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Weatherizing, insulating and sealing are important parts of energy efficiency and conservation programs creating a market for green jobs. Various types of weatherizing, insulating and sealing products include blow-in and spray-on applications. These may require a certain amount of training in order to apply these materials to product specifications in order to achieve proper weatherization. The materials used in these types of applications can include, but are not limited to: for blow-in, fiberglass and cellulose; for spray-on, spray polyurethane foam (SPF), spray polystyrene, and spray latex sealant.

Jobs in the weatherization industry (either for new homes and commercial/public buildings or retrofitting old homes and commercial/public buildings) have increased significantly over the past 10 years. Weatherization jobs include work-related activities from direct installation of weatherization and insulation materials (applicators) to assisting applicators with installation of weatherization materials to cleanup.

All weatherization applications and materials have some benefits. All weatherization applications and materials have some hazards. The hazard information and solutions common to all these applications and materials include: confined spaces, falls, electrical, medical and first aid, ventilation, proper personal protective equipment and respiratory protection. Unique hazards are outlined in the sections below under the individual materials.

Hazards and Solutions

Workers in the Weather Insulating/Sealing industry are exposed to typical workplace hazards, including the following.
In weatherization/insulation, workers can be exposed to the hazards that have been identified below:


Fiberglass has been used for many years in batting as a solid fill insulator. The main concerns for this type of application include skin and eye irritation. In addition, if the fibers are freed from the batting they can cause respiratory irritation and inflammation. For blow-in application, employers must provide workers with the proper respiratory protection. Inhalation of fiberglass material has been linked to cancer by OSHA, IARC (International Agency for Research on Cancer), and NTP (National Toxicology Program).


Cellulose is the oldest known building insulating material. Dry cellulose can be used in retrofitting old buildings by blowing the cellulose into the wall cavity using boar holes drilled at the top of the walls. Either dry cellulose or wet cellulose applications can be used in new building construction. Cellulose is a respiratory irritant (NTP, 2006). Employers should provide workers with the appropriate dust respirators when using this type of insulation material (NTP, 2006; 29 CFR 1910.1000 Subpart Z; 29 CFR 1926.55 Appendix A).

Unless treated with fire-retardants cellulose can be flammable, and should not be used around open flames (Philpot, 1970).

Spray Polyurethane Foam

Spray Polyurethane Foam (SPF) has been used as an insulating material in new construction for many years. However, a new emphasis for retrofitting older buildings to conserve energy has increased the use of SPF at least 60% in the past 5 years. Employers need to ensure that SPF application is carried out in a safe manner to protect workers. SPF contains Isocyanates, which have been reported to be the leading attributable chemical cause of work-related asthma (WRA) (NIOSH, 2004).

OSHA has identified these unique hazards associated with SPF:

Polystyrene is used as a spray-on application similar to SPF installations. Styrene may be generated during the installation process. Styrene has been shown to cause several health effects when inhaled. These include respiratory irritation, and neurological effects. Employers need to provide adequate respiratory protection and protective equipment similar to SPF installation when using this spray-on application (29 CFR 1910.1000 Subpart Z; 29 CFR 1926.55 Appendix A – Air contaminants; EPA IRIS).

Styrene is also flammable and the same controls as outlined for SPF should be used (29 CFR 1910.106 – Flammable and combustible liquids).

OSHA has identified these unique hazards associated with Polystyrene/styrene:
Latex Sealant

Latex sealant is generally used with fiberglass batting in order to provide a better seal. Because latex is a known sensitizer it can cause allergic skin and respiratory reactions in some individuals. Employers need to provide workers with proper protective equipment and respiratory protection when using this type of product to avoid unnecessary skin, eye, and respiratory exposure.

Fatalities and Incidents

OSHA has identified several fatalities and incidents due to severe asthmatic attacks and fire/explosions associated with the use of isocyanate-containing materials.

A 41-year old Springfield, Massachusetts worker was killed when the spray foam chemicals he was spraying in a home attic caught fire. A worker for a Vermont insulation company ran a hose from two 50-gallon drums of chemicals outside the house into the attic where he was applying the insulator. It is believed that the vapors of the spray chemicals then ignited and engulfed the attic. After smelling smoke, two coworkers rushed upstairs to remove the worker, but couldn’t because the flames and smoke were too intense. Firefighters were unable to reach the man by placing a ladder on the porch roof. After breaking into the side window to the attic, firefighters pulled the man’s unconscious body out of the house and performed CPR. The efforts were unsuccessful. The worker was pronounced dead at Springfield hospital that night (Cape Cod Times, May 2008).

A maintenance worker repairing a foaming system at a polyurethane foam manufacturing plant developed respiratory symptoms associated with isocyanate exposure. Detectable MDI concentrations were discovered in the workplace. There was no effective ventilation and dermal protection while investigations revealed aerosols and vapors near the faces of the workers. The worker quit his job after being diagnosed with isocyanate-induced hypersensitivity pneumonitis. Years after leaving the plant, he continued to experience symptoms including cough, weakness, sweats, muscle aches, shortness of breath and loss of lung function. The illness worsened over time, and eventually led to his death (NIOSH 1996).

A 45-year-old worker had a fatal asthma attack after spraying an MDI-based bed liner onto a vehicle interior. The worker was wearing a half mask, supplied-air respirator, latex gloves and coveralls. The room had two curtains pulled together to contain the spray, a fan at the door to provide air circulation and no local exhaust ventilation. After disconnecting the respirator and leaving the room, the worker began developing acute respiratory symptoms. He was taken to the hospital where he then went into cardiac arrest. The county medical examiner stated that the worker had died of an “acute asthmatic reaction due to inhalation of chemicals.” The health and work history of the patient suggests that MDI sensitization played a significant part in the fatality (NIOSH, 2006).

Public school officials at a large metropolitan school district became suspicious after several staff members developed asthma symptoms. NIOSH investigators were called in to inspect the school and discovered several recent isocyanate foam and coating material applications. The staff reported odors from the materials when they were being applied. Air sampling tests indicated release of isocyanates and potential for exposure (NIOSH, 2006).


Additional safety and health information is available on OSHA's web site and from the links listed below:

Environmental Protection Agency. Integrated Risk Information System.

Gouveia A. “Green” Insulation Suspected in Fatal Fire. Cape Cod Times, May 20, 2008.

National Institute for Occupational Safety and Health: Preventing Asthma and Death from MDI Exposure during Spray-on Truck Bed Liner and Related Applications.

National Institute for Occupational Safety and Health (2004): Attributable Causes for Work Related Asthma (WRA). NIOSH Publication No. 2004-146.

NIOSH Alert 1996. Preventing Asthma and Death from Diisocyanate Exposures.

National Toxicology Program. Morgan DL. (2006) NTP Toxicity Study Report on the atmospheric characterization, particle size, chemical composition, and workplace exposure assessment of cellulose insulation (CELLULOSEINS). Tox Rep Ser. Aug; (74): 1-62, A1-C2.

Philpot, C. W. 1970. Influence of mineral content on the pyrolysis of plant materials. For Sci. 16: 461-471.

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