I belong to one of the casting forums ( we cast aluminum and steel ) and about 2 years ago we lost one of members who inhaled some zinc oxide when he was melting down a bunch of scrap , he was doing this outside , he died 3 days later of pulminary problems (basically drowned in his own fluids ) which is a rather painful way to go , he always was one of the guys who cautioned us when it came to this but he got lax and it cost him his life . just remeber the organs damaged easiest are ussually the hardest ones to replace .