In several industrial environments, mechanical risks are often combined with various contaminants such as oils and greases, which may reduce the performance of protective gloves against mechanical hazards. However, glove properties are characterized on new and clean specimens, and little is known about their residual resistance once contaminated and over time. In this study, a series of protective gloves used in metalworking companies and garages were exposed to relevant oils and greases. Used gloves were also obtained from a food processing center and a garage. Their residual resistance to mechanical risks (cutting, puncture and tearing) was evaluated using standard test methods. Results revealed in some instances a large decrease in resistance to mechanical risks. Since a corresponding change in the material aspect may not always be easily observable, this may lead to serious safety breaches. These findings demonstrate the need to further the research in this domain.