In-depth survey report: spray polyurethane foam chemical exposures during spray application, All About Kids, Crestwood, KY.
Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, EPHB 005-163, 2014 Dec; :1-25
The American Resource and Recovery Act of 2009 promoted green jobs and energy efficiency. Spray polyurethane foam (SPF) installation is a green job. SPF is a highly-effective and widely used insulation and air sealant material. However, exposures to its key ingredient, isocyanate, and other SPF chemicals in vapors, aerosols, and dust during and after installation can cause asthma, sensitization, lung damage, occupational asthma, and skin and eye irritation. Past studies have shown sprayers' exposures to methylene diphenyl diisocyanate (MDI) to range from 7.0 to 205 u/m3, (OSHA PEL=200 u/m3 as a fifteen minute ceiling limit) indicating the need to better understand exposure during SPF installation. Studies characterizing both MDI exposure as well as exposures to the other chemicals present in SPF are limited. This survey was conducted to determine the extent of exposure to the 4,4'-methylene diphenyl diisocyanate (MDI) monomer, isocyanate functional group (NCO) monomer, NCO oligomer, total NCO, pentamethyl-dipropylene-triamine, tris-(1-chloroisopropyl-2) phosphate (TCPP), triethylphosphate, ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol, tetraethylene glycol, and 1,1,1,3,3-pentafluoropropane, all found in SPF. Air sampling was conducted to characterize the chemical exposures to compounds present during SPF installation during three work shifts. Personal breathing zone air samples were collected for MDI, NCO monomer, and NCO oligomer. The mean MDI concentration for the sprayer was 10.1 u/m3 ranging from 4.85 to 18.7 u/m3. The helpers' mean MDI concentration was 2.86 u/m3, ranging from 0.18 to 7.89 u/m3. None of these measurements exceeded the NIOSH TWA REL of 50 u/m3. Area air samples were collected for: MDI; NCO monomer; NCO oligomer; total NCO; an amine catalyst (pentamethyldipropylene triamine); two flame retardants (TCPP and triethyl phosphate); glycols (ethylene glycol, diethylene glycol, propylene glycol, triethylene glycol and tetraethylene glycol); and blowing agent (1,1,1,3,3-pentafluoropropane). These air sample results showed the presence of all of the chemical compounds sampled for except the glycols. Based on concentrations found in the personal breathing zone air sample results the sprayer should use supplied-air full-face respirators and wear coveralls, head and foot covers, and chemical resistant gloves. The helper should use air-purifying full-face respirators and wear coveralls, head and foot covers, and chemical resistant gloves. The results from the samples collected from the perimeter area indicated that all workers should wear personal protective equipment (PPE) (i.e. full-face respirator, coveralls, head and foot covers, and gloves) at all times while in the work area and those workers without the proper PPE should remain outside of the work area. Based on these sampling results, an engineering control research study should be conducted to reduce exposures to the chemicals found in SPF when it is being installed. The sampling results indicate that MDI as well as chemical compounds found in the B-component side are present and need to be removed from the spraying area.