Controlling hazardous noise in the workplace
Employers, businesses and other PCBUs must effectively manage the risks associated with exposure to hazardous noise to protect workers from to the risk of hearing loss, both gradual and immediate and any associated tinnitus, and create a less stressful and more productive work environment.
Effective control starts with recognising all potential sources of risk.
Eliminate the hazard
Eliminating hazards at the design or planning stage of new and/or renovated workplaces is often easier and cheaper to achieve than making changes later when the hazards become real risks in the workplace.
It is vital to aim to build the quietest workplace practicable, so PCBUs and designers of buildings and structures must consult with each other, take noise control into account and minimise the noise transmitted through the structure to the lowest level that is reasonably practicable.
You need to use the hierarchy of controls by considering:
- installing fully automated plant and equipment to mechanically and/or remotely undertake work involving hazardous noise
- where to locate noisy plant, equipment and work processes and the effect on noise levels of building reverberation, the building layout relative to any plant. Aim to keep machines, processes and work areas of approximately equal noise levels located together
- the type of plant and equipment to be installed. Consider the type of noise they generate (e.g. continuous; impact; intermittent; etc) and the noise level. Avoid impact noise as far as is reasonably practicable. So far as is reasonably practicable, purchase items with the lowest noise exposure levels
- designing acoustic treatments for noisy areas, e.g. cover ceilings and walls with sound-absorbing material, use floating floors
- using flexible construction joints as building elements
- designing walls, floors, windows and doors to provide the necessary sound transmission loss
Isolate the hazard
Isolation controls can include:
- installing a control room to isolate workers
- installing sound isolation booths
- installing remote controlled equipment
- using enclosed cabins on mobile equipment
- separating quiet and noisy areas. Low noise tasks like office work, packaging, cleaning, maintenance and repair work should be carried out in separate low-noise areas
- installing buffer zones, sound-proof barriers and/or enclosures
Engineering controls can include:
- installing sound insulation and noise dampening materials
- fitting noise suppressors to machines
- using vibration stabilising pads
- installing sound-proof partial enclosures, barriers, shields, noise cancelling curtains
- installing acoustic baffles (for large surface areas, a spray-on treatment may be more economical)
- changing the work process or design:
- use bending machines, pressing methods or glue instead of hammers.
- lower materials carefully instead of dropping. Reduce drop heights for materials that must drop and place absorbent material (e.g. sponge) in landing area
- use mains powered electrical equipment instead of diesel generators
- use laser cutting in place of grinding or punching
- use hydraulic breaking or bursting techniques rather than pneumatic impact breaking methods for demolition
- use bored piling rather than hammered piling
- turn down the volume, change fan speeds
- improve crane configuration and storage arrangements
- line steel trestles and benches, product bins and scrap bins with wear-resistant rubber (Note: alternative earthing
- arrangements may be needed).
- place work pieces on a durable rubber mat instead of hard bench or floor
- extend the guarding and line with acoustic dampening material, where practicable
- provide quiet rooms for rest breaks that are fully enclosed with well-sealed doors and windows to reduce background noise levels as far as possible
The least effective controls in the hierarchy are administrative actions and personal protective equipment (PPE) because they:
- do not stop hazardous noise at the source or in its pathway like the higher-level controls
- rely on worker compliance and behaviour, and
- require a lot of supervision to ensure worker compliance.
Administrative actions should provide a systematic framework that support the higher level WHS controls used and include:
- establishing a 'buy quiet' policy to prevent sources of hazardous noise from entering your workplace. Establish acceptable noise criteria for new equipment. When purchasing new plant, include them in any purchase specifications and tendering process. Obtain noise emission data before purchasing to choose the quietest available and affordable plant
- providing quiet lunch and rest areas with low background noise levels where workers can spend their breaks away from noise
- developing safe work procedures in consultation with workers and enabling them to undertake work activities safely, e.g.
- rotate workers to reduce individual exposure times
- restrict access to noisy areas
- proper maintenance program for plant, equipment and tools
- schedule activities involving hazardous noise to be done outside of normal hours or on shifts with fewer workers present, where possible
- Workplace noise assessments to identify hazardous noise sources and recommended controls. SafeWork NSW recommends noise assessments are done in noisy workplaces.
They should be carried out whenever there is:
- installation of new, or removal of, machinery
- a change in workload or equipment operating conditions that are likely to cause a significant change in noise levels
- a change in building structure that’s likely to affect noise levels
- modification of working arrangements that affect the length of time workers would spend in a noisy work environment
In order to get a true indication of a worker’s exposure, the PCBU needs to take both personal and general workplace noise measurements whilst equipment is being operated.
A workplace noise assessment will provide the necessary information for you to:
- identify the workers who are exposed to hazardous noise
- identify the machines and processes that are generating hazardous noise
- work out which high level controls will be the most effective
- also work out what level of hearing PPE that may be required for any leftover risk
SafeWork NSW recommends that the noise management plan includes a systematic workplace hearing conservation program to protect workers from the risk of hearing loss.
Hearing personal protective equipment (PPE)
Hearing PPE is the last and the least effective control in the hierarchy and should only be used to manage any risk that is leftover after all higher-level controls have been implemented.
Based on the workplace noise exposure levels and the target in-ear noise exposure level, the workplace assessment will determine what level of hearing protection will correctly reduce (attenuate) the noise intensity received in a worker’s ear to the required 80dB(A) in-ear noise exposure level.
All hearing PPE should be:
- tested and approved in accordance with Australian Standard AS/NZS 1270:2002: Acoustics – Hearing protectors. Test results are found on the packaging of the hearing protector
- selected and maintained in accordance with AS/NZS 1269.3:2005 Occupational noise management – hearing protector program
When selecting personal hearing protection, you should consider:
- the worker
- the level of workplace noise
- the target in-ear noise exposure level
- the degree of attenuation required
- the comfort, weight and clamping force of the hearing PPE
- the suitability of the hearing PPE for both the worker and the environment
- its compatibility with spectacles and other protective equipment used by the worker, like hard hats, respirators and eye protection
Always involve your workers in the selection process and offer a reasonable choice from a range of types. Where necessary, obtain professional advice when selecting.
Other considerations for hearing protection are:
- Do not provide hearing PPE that under-protects or over-protects a worker’s hearing
- Workers must always wear hearing PPE whenever they are exposed to hazardous noise
- Never use audio headphones as a substitute for hearing PPE
- Hearing PPE must be regularly inspected and maintained
- Workers must be trained in the proper use, fit, care and maintenance of personal hearing protectors
Read hearing personal protective equipment for more detailed information when considering the correct level of hearing protection.
Maintenance and review
Once you have implemented control measures to protect health and safety by managing the risk of noise in your workplace, you must maintain and review them to ensure they remain fit for purpose, suitable for the nature and duration of work and be installed, set up and used correctly and reviewed regularly to make sure they are effective.
Specific moments to conduct a review include when:
- the control measure is no longer effective
- before a change at the workplace is being planned
- a new or relevant hazard or risk is identified
- the results of consultation indicate a review is necessary, or
- a health and safety representative request a review.
Common review methods include workplace inspection, consultation, testing and analysing records and data. You can use the same methods as in the initial hazard identification step to check control measures. You must also consult your workers and their health and safety representatives.
The Code of practice for managing noise and preventing hearing loss at work provides further information on the requirements and considerations for maintaining and reviewing control measures.