Tungsten and compounds in the absence of Cobalt
Tungsten metal; Wolfram; Tungsten compounds; [NIOSH] Tungsten and compounds;
Hard, brittle, steel-gray to tin-white solid; [NIOSH]
Tungsten is used in ferrous and nonferrous alloys to make filaments in incandescent lights, welding electrodes, heating elements, and rocket nozzles. Tungsten carbide (cobalt) is used in abrasives and high-speed tools. Exposures to tungsten dusts occur in milling and refining wolframite and sheelite ores; Also used as petroleum refinery catalysts and in nanomaterials (pigments, lubricant additives, electronics, and lighting); [ACGIH]
The TLV is recommended "to protect against lung damage." "Oral doses of soluble sodium tungsten tungstate dihydrate given to mice and rats were almost completely eliminated within 24 hours. Humans received large oral doses (200 mg/day) of soluble sodium tungstate over a 6-week period without adverse effects (compared to placebo controls)." [ACGIH] Tungsten resembles molybdenum; Excess absorption of tungsten may antagonize the action of molybdenum, an essential trace nutrient; Hard metal disease is believed to be caused by cobalt, which is fused with tungsten carbide in hard metal tools; Systemic effects from tungsten have not been reported after occupational exposure; [Nordberg, p. 1297-1305] A skin, eye, and respiratory tract irritant; [CAMEO] See "Tungsten carbide (cemented)."
Skin Designation (ACGIH)
3 mg/m3, as W, respirable particulate matter
Industrial Processes with risk of exposure: