Influence of evaporation and solvent mixtures on the absorption of toluene and n-butanol in human skin in vitro

The influence of forced ventilation on the percutaneous absorption of butanol and toluene,vas studied in vitro, Human skin was exposed to the neat solvents and the solvents in binary mixtures with each other and in ternary mixtures with chloroform:methanol. The exposure,vas either unventilated or ventilated with various flow rates. At the ventilated exposure the skin absorption of all solvents and solvent mixtures was markedly! reduced compared to unventilated exposure. Exposure with solvent mixtures increased the amounts of solvent absorbed as well as absorption rates. The absorption of the butanol component was most influenced. Increase in absorption was 11 to 9 times depending on whether toluene or chloroform/methanol, was cosolvent, There was also an interindividual variation of absorption rate, varying,with a factor of 3.5 for toluene and 4.3 for n-butanol within the 3 skin donors used. Skin absorption of volatile organic solvents at continuous ventilated conditions is related to their, volatility and to the ventilation rate. A sufficient workplace ventilation is an important occupational hygienic measure not only to reduce exposure cia respiration but to reduce absorption via the skin of volatile compounds as well. (C) 2000 British Occupational Hygiene Society, Published by Elsevier Science Ltd, All rights reserved.