Identifies the hazards to persons entering and working in confined spaces and sets out the precautions to be taken to prevent occupational injuries and fatalities associated with such work environments. Requirements cover personnel, training, first aid, atmospheric testing, entry authorization and precautions to be observed during occupancy. Appendices include general design considerations, an example of an entry permit, listing those aspects most likely to warrant attention/authorization, and additional guidelines for particular tasks which may be hazardous when undertaken in confined spaces (e.g. welding, cleaning).