The in vitro penetration of [14NC]benzene through freshly prepared human skin was examined under a variety of skin conditions associated with swimming and bathing. The experimental system utilized a recirculating donor solution and a flow-through receiver solution, and was modified to accommodate the analysis of volatiles. The permeability coeffficient of 0.14 cm/h under standard conditions at 26°C was found to increase to 0.26 cm/h at 50°C and decrease to 0.10 cm/h at 15°C. Storage of the skin at −20°C did not affect the penetration of benzene. Application of baby oil, moisturizer, or insect repellant to the skin before exposure under standard conditions did not affect the flux of benzene, but a significant increase was observed when the skin was pretreated with sunscreen (permeability coefficient 0.24 cm/h). These results suggest that risk assessment or exposure modeling for benzene and other environmental contaminants should account for appropriate changes in the environmental conditions when considering the dermal route of exposure.