Is it bad for your lungs to smoke out of a bong made out of a plastic water bottle? I use a stem made out of metal and the bowl is metal but could the metal heat the plastic and melt it and does the smoke pick up carcinogens from the plastic water bottle?
As long as the bowl is over an inch away from the plastic you should be fine. After you hit it a couple times feel how hot the metal is where it touches the plastic.
Make sure you don't use aluminum foil as a bowl. Under heat, aluminum can oxidize and you can breath in aluminum oxide which is linked to alzheimers.
