Welding and cutting present a variety of hazards. The main safety issues with arc processes are electrical, IR and UV radiation, generation of fume and gas, hot metal, inert and compressed shielding gases, noise, and thoriated electrodes.
With fuel gas processes the main concerns are flammable or explosive gases and gas mixtures, naked flames, heat, IR radiation, and maybe some fume.
Power beam processes, such as lasers, give hazards associated with high voltage equipment and intense focussed heat sources, in addition to the more usual heat and fume problems.
Thermal and plasma spraying processes give rise to dust, fume, and noise, as well as electrical, fuel gas, compressed gas, or radiation hazards depending on the specific process being used.
In addition to these process specific hazards there are general hazards presented by poor housekeeping, during manual handling, material movement and positioning, by the presence of solvents, other chemicals, or flammable materials in the work area.
All the above hazards may be exacerbated when working in confined spaces, in hot, wet, cramped areas, or if working at height.