CHROMIUM, NICKEL AND MANGANESE IN SHIPYARD WELDING FUMES

Tests were conducted to determine the effects of base metal and weldin g electrode composition on welding fume. Materials included HY-100 and HSLA-100 high-strength, low-alloy steels. Shielded metal are welding (SMAW) was performed with E11018-M electrodes and gas metal are weldin g (GMAW) with MIL-100S-1 electrode wire. These tests included measurem ent of fume composition, fume generation rates and worker breathing zo ne fume. Sampling of welding fume also was conducted in a shipyard. Th is study concludes that some shipyard welding and cutting operations, materials and processes will be impacted by the recent and anticipated reductions in exposure limits. Additional controls will be required t o comply with these reductions. Results indicate: Exposure to hexavale nt chromium can be expected when welding or cutting materials that con tain chromium or chromates. These materials include stainless steels, high-chromium nickel alloys and some low-alloy steels. The highest nic kel levels occurred during SMAW and GMAW of stainless steels and nicke l alloys. However, only the samples in enclosed spaces exceeded the pr oposed limit for nickel. SMAW, GMAW and flux cored are welding (FCAW) of stainless steels, carbon steels and low-alloy steels produced the h ighest manganese levels. Eight-hour TWA levels of hexavalent chromium of up to 1-2 mu g/m(3) were found during shipyard and laboratory sampl ing of SMAW of HY-100 using E11018-M and E12018-M electrodes. Similar levels also may be possible when welding with these electrodes on othe r materials.