Metal fume fever is illness caused primarily by exposure to certain metal fumes. Chemicals such as zinc oxide (ZnO) or magnesium oxide (MgO), often cause this through breathing fumes created by heating or welding certain metals, such as galvanized steel. Chromium is also a hazard, from stainless steel. Cadmium, present in some older silver solder alloys can, in extreme cases, cause loss of consciousness within a matter of minutes. Iron itself, and so most simple steels, does not give rise to it. Neither does aluminium.
Exposure usually arises through hot metalworking processes, such as smelting and casting of zinc alloys, or welding of galvanized metals. If the metal concerned is particularly high-risk, then cold sanding processes may also cause it, even though the dose is lower. This may also occur with electroplated surfaces or metal-rich anti-corrosion paint, such as cadmium passivated steel or zinc chromate primer on aluminium aircraft parts.
The most plausible mechanism accounting for the symptoms involves an immune reaction which occurs when inhaled metal oxide fumes injure the cells lining the airways. This is thought to modify proteins in the lung. The modified proteins are then absorbed into the bloodstream, where they act as allergens.
Diagnosis of metal fume fever can be difficult, as the complaints are non-specific and resemble a number of other common illnesses. When respiratory symptoms are prominent, metal fume fever may be confused with acute bronchitis. The diagnosis is based primarily upon a history of exposure to metal oxide fumes.
An interesting feature of metal fume fever involves rapid adaptation to the development of the syndrome following repeated metal oxide exposure. Workers with a history of recurrent metal fume fever often develop a tolerance to the fumes. This tolerance, however, is transient, and only persists through the work week. After a weekend hiatus, the tolerance has usually disappeared. This phenomenon of tolerance is what led to the name "Monday Fever".
Particularly for cadmium, the design of the product may be changed so as to eliminate it. NiCd rechargeable batteries are being replaced by NiMH. Cadmium plating is replaced with zinc or nickel. Silver solder alloys now rarely contain it.