Spraying produces isocyanate vapors and aerosols. Inhalation exposures during SPF insulation are likely to exceed Occupational Safety and Health Administration (OSHA) occupational exposure limits (OELs) and necessitate skin, eye, and respiratory protection, according to research. Isocyanates are known carcinogens that can cause asthma attacks when they reach sensitive areas of the body. People who work with isocyanates should use caution not to contaminate their clothes with residue from wear. They should wash items that have been in contact with isocyanates thoroughly before wearing them again. Isocyanates are also flammable gases that may produce an ignitable mixture with air when heated to temperatures above 120 degrees Fahrenheit. This condition is called "flash point." The higher the flash point, the less risk there is of a fire occurring if the insulation is disturbed or comes into contact with heat or flame. The flash point of commercial polyisocyanates ranges from 180 to 280 degrees F., depending on the specific chemical used. The flash point of pure TDI, for example, is 250 degrees F. ; that of pure MDI, 260 degrees F. People who work with isocyanates should take special precautions to avoid exposing themselves to this hazard. They should use protection such as protective clothing, gloves, and safety shoes when working around these chemicals.