The U.S. Environmental Protection Agency (EPA) has released action plans to address the potential health risks of methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), and related compounds. Americans may be exposed to these chemicals when they are used in certain applications such as spray foam insulation, sealing concrete or finishing floors. The plans identify a range of actions the agency is considering under the authority of the Toxic Substances Control Act. Spray polyurethane foam (SPF) is a highly-effective and widely used insulation and air sealant material. However, exposures to its key ingredient, isocyanates such as MDI, and other SPF chemicals in vapors, aerosols, and dust during and after installation can cause adverse health effects.