Results are presented of research intended to assist NIOSH in the development of criteria and performance standards for specific types of protective clothing to be used in various industrial/occupational areas. The results show that mechanical, thermal, chemical, radiological, electrical, and biological hazards, in descending order, account for the highest incidence of injuries. Some protective clothing used for chemical and thermal protection can contribute to heat stress situations by trapping the body heat of workers. Some types of protective clothing, especially high temperature exposure clothing, is bulky to wear and interferes with worker mobility. A large percentage of the industry does not supply or does not stress protective clothing usage.