A method for monitoring dermal exposure to volatile chemicals

Absorptive pads of charcoal cloth were developed and tested for monitoring the deposition of volatile toxic materials on skin. The dosimeters can retain over 60% of volatile deposits such as toluene or dichloropropene droplets over an 8-hr workday. Evaporation from liquid deposits and vapor adsorption onto the dosimeters are factors which can complicate the interpretation of exposure data. Evaporation was inversely proportional to the log of the deposit size (volume), vapor pressure, and the air humidity. Vapor adsorption was proportional to the vapor concentration, exposure duration, and the log of air velocity. A procedure is offered for estimating the initial size of the liquid deposit from retained mass. The charcoal cloth dosimeter's accuracy and precision are optimal in situations involving possible dermal exposure to toxic materials with low to moderate volatility or with low vapor concentration, i.e., those where dermal exposure may be equal to or more significant than respiratory exposure.