Copper is not considered as hazardous as metals such as mercury, lead, and manganese, but it does have ill-effects. According to NIOSH, as a dust, it may cause irritation of the eyes, nose, and pharynx, nasal septum perforation , metallic taste, and dermatitis. Also, according to NIOSH, as a fume it can cause irritation of the eyes, upper respiratory system, metal fume fever, chills, muscle ache, nausea, fever, dry throat, cough, weakness and exhaustion, metallic or sweet taste, and discoloration of the skin and hair.
Copper dust or mist may be created from mechanical or thermal atomization, electrical processes, chemical reduction, and grinding and machining. Copper fumes are produced when welding on copper, brass, and bronze and using welding rods or wires containing copper. It may also be released in smelting and refining, and foundry operations.
The OSHA Permissible Exposure Limit for copper dust and mist is 1 milligram per cubic meter (mg/m3) and 0.1 mg/m3 for fumes. The American Conference of Governmental Industrial Hygienists Threshold Limit Value is 1 mg/m3 for copper dust and mist and 0.2 mg/m3 for mist.
Copper is used in many industries due to its electrical conductivity, thermal efficiency, durability and anti-microbial properties. These include electrical and electronics industry, construction, plumbing, manufacturing and transport, and healthcare. Several types of welding processes and materials involve or contain copper. This may be as either a base metal being joined as a specialized filler, wire, or as a thin anti-rust coating on steel wires. Copper combined with zinc are used when welding on bronze. The zinc melts and boils off at a much lower temperature than copper. Both metals can cause metal fume fever.
Controls for exposure to copper dust include engineering such as local exhaust ventilation at the point of generation, use of water and mists, enclosing the operation or machinery, employee work practices such as using the wet methods, and HEPA vacuuming in place of dry sweeping or high pressure air cleaning. In addition, use of protective clothing where employees keep these only at work, kept clean or disposed, keeping eating and change areas free from dust, and personal hygiene can be effective in protecting workers.
Controls for exposure to copper fumes include local exhaust ventilation such as fume extractors or hoods at the source of welding, cutting, melting, or brazing. Process modification, and personal hygiene, protective clothing, and clean eating and change areas can also be effective when using copper. Respiratory protection may be used for both copper fumes and dust. However, as with all hazards, controls should first be implemented to bring down exposures so they are not needed.
Most exposures to metals, including copper, can have ill effects. It is important that employers as well employees, recognize the hazard and implement a program to control the hazard.
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