Various methods through which exposure to gallium-arsenide (1303000) might be reduced in the microelectronics industry were discussed. While there were no reported studies showing ill effects in workers from exposure to gallium-arsenide or gallium particulates, three studies in animals indicated that gallium-arsenide dissociates into gallium (7440553) and arsenic (7440382) in biological tissue, the latter being a carcinogen. There was no evidence that gallium- arsenide behaved differently in humans. There were no regulations governing exposure levels for gallium-arsenide or gallium. NIOSH Recommended Exposure Limit (REL) for arsenic was 2 micrograms/cubic meter air (microg/m3). NIOSH recommends control of worker exposure to gallium-arsenide by observing NIOSH REL for inorganic arsenic, and that concentration of gallium-arsenide in air be estimated by determining arsenic. Workers should be educated in possible hazards connected with gallium-arsenide exposure. Proper engineering controls should be installed during production of microelectronic devices where exposure to gallium-arsenide is likely. Personal protective clothing and equipment should be available to workers, and proper procedures for washing, removal of wastes, transport, and disposal of contaminated materials should be explained and carried out. Specific safety recommendations are offered for use during crystal growth, crystal puller cleaning, crystal surface grinding and sawing, and wafer polishing, backlapping, and dicing.