What kinds of toxins are released when burning roofing shingles?
In Ontario, it’s against the law to burn construction waste, including shingles, without a permit from the Ministry of the Environment (MOE). Such a permit would not be issued to a private individual for open burning but to a corporation with an approved incineration facility.
Shingles, which are mostly asphalt (a petroleum byproduct) embedded with grit, are particularly nasty to burn. They release a complex brew of contaminants, including carcinogenic polyaromatic hydrocarbons, into the air, and possibly the soil and water.
Should you ever witness people burning shingles, report them to your municipality right away. The right way to dispose of shingles is to bring them to a MOE-approved landfill site.