U.S. Department of Labor
Occupational Safety and Health Administration
Directorate of Technical Support and Emergency Management
Office of Science and Technology Assessment
Introduction
Many electric power plants now use hydrogen gas-cooled electric generators versus air- or water-cooled generators. To prevent injury or fatality, employers must ensure hydrogen gas is completely purged from generator housings and bushing boxes before conducting preventive, predictive, or emergency maintenance (29 CFR 1910.146). Employers should include all manufacturer recommendations in written purging procedures.
