The Bureau of Mines investigated fumes generated by selected welding materials used in mines in order to help determine their relative hazard potential. The initial phases of the study have been completed. A welding-fume generation and collection apparatus was designed, assembled, and calibrated. Five brands of coated, aws- type e308-16 stainless steel electrodes were tested. Total fume generation rates of 0.39 to 0.51 G/min were measured. Quantitative chemical analyses were conducted for all of the principal fume constituents. Two analytical schemes were used to determine levels of the cr6+ and cr3+ species contained in the welding fumes; comparable results were obtained. The cr6+ was found to be the most hazardous constituent, leading to a maximum allowable total fume exposure of 1 mg/m3. Fume generation rates and fume constituent analyses will be derived for other groups of welding electrodes using similar procedures.