Metal fume fever is from mostly the nickle and chromium in stainless or other steels like inconel or cobalt. It will leave a taste of copper or metal in your mouth. It comes from welding with poor ventilation. Welding outside will reduce the chance of getting it. Or wearing a fresh air hood will just about remove the chance all together. Galvanized metal will give you zinc poisoning (blood poisoning), you can prevent it by drinking milk before or shortly thereafter welding it.