I did some welding on our garage door today, so it dosent fall anytime soon. I did most of this welding in the garage with the door open and a fan on me. The rest i did outside where it was all breezy. Im pretty sure the garage door is galvanized steel and i also know it puts off a poisonous zinc oxide gas. I did my best holding my breath, but my question is, how bad is this stuff to breathe in?