Robin,
I know you've got safety in mind here and a concern for other people, and that's a good thing. If you're not sure about something you should always play it safe.
I own a fabrication shop that does commercial and industrial sheet metal work. 90 percent of our end products are galvanized. We weld galvanized steel everyday, of course with proper exhaust systems. We comply to all safety regulations. If I didn't, OSHA would be all over me in a cocaine heart beat.
There is no nationally recognized safety advisory that tells you not to weld galvanized steel.
Breathing zinc oxide fumes created by the process can cause metal fume fever...temporary flu like symptoms. There are no known long term effects.
I have done a lot of welding and have never experienced the fever because I've done it safely.
To avoid the illness, The American Welding Society recommends: "Keep your head out of the fumes and do not breathe the fumes. Use proper ventilation and exhaust. If uncertain about ventilation, use an approved respirator."
It's basically just good old common sense.
Here is the AWS full report on
Metal Fume Fever Steve
