The permeability of protective clothing materials to benzene vapor

The permeability coefficient of benzene vapor in air was calculated from experimentally measured values of solubility coefficient and diffusion coefficient for natural rubber, nitrile, neoprene, natural rubber plus neoprene, butyl rubber, polyvinyl chloride and polyethylene membranes. The permeability coefficient for natural rubber at room temperature (approximately 23 degrees C) was 4.2 x 10(-10) cm2/sec when the concentration of benzene in air was 10 ppm. This means that a worker (1.8 m2 surface area) completely clothed in a 0.0254 cm (10 mil) natural rubber suit would be exposed via the skin to 0.3 microgram benzene in an 8-hour shift if the benzene concentration were 10 ppm. In the same time period and with the same benzene concentration the worker would inhale 1600 microgram benzene if his tidal volume were 700 cm3, his breathing rate were 15 min-1, and he was wearing a respiratory with a protection factor of 100. Permeability coefficients for other vapor-membrane systems available in the literature suggest that exposure to vapors penetrating protective garments are in general negligible when compared with inhalation exposures for low vapor concentrations.