Spraying with paints containing isocyanate

Background

WorkSafe has found multiple workplaces spray painting with paints containing isocyanates where employers have not provided adequate risk controls to protect the health of employees.

Isocyanates are hazardous substances. They are commonly found in the hardener component of two-pack paints used in the automotive industry. Exposure to isocyanates when performing activities like spraying isocyanate-containing paint can lead to adverse health outcomes.

Safety issues

Exposure to isocyanates can cause respiratory and skin irritation and sensitisation. Breathing in spray mist containing isocyanates can cause asthma-like symptoms, including:

• Irritation of nose, mouth, throat and lungs
• chest tightness
• breathlessness or difficulty breathing
• wheezing or coughing.

The main risk associated with isocyanates is respiratory sensitisation. Once a person becomes sensitised, any future exposure to even small amounts can trigger these asthma-like symptoms. This can be life threatening if exposure continues.

Sensitisation can impact a person’s ability to continue working in the industry, as even exposure to other non-isocyanate-containing paints or solvents can trigger this asthma-like response.

People with a history of asthma and eczema should seek medical advice before working with isocyanates.

Skin contact with isocyanates can also cause skin sensitisation conditions. It can lead to chronic skin conditions like dermatitis and eczema.

Recommended ways to control risks

The following controls can help to eliminate or reduce the risks:

• Work with non-isocyanate-containing paints.
• Use spray techniques that minimise overspray.

• Use a fully enclosed spray booth. Ensure the spray booth:

  • vents safely outside
  • maintains a minimum air velocity rate of 0.25/s for down draught and 0.5m/s for side-draught
  • is run for 5 minutes after spraying to allow spray mist to clear
  • is regularly checked, tested and maintained according to the manufacturer’s recommendations. This includes replacing filters, and
  • is big enough for the objects being sprayed.

  If an object is too big for the spray booth, ensure:

  • there is a designated spray area away from other workers, isolated with barriers and signs, and
  • others are not around when undertaking spraying, or
  • if spraying is likely to occur near an area where others are working, engage an Occupational Hygienist to conduct air monitoring in a number of locations around the workplace to demonstrate that exposure levels are likely to be below detection.
• Use a full-face airline respirator meeting AS/NZS 1716 when spraying isocyanates. When using the respirator ensure:
  • the compressor air-intake is away from sources of contamination, such as motor vehicle exhaust fumes
  • consumable filters are replaced according to the manufacturer’s recommendations. This includes filters such as particulate, coalescing and charcoal filters
  • it is fitted with a double action coupling to prevent accidental disconnection
  • it is only disconnected and removed once outside of the booth
  • the compressor and filter-system are regularly serviced, and records are kept for any maintenance.
• Wear protective clothing and gloves to prevent contact with skin.

Additional controls include:

• using local exhaust ventilation (LEV) when colour matching and mixing
• cleaning spray guns using an automated gun wash system or under LEV.

Legal duties – Health monitoring

An employer must ensure that health monitoring is carried out for an employee if the employee is exposed to a hazardous substance listed in Schedule 9 of the Occupational Health and Safety Regulations (2017) and exposure is likely to cause adverse health effects. Isocyanates are a hazardous substance for which health monitoring is required.

Health monitoring must be carried out under the supervision of a registered medical practitioner.

Health monitoring procedures may include:

• medical tests, such as lung function tests
• medical examinations
• review of past and present medical and work histories
• review of medical records and workplace exposure.

Hazardous substance health monitoring report form

You must ensure a report of the health monitoring is prepared by the registered medical practitioner.

You must provide a copy of the completed form to the employee, as well as keeping a copy as a record. You must submit the health monitoring report to WorkSafe Victoria if the registered medical practitioner’s opinion is that the employee must not be exposed to the hazardous substance for a specified period of time.

You should use the Hazardous substance health monitoring report form.

Section 2 of the form should be completed by the employer for each employee exposed to any hazardous substance. Sections 3 and 4 are to be completed by the registered medical practitioner after the medical examination.

If the registered medical practitioner is not familiar with the health monitoring requirements for isocyanates, it is recommended they are referred to the Safe Work Australia guide Health monitoring for isocyanates for further information.

Other legal duties

• Employers have duties under the Occupational Health and Safety Act 2004 (OHS Act). They must, so far as is reasonably practicable, provide and maintain a working environment that is safe and without risks to the health of employees and independent contractors. This includes providing employees with the necessary information, instruction, training, or supervision to enable them to do their work in a way that is safe and without risks to health.
• Employers must also ensure that persons other than employees are not exposed to risks to their health or safety arising from the employer's conduct, so far as is reasonably practicable.
• Employers must consult with employees and health and safety representatives when identifying or assessing hazards or risks and making decisions about risk control measures.

Other relevant Health and Safety Regulations

• Employers may have additional duties under Part 4.1 Hazardous substances of the OHS Regulations.
• Employers may have a duty to conduct atmospheric monitoring where there is uncertainty that the airborne concentration of the hazardous substance exceeds the workplace exposures standard or may be at a level that is a risk to health. See WorkSafe’s guidance Exposure standards and atmospheric monitoring for more information.