Welding, cutting, and brazing operations are major causes of fires in museums today. These operations also pose a serious health threat to workers because they generate toxic fumes and ultraviolet radiation, which can injure the eyes. They present an obvious burn hazard to workers who might come in contact with a hot object or torch as well. This brochure is an overview of the hazards involved in welding, cutting, or brazing and some basic precautions and procedures necessary to prevent injuries and fires. Welding problems vary with the welding methods employed, the location of work, the materials being welded or cut, and the control measures employed. The American Welding Society has identified over eighty different types of welding and associated processes in commercial use. Some of the more common types include oxyacetylene welding, gas metal and gas tungsten arc welding (TIG), sheilded-metal arc welding (MIG), resistance welding, and brazing. With proper environmental controls and work procedures, the hazards associated with welding can be reduced.