Welding galvanized steel without proper ventilation causes metal fume fever

Zinc coating on galvanized steel vaporizes at welding temperatures, producing zinc oxide fumes that cause flu-like symptoms 4-12 hours after exposure. Per OSHA and AWS guidelines, welding galvanized material requires either grinding the zinc coating back 2-3 inches from the weld zone or welding with forced ventilation and a P100 respirator. A standard dust mask is NOT sufficient.