Irritation effects from experimental exposure to n-butyl acetate

The irritation produced by acute exposure to n-butyl acetate in human subjects without any history of occupational solvent exposure was studied in three experiments. Exposure levels tested in the different experiments were 350, 700, 1,050, and 1,400 mg/m3 in 20 min sessions, 70 and 1,400 mg/m3 in 20 min sessions, and 70 and 700 mg/m3 in 4 h sessions. Rating scales, various measures of eye irritation, and pulmonary functions were used to evaluate the irritation produced by the exposures in different parts of the study. The results indicate only very slight irritation from the exposures as revealed by categorical ratings, magnitude estimation, and some of the clinical measures of eye irritation and pulmonary functions, such as eye redness, lipid layer thickness, and bronchial responsiveness. These essentially negative results indicate the need to explore and develop the utility of new/different methods of quantifying irritative effects of exposure to various substances.