The purpose of this publication is to present information concerning the environmental conditions imposed upon workers in industries which require clean room facilities to eliminate particle-caused equipment failure. The information, which was collected through interviews, observation, and other standard job analysis techniques, discusses these topics: (1) history of clean rooms, (2) degrees of cleanliness in clean room installations, (3) industrial use of clean rooms, (4) general working conditions, (5) job requirements, (6) employee qualifications, with respect to interests, temperaments, and aptitudes, (7) selected occupational activities in the aerospace industry and medical apparatus manufacturing plants, including descriptions of nature of work, working conditions, physical demands, entry level training and qualifications requirements, and advancement opportunities for an aerospace assembler and assembler of implantable devices, and (8) employment outlook for clean room occupations. (SB)