How to assess and manage workplace noise

Noise is pervasive and often unavoidable in construction work. However, the potential for hazardous noise to cause hearing loss is not always obvious.

This information is intended to assist Persons Conducting a Business or Undertakings (PCBUs), employers, and other people with workplace health and safety obligations to assess, manage and control risks in relation to noise.

What is the noise exposure standard?

To comply with regulatory requirements, you must ensure that the noise that people (workers or employees) are exposed to at the workplace does not exceed the exposure standard for noise.

If people at the workplace are exposed to noise that exceeds the exposure standard, this exposure will need to be reduced to protect against the risk of hearing loss.

The exposure standard for workplace noise is 85 dB(A) averaged over an eight-hour period, and a maximum peak noise level of 140 dB(C). The term ‘dB’ is the abbreviation for decibel - the unit used to measure sound.

How long can you be exposed to noise before the exposure standard is exceeded?

Whether the noise exposure standard is exceeded depends on the level of noise involved and how long a person is exposed to it. For example, if a machine, plant, or tool produces a peak sound level of over 140 dB(C) at any time, for example an explosive powder-actuated tool, then the exposure standard will be exceeded with a single firing.

For other exposures, Attachment A shows the dB(A) noise levels and the total length of time someone can be exposed to that noise level before the standard is exceeded.

How do I determine the exposure to noise?

You can determine the exposure of a person to hazardous noise by carrying out a noise assessment.

A noise assessment may be simple or complex depending on what is causing the noise, the range of sources of noise and the nature of the work.

Simple example: If only one noisy activity is carried out and the manufacturer has provided information about the machine’s noise level when it is operated in a particular way, then a sufficient estimate of exposure can be made without measurement.

Complex example: More complex situations may require noise exposure measurement to accurately determine a person’s exposure to noise. For example, workplaces with variable noise levels over a shift, or with several noise sources, and jobs where workers move in and out of noisy areas.

The noise assessment needs to be done:

• over the working day, ensuring exposure to noise over the day is representative of the person’s long-term exposure to noise at the workplace and
• without considering the effect of any personal protective equipment (PPE) worn, such as earmuffs or earplugs.

Further information on how to do a noise exposure can be found in the code of practice for managing noise and preventing hearing loss at work (Code of Practice) and your local work, health and safety regulatory website.

How should I manage the risk of exposure to hazardous noise?

When a noise assessment determines that a person can be exposed to levels of noise that exceed the exposure standard, the source of noise to which the person is exposed must be eliminated if that is reasonably practicable.

If eliminating the source of noise is not reasonably practicable, exposure to noise must be reduced as far as reasonably practicable.

If in the case study below, the source of noise cannot be eliminated, the number of nailings could be reduced to reduce the worker’s exposure to noise. For example, having the frames prefabricated would considerably reduce the number of nailings required and the worker’s exposure to noise.

Another option would be to substitute the nail gun with a less noisy model.

If after applying similar control measures, exposure to noise cannot be reduced to below the exposure standard, PPE must be used to reduce the worker’s exposure to below the exposure standard.

However, relying on PPE to reduce exposure to noise must only be considered after all other noise exposure reduction options have been applied as far as reasonably practicable.

Hearing tests

If workers (or employees in Victoria) are required to frequently use PPE to protect the worker from the risk of hearing loss associated with noise that exceeds the exposure standard, hearing tests (audiometric testing) need to be provided for the workers.

Audiometric testing is mandatory in all Australian states and territories except Queensland where it is recommended.

Audiometric testing must be provided within three months of the worker commencing work. Regular follow-up tests must be carried out at least every two years.

Starting the audiometric testing before people are exposed to hazardous noise (such as new starters or those changing jobs) provides a baseline as a reference for future audiometric test results.

Case study: Estimating noise exposure

A worker uses a powered nail gun to build house frames and to fix prefabricated roof trusses throughout the day.

The decibel value stated on the power tool, or specified by the manufacturer, shows that the nail gun produces a noise level of 109 dB(A) each time it is fired, and for each firing the noise lasts a quarter of a second (0.25 s).

The worker estimates that 500 nails are fired over an 8-hour workday. The total time of exposure to nail gun noise is 500 multiplied by 0.25 s which equals 125 seconds (2.08 minutes).

Attachment A indicates that at a noise level of 109 dB(A) the exposure standard for noise will be exceeded in 1.9 minutes. Therefore, it can be assumed that the worker is likely to be exposed to hazardous levels of noise above the exposure standard.

The actual exposure to noise is likely to be greater than that, as other sources of noise are likely to also be present.  This needs to be considered when determining exposure in other scenarios which can be assessed using the guidance and ready reckoner in the code of practice for managing noise and preventing hearing loss at work.

Table A: Determining noise exposure

Someone being exposed to 88 dB(A) for more than four hours would exceed the standard. Similarly, if a person uses a tool that generates 121 dB(A), the exposure standard will be exceeded after only 7.5 seconds.

Most construction power tools produce noise levels ranging from 90 dB(A) and 110 dB(A), while some explosive powder-actuated nail guns can produce peak noise levels of close to or more than 140 dB(C).

To find out more, contact HIA's Contracts and Compliance team

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