Spray-on polyurethane products containing isocyanates have been developed for a wide range of retail, commercial, and industrial uses to protect cement, wood, fiberglass, steel and aluminum, including protective coatings for truck beds, trailers, boats, foundations, and decks.

Polyurethanes are formed by combining a variety of chemicals. The most important ingredient is the family of isocyanates.

Isocyanates are a group of chemicals used in the manufacture of polyurethane plastics, synthetic rubbers, foams, paints, varnishes and adhesives.

polyurethanes and isocyanates

The family of isocyanates includes:

Toluene Diisocyanate (TDI), Methylene Bisphenyl Diisocyanate (MDI), also known as Diphenyl Methane Diisocyanate, Hexamethylene Diisocyanate (HDI), Naphthalene Diisocyanate (NDI), and Diisocyanate Dicyclohexyl Urethane.

Risks from use of polyurethanes and isocyanates

All isocyanates are hazardous substances and require care in handling. Many workers exposed to polyurethanes and isocyanates require health surveillance.

Isocyanates are powerful irritants to the mucous membranes of the eyes, gastrointestinal and respiratory tracts.

The greatest risks come from physical contact with, or inhaling, vapours or dust containing isocyanates. Direct skin contact can cause marked skin inflammation and rashes, and inhalation can sensitize workers, making them subject to severe asthma attacks causing reduced lung function with death a potential outcome.

For more, see the WorkSafe Isocyanate Health Surveillance Guide for employers in WA.

Find out more about our onsite health surveillance services in Perth and around WA.

OSH regulations for isocyanates

polyurethanes and isocyanates

The Occupational Safety and Health Act 1984, requires employers or PCBU’s to provide and maintain a work environment in which employees are not exposed to hazards.  This includes training, information, supervision and personal protective clothing and equipment.

Under the Occupational Safety and Health Regulations 1996, regulation 5.1 defines ‘health surveillance’ and regulation 5.23 requires an employer, main contractor or self employed person to provide health surveillance to a worker in relation to hazardous substances – this includes isocyanates.

See more in the WorkSafe WA Isocyanate Health Surveillance Guide for employers and the DMP Minerals Industry Safety handbook for mine workers.

Health Surveillance for polyurethanes and isocyanates

Due to the health issues associated with isocyanate exposure in WA, there is legislation, governed by WorkSafe, requiring employers exposing employees to these chemicals in the workplace, to have a Health Surveillance (monitoring) program.

This includes a health questionnaire, skin and eye check and a lung function test. It can usually be done in 20-30 minutes, and is required every 6-12 months pending health assessment outcomes.  More frequently for employees new to the role. Early recognition of employee sensitisation to isocyanates is essential to reduce the risk of long-term or permanent respiratory problems.

Preventing exposure to isocyanates is the critical step in reducing the health hazard. Engineering controls such as closed systems and ventilation should be the principal method for minimizing exposure. Other controls, such as worker isolation, personal protective clothing and equipment are also necessary.

Find out more about our onsite health surveillance services in Perth and around WA.

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Exposure to isocyanates in WA

As a general guide, processes that involve spraying polyurethanes and isocyanates pose the greatest workplace risk.

3 types of workplaces stand out as having the highest risk of isocyanate exposure in Western Australia.

  1. workplaces where isocyanates are mixed with a resin and then sprayed to produce an insulating foam – droplets containing isocyanates are the main hazard because they can be inhaled and absorbed by the body; powder coating
  2. workplaces where TDI is mixed with resins in the manufacture of foam – isocyanate vapours released during mixing and curing are the main hazard
  3. workplaces where two-part polyurethane paints are sprayed, most typically in the painting of motor vehicles.

Contact us to find out if you are required to do health surveillance for your employees