Under these conditions, spray foam has the potential to emit hazardous pollutants. Years later, building modifications, destruction, or disassembly might affect spray foam insulation. Working hot on or near polyurethane foam might expose you to isocyanates and other harmful pollutants. The chemicals in spray foam can cause serious health problems if they are not removed promptly from the site. Spray-applied polyurethane foam is generally less toxic than other types of insulation materials because it does not release gases that may damage lungs like cellulose fibers, and it does not pose a fire hazard like mineral wool. However, it is still a chemical that should be handled carefully if it is going to be disposed of as solid waste. Chemicals used in its production are released into the environment when it is burned or discarded in landfills. They also can enter water sources through runoff from construction sites. People who work with polyurethane foam often suffer from respiratory problems due to the chemicals used in its manufacture. These include irritations of the skin, eyes, and mucous membranes, as well as cancer. Isocyanates are known human carcinogens. Other hazardous substances found in spray foam include methylene chloride, toluenes, and xylene. All of these substances are toxic if inhaled or absorbed through your skin. In addition to being hazardous to humans, spray foam is disruptive to the environment.