Under Work Health and Safety Legislation in Australia, a duty holder is required to work through the hierarchy of control measures when managing the risks associated with hazardous noise in the workplace.
A workplace must always aim to eliminate the risks arising from hazardous noise, and if it’s not reasonably practicable, it must minimise the risks so far as is reasonably practicable.
The most effective control measure in the hierarchical structure for noise control is to eliminate the source of noise completely. This can be done by ceasing to use a noisy machine, or by changing work practices so hazardous noise is not produced.
Minimising the risks associated with hazardous noise in the workplace can be affected by such methods including, substituting plant or process to reduce noise (i.e., buy ‘quiet’ policy, changing the way the job task is done, or replacing ototoxic substances with other less harmful products), and isolating or separating the hazard or hazardous job task from any person exposed to it (i.e., locating noise sources further away from workers or using remote controls to operate noisy plant from a distance).
Engineering controls are physical control measures to minimize risk, and involve modifying equipment, process, or the environment in some way so that less sound energy is created or is transmitted to the workers.
Administrative controls are designed to lower the noise exposure by limiting the time workers spend in high noise areas. These measures are often necessary when engineering controls are not feasible or cost effective.
If all practicable noise control measures have been exhausted, and the noise remains above the WES, suitable Hearing Protection Devices (HPDs) must be issued.
Further information and guidance on controlling the risk of hazardous noise can be found in: The Safe Work Australia (SWA), Code of Practice (COP): Managing hazardous noise and preventing hearing loss at work’ (2018), and AS/NZS 1269.2 Occupational noise management – Noise control management.
A duty holder that controls noise through various methods may benefit in numerous ways:
Although you may choose to consult with a noise control engineer to assess your situation and design solutions, it is extremely beneficial to involve the workers who work in noisy areas as part of a team working to find ways to lower the noise. A consultant can bring tremendous technical knowledge but the people who spend each day immersed in the noise can provide some of the most practical and straightforward solutions because they know the processes and equipment so well.
It might seem obvious, but the process of controlling hazardous noise in the workplace cannot really begin until the workplace has completed a noise hazard assessment and analyzed the results. By monitoring noise in different areas of the facility and by conducting Noise Assessments on different processes, tasks and tools, a duty holder will collect the data necessary to identify groups of workers and areas where noise controls are most needed and prioritize where and how to spend noise control dollars to get the greatest benefit. Then, a more detailed noise control survey can be done to identify the noise sources and select the most appropriate noise control solution.
Making equipment and processes less noisy during design and fabrication is more effective and economically efficient than implementing noise controls afterward. Buy Quiet is a type of Prevention through Design approach which places a priority on eliminating or controlling the hazard by specifying machinery or tools that create less noise. This is accomplished when a new production processes is being designed or when older equipment or processes are replaced.
Prioritising the potential noise control projects is an important step towards achieving the most economic outcome. While it may seem logical to focus attention on the highest noise source in your facility, it is possible that you can achieve a more significant decrease in employee noise exposures by first controlling noise in the areas closest to where a large percentage of your workers are working. Some noise controls are fairly inexpensive and, when successful, can gain tremendous support from workers and management.
If eliminating the noise hazards and associated risk isn’t reasonably practicable, the next step is to minimize the risk by applying one or more of the following controls:
According to AS/NZS1269.2, when setting treatment priorities, the key issues are the feasibility of various noise control measures and their respective costs and benefits. Demonstrating that a certain noise control solution is technically feasible may be fairly straight forward but documenting the economic feasibility can be a challenge.
Some questions to consider are:
Weighing up all significant factors, selecting the best treatment options and determining treatment priorities based on the relative severity of each noise problem will provide you with a foundational and prioritized treatment list for your noise control plan.
Perform noise measurements once controls are in place and periodically afterwards to verify and document the results. Establish a schedule to monitor the effectiveness of noise control materials and mechanisms as they age and, potentially, deteriorate over time due to wear and tear. Whenever changes are made to processes and production, review what the effects may be in terms of existing noise controls.
Work Health and Safety Legislation in Australia limit a worker's noise exposure to LAeq,8h of 85 dB(A), referenced to 20 µ Pa (averaged over an 8-hour exposure) or C-Weighed peak sound pressure level of peak exposure of 140 dB(C) referenced to 20 Pa. A PCBU must limit the 8-hour noise exposure of workers to 85 dBA or below using noise controls and also have the option to use HPD's when other control are impractical or excessively costly.
If noise controls fail to reduce sound levels to the required Workplace Exposure Limit (WES) or below, a duty holder must provide and select hearing protection devices (HPDs) that minimize risks to worker health and safety by ensuring that it is:
Individual fit of personal hearing protectors is critical for optimum protection. 3M strongly recommends fit testing of hearing protectors as an indicator of the noise reduction obtained by individual worker. OSHA, NIOSH and the National Hearing Conservation Association (NHCA) have endorsed hearing protector fit testing as a best practice.
In the most basic sense, limiting the noise exposure of workers can be accomplished by applying controls to the noise Source, the noise Path or the Receiver.
Source modification addressed the root cause of a noise problem. The noise source is a vibrating object—a machine or tool creating vibration during operation that radiates into the work area as noise. Source noise can be treated via modification, retrofit, substitution and relocation.
Control of the sound transmission path only addresses the symptoms of noise. Noise travels through the air, of course, but also through solid materials such as floors, walls and windows. Path noise control treatment includes partial barriers, surface treatments and enclosures.
Receiver treatment is the most practical for job tasks that are conducted in one location and confined in a relatively small area. In hearing conservation, the receiver is the worker. Receiver noise control treatment aims to reduce the workers noise exposure via acoustically treating the space or worker area.
Engineering controls involve modifying the equipment, process, or environment in some way so that less sound energy is created or is transmitted to the workers. Often, the most effective approach is to identify and treat the source of the noise, based on the results of a noise control survey.
Administrative controls are designed to lower the noise exposure by limiting the time workers spend in high noise areas. These policies are often necessary when engineering controls are not feasible or cost effective.
For example, a workplace can adopt a Buy Quiet approach, specifying less noisy equipment and processes during the design phase. However, when eliminating the noise is not feasible, there are approaches to lowering the risk of noise-induced hearing loss, either through engineering a solution or applying an administrative policy to limit noise exposure.
Noise control images used courtesy of Associates in Acoustics, Inc.
The benefits of effective noise control (described above) can be expanded by implementing a Buy Quiet policy.
Why Buy Quiet?
One of the most cost-effective ways of reducing noise in a workplace is to 'buy quiet'. Purchasing quiet products can reduce noise levels without additional modification to equipment or the workplace. Specifying less noisy tools and processes during the design phase may help duty holders avoid costly noise controls once long-term purchases and commitments have been made.
Benefits of Buy Quiet
Noise, SafeWork Australia
See “Codes and Guides” tab links to: Model Code of Practice: MANAGING NOISE AND PREVENTING HEARING LOSS AT WORK: October 2018.
This page also includes links to State and Territory Regulators for specific local requirements
The Australian Standard AS/NZS 1269 series, Occupational noise management (1 – 4), provides technical requirements and guidance on all facets of occupational noise management.
IMPORTANT NOTE: This information is based on selected current national requirements. Other country or local requirements may be different. Always consult User Instructions and follow local laws and regulations. This website contains an overview of general information and should not be relied upon to make specific decisions. Reading this information does not certify proficiency in safety and health. Information is current as of the date of publication, and requirements can change in the future. This information should not be relied upon in isolation, as the content is often accompanied by additional and/or clarifying information. All applicable laws and regulations must be followed.