Diisocyanates are a family of chemical building blocks used to make a wide range of polyurethane products used every day in buildings, furniture, automobiles and other applications. The most widely used aromatic diisocyanates are toluene diisocyanate (TDI) and methylene diphenyl diisocyanate (MDI):
TDI is mainly used to make flexible polyurethane foam found in furniture, bedding, carpet underlay, packaging, coatings, sealants, adhesives and elastomers. TDI helps produce lighter automobile seating and headliners, saving weight and making vehicles more energy efficient.
MDI is used primarily to make rigid polyurethane foams used in insulation for your home or refrigerator, as well as for vehicle parts like dashboards, steering wheels and bumpers. Insulation made with MDI helps to conserve energy.
EPA notes “polyurethane products, such as mattresses, pillows, and bowling balls, are considered completely cured products before they are sold.” Fully cured products – meaning the component chemicals are completely reacted and no longer present individually – do not expose consumers to diisocyanates. EPA also states that because fully cured products are completely reacted they “therefore are considered to be inert and non-toxic.”