Occupational safety and health

Welding is associated with hazards that can result from the use of electric current, pressurized gases, heat, and the release of optical radiation and hazardous substances. The hazards depend on which welding process is used.
Hazardous substances in the form of welding fumes and gases are released from the molten metal - especially from melting filler metals. Metal vaporizes as a result of overheating of the melt or the filler metal. The vapor rises above the melt, cools and forms metal particles by condensation. Airborne metal particles are referred to as welding fume. The composition of the fume depends on the composition of the materials being welded. Fumes released during the welding of non-alloy and low-alloy steels consist mainly of iron and manganese or their oxides. When welding aluminum materials, the fumes consist primarily of aluminum oxides, and welding corrosion-resistant stainless steel releases nickel and chromium compounds. Inhaled iron and aluminum compounds can stress the respiratory tract and impair lung function. Acute poisoning from inhalation of dusts with a very high manganese content can lead to inflammatory reactions in the lungs.