Description
Fuels used include acetylene, methylacetylene-propadiene (MAPP), propane, butane, and hydrogen. Metal fumes of concern in oxy-fuel welding are lead, zinc, and cadmium. These metals have low melting points, and significant vapor pressures occur at the lower temperatures reached in gas welding relative to arc welding. Nitrogen dioxide is a hazard of gas welding in a confined space. In the past, phosphine was found to contaminate acetylene fuel. [Burgess, 186-188]