Spray Polyurethane Foam

Spray polyurethane foam (SPF) is an approved WAP air sealing measure.  SPF is a widely used and highly-effective insulator and air sealing material; however, eye, skin, and inhalation exposures to its key ingredient, isocyanates, and other SPF chemicals in vapors, aerosols, and dusts during SPF installation can cause:

  • Asthma, a potentially life-threatening disease
  • Respiratory problems and other breathing difficulties
  • Skin and eye irritation
  • Other potential adverse health effects

The following web sites provide important health and safety information concerning spray polyurethane foam.


Environmental Protection Agency (EPA)
EPA’s spray polyurethane foam (SPF) web site provides health, safety, and use information to help educate and ensure that best practices are used when SPF is applied.


Occupational Safety and Health Administration (OSHA)
OSHA regulates workplace exposures of methylene diphenyl diisocyanates (MDI). The enforceable permissible exposure limit for MDI is 0.2 mg/m3 as a ceiling limit (0.02 parts per million). Isocyanates: OSHA Standards page provides background to final rules and official letters of interpretation of the standards. The OSHA safety and health topics isocyanates page provides information on health effects.


National Institute for Occupational Safety and Health (NIOSH)
NIOSH issued two “Alerts” and guidance to prevent asthma and death from exposures to isocyanates:

The NIOSH recommended exposure limit (REL) for methylenebis(phenyl isocyanate) (MDI) [0.05 mg/m3 (0.005 parts per million) as an 8-10 hour time weighted average] is intended to prevent acute and chronic health effects including irritation and sensitization of workers. However, the NIOSH REL is not intended to prevent health effects in workers who are already sensitized. There is no recognized safe level of exposure for sensitized individuals, whether it is in the workplace or other settings where exposures may occur. This is of concern because of the increased use of diisocyanates in industrial as well as consumer products.


Health and Safety Information from Other Organizations
The American Chemistry Council’s Center for the Polyurethanes Industry (CPI) and the Spray Polyurethane Foam Alliance (SPFA) have developed communication and product stewardship materials targeted to SPF professionals and posted them on their spray polyurethane foam: health and safety site. In addition, a robust set of training materials for professional applicators is available on this site.


Program Notices and Memoranda