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Health Concerns about Spray Polyurethane Foam

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Individuals with a history of skin conditions, respiratory allergies, asthma, or prior isocyanate sensitization should carefully review product information when considering the use of spray polyurethane foam (SPF) products and may want to consider safer alternatives.

Manufacturers recommend in their isocyanate safety data sheets that individuals undergo medical surveillance prior to working with these materials and individuals with a history of medical conditions as described above will be restricted from work with isocyanates.

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Health concerns associated with side A: isocyanates

Isocyanates are a class of highly reactive chemicals with widespread industrial, commercial, and retail or consumer applications.

Exposure to isocyanates may cause skin, eye and lung irritation, asthma, and “sensitization.” Isocyanates are irritants to the mucous memmbranes of the eyes and gastrointestinal and respiratory tracts. Direct skin contact can also cause marked inflamation. There is no recognized safe level of exposure to isocyanates for sensitized individuals. Isocyanates have been reported to be a leading attributable chemical cause of asthma in the workplace.

Dermal, eye, and respiratory exposures can trigger adverse health responses. EPA, other federal agencies, states, industry, and other countries have taken a variety of actions to address risks posed by exposure to isocyanates. Exposures to isocyanates should be minimized.  

Read the National Institute for Occupational Safety and Health (NIOSH) alert "Preventing Asthma and Death from MDI Exposure During Spray-on Truck Bed Liner and Related Applications."

NIOSH cited these potential health effects:

  • Isocyanates have been reported to be a leading chemical cause of work-related asthma, a potentially life-threatening disease.
  • Exposure to isocyanates can cause contact dermatitis, skin and respiratory tract irritation, sensitization, and asthma.
  • Both skin and inhalation exposures can lead to respiratory responses.
  • Isocyanates can cause “sensitization,” which means that some people may become allergic to isocyanates and could experience allergic reactions including: itching and watery eyes, skin rashes, asthma, and other breathing difficulties. Symptoms may also be delayed up to several hours after exposure.
  • If you are allergic or become sensitized, even low concentrations of isocyanates can trigger a severe asthma attack or other lung effects, or a potentially fatal reaction. There is no recognized safe level of exposure to isocyanates for sensitized individuals.


  • Sensitization may result from either a single exposure to a relatively high concentration or repeated exposures to lower concentrations over time; this is an area where additional investigation and research is needed.may
  • Even if you do not become sensitized to isocyanates, they may still irritate your skin and lungs, and many years of exposure may lead to permanent lung damage and respiratory problems.

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Health concerns associated with side B: polyol blend

Side B contains a blend of proprietary chemicals that provide unique properties in the foam, and may vary widely from manufacturer to manufacturer. 

  • Catalysts may be amine or metal catalysts
  • Amine catalysts in SPF may be sensitizers and irritants that can cause blurry vision (halo effect)
  • Flame retardants, such as halogenated compounds, may be persistent, bioaccumulative, and/or toxic chemicals (PBTs). Some examples include:
    • TCPP -(Tris(2-chloroisopropyl)phosphate)
    • TEP -(Triethyl phosphate)
    • TDCP -(Tris (1,3-dichloroisopropyl) phosphate blend)
  • Blowing agents may have adverse health effects
  • Some surfactants may be linked to endocrine disruption

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