If the iconic actor Christopher Walken was welding galvanized steel, his classic phrase from the Saturday Night Live sketch"More Cowbell" might instead be “I got a fever and the only prescription is more LEV!” LEV, or local exhaust ventilation, is a recognized industrial hygiene solution for reducing particulate pollution through dilution.
Exposure to certain fumes such as zinc oxide and magnesium oxide during the heating and welding of galvanized metal can lead to the illness known as metal fume fever. Symptoms of this condition include headache, fever, chills, muscle aches, nausea, vomiting, joint pain, and lethargy. Elevated exposure to zinc oxide fumes can also cause a sweet or metallic taste in the mouth along with a dry, irritating cough.
Metal fume fever is also known as Monday morning fever where symptom bouts typically appear most severe at the beginning of the work week. Exposed workers tend to rapidly develop some degree of adaptive tolerance, albeit transient, with repeated exposure after the weekend or vacation eliciting the telltale symptoms. Where most of the symptoms are similar to influenza and other common illnesses, the key to diagnosis is a thorough occupational history.
The American Welding Society (AWS) safety and health fact sheet no. 25 on metal fume fever lists the following tips on how to avoid the hazard.
- Keep your head out of the fumes.
- Do not breathe fumes.
- Use enough ventilation, exhaust at the arc, or both, to keep fumes and gases from your breathing zone and the general area.
- If adequacy of the ventilation or exhaust is uncertain, have your exposure measured and compared to the Threshold Limit Values (TLV) in the Safety Data Sheet (SDS) for the galvanized material.
- Never take chances with welding fumes. If none of this is adequate or practical, wear an approved respirator, air-supplied or otherwise, that adequately removes the fumes from your breathing zone.
The AWS fact sheet describes the current OSHA permissible exposure limit for zinc oxide fume at 5 milligrams per cubic meter of air averaged over an 8 hour work shift. OSHA also has a fact sheet on controlling hazardous fumes and gases during welding that cites OSHA standards applicable to welding.
So for the welder who’s sick and tired of being tired and sick - more LEV! Check out some of our previous industrial hygiene related posts for information on hexavalent chromium, combustible dust, crystalline silica, and respiratory protection.