This monograph evaluates the evidence of carcinogenicity of metallic
cobalt particles with or without tungsten carbide, to which workers in
the hard-metal industry are exposed, and of cobalt sulfate and other
soluble cobalt (II) salts. It also evaluates three other particulate
compounds: gallium arsenide and indium phosphide, which are used
extensively in the microelectronics industry; and vanadium pentoxide, a
contaminant at facilities refining and processing vanadium-rich ores,
and in various workplaces that use oil-fired boilers and furnaces.