Features
   Polyurethane foam insulation burns quickly if ignited, emitting smoke, heat and toxic gases, according to the Occupational Health & Safety Administration. Toxic gases emitted by burning polyurethane foam include carbon monoxide, nitrogen oxides, hydrogen cyanide, benzene, acetaldehyde and acetone.

Warning
   Some types of polyurethane foam insulation claim to be "flame-resistant" or "fire-retardant." However, these products still cause large amounts of toxic gases when exposed to fire or flame, which are as lethal as a fire.

Recommendation
   Polyurethane foam insulation can be used safely if you install it in a flame-retardant and heat-retardant structure, such as gypsum board, according to the U.S. Consumer Product Safety Commission. Never allow welding, cigarette smoking or other types of flame around polyurethane foam insulation.