and 100ppm toluene for 1, 3 or 7.5 hr. Female subjects were exposed to 100ppm for 1, 3 or 7.5 hr. Breath and urine samples were taken. Neurological studies, cardiopulmonary function tests, and cognitive testing were performed. Subjects exposed to toluene at 100ppm for 7.5 hr/day, 5 day/wk demonstrated deleterious effects on visual-evoked-response, increased errors in an alertness test and irritation of the nasal-mucosa. Subjects at 100ppm 3 hr/day, 5 day/wk noted an increase in eye, nose, and throat irritation. Blood-levels were relatively constant at exposures of 50 and 100ppm. Hippuric-acid (495692) excretion increased in a dose dependent manner. The biologic threshold limit value for toluene workers is suggested to be the upper limit of the range of BADC of those exposed 7.5 hr/day for 5 days.
NIOSH-Contract; Contract-099-72-0084; Organic-solvents; Aromatic-hydrocarbons; Testing; Standards; Organic-vapors; Vapor-volume; Vision-test; Visual-stimulation; Visual-performance; Biological-sampling; Sampling; Behavioral-tests; Respiratory-irritants; Irritants; Eye-irritants; Urinalysis; Blood-sampling; Blood-tests