Gloves should not be assumed to provide full protection to laboratory workers. When working with hazardous materials, gloves should be discarded immediately following overt contamination; gloves should not be reused. Because of the potential hazard associated with exposure to chemical carcinogens, a program to investigate the permeability of laboratory gloves to carcinogens was initiated. The results obtained when gloves were exposed to solutions of nitrosamines demonstrated that the solvent could facilitate the penetration of the nitrosamine. Since some solvents are very commonly used and some are skin penetrants, which gloves should be used (or avoided) when employing selected solvents was determined. Overall, the polyvinyl-alcohol glove material gave the best performance, polyvinylchloride the worst.