One of the least understood issues when managing the risk of hearing loss is the combined exposure to noise and ototoxic chemicals.

There is widespread potential for hearing loss in Vehicle Repair Workshops. Prolonged and excessive exposure to noise results in long term harm to your hearing. This is irreversible, once you lose your hearing that’s it – it’s gone!

Exposure to some chemicals can result in hearing loss. These chemicals are known as ototoxic substances. Hearing loss is more likely to occur if a worker is exposed to both noise and ototoxic substances.

Many high noise activities are regularly undertaken at Vehicle Repair workshops. Removing and repairing body panels using pneumatic tools can be noisy work: air saws and chisels can typically produce levels as high as 107 dB(A) and grinders and orbital sanders 97 dB(A). Noise levels from panel beating and other repair operations using hand tools are variable but generally high.  Welding and flame-cutting can also be noisy, and paint booths have been measured at 90 dB(A).

Work Related Chemicals

Many commonly used chemicals in Vehicle Repair workshops are ototoxic substances. For organic solvents such as toluene, styrene or xylene, the combined exposure with noise increases the risk of hearing loss in a synergistic manner.

Exposure standards for chemicals and noise have not yet been altered to take account of increased risk to hearing. The Managing Noise and Preventing Hearing Loss at Work Code of Practice 2011, recommends that the daily noise exposure of workers exposed to ototoxic substances be controlled to 80 dB(A) or below and that workers exposed to ototoxic substances undergo audiometric testing.

Control measures such as substitution, isolation and local ventilation should be implemented to eliminate or reduce exposures. Personal protective equipment should be used to prevent skin and respiratory absorption when other controls are insufficient.

In many situations exposure to ototoxic substances can be eliminated or reduced through substitution with safer alternatives. There are readily available safer alternatives to the solvents used for parts degreasing, brake cleaning, cleaning paint equipment and surface preparation. Some examples of safer alternatives can be found at the Environmental Fluids Systems website.

For information on workplace noise assessments click here.

For information on hazardous chemical risk assessments click here.

Spray Booth Air Flow Testing and Clearance Time Testing

A properly designed and operating spray booth is required to contain and remove spray painting hazardous chemicals and vapours. Spray booths are used for a variety of applications. Contaminants commonly encountered in spray booths include; organic solvents, isocyanates and polymers. Inhalation of paint vapours and overspray may result in respiratory irritation, respiratory sensitization, asthma, reduced lung function and nervous disorders.

Good maintenance and regular testing is essential to ensure that spray booths and spray rooms continue to remove contaminates in the air before people breathe them. It is a legal requirement that any PCBU who uses spray booths must ensure it is operating effectively and is checked regularly.

Air Flow Meter

The Queensland Work Health and Safety Regulations 2011 Chapter 7 requires that spray booths have ventilation systems capable of producing a minimum air movement or air flow of:

• 0.3 metres/second (m/s) for full down draught booth;
• 0.4 m/s for electrostatic spray painting booths;
• 0.5 m/s for any other booth.

The air flow must be measured when the booth is empty, during the spray cycle in the area that the spray painting is done.

The Spray Painting and Powder Coating Code of Practice October 2012 states that the plant and equipment used in spray painting or powder coating activities should be inspected at regular intervals and maintained according to manufacturer’s specifications.

The Spray Painting and Powder Coating Code of Practice October 2012 also recommends that spray booths should have a sign indicating the time workers should allow for chemicals to clear before entering the spray booth. This is commonly referred to as the clearance times. The clearance time is determined by conducting a smoke clearance test. The spray booth is filled with non-hazardous smoke and the time that the booth takes to remove contaminates is recorded as the clearance time.

Records for air flow testing and clearance times should be kept onsite.

For information on our spray booth air flow testing and clearance time services click here.

For further information on how we can assist you with noise assessment services call our office or use our contacts page to forward a request for further information.

Sunshine Coast, Brisbane, Gold Coast and Regional Queensland