Controlling hazardous noise in the construction industry
Exposure to hazardous noise at work is a major cause of hearing loss for workers in a number of industry sectors across NSW.
For the period 2012 – 2015, the construction industry sector ranked second highest, with workers lodging 17% of the total workers compensation claims for Noise Induced Hearing Loss (NIHL).
Clause 56 of the WHS Regulation 2017states the acceptable level of noise that any worker can be exposed to in the workplace is 85 decibels (dB) averaged over an eight-hour period (referred to as dB(A)). All noise above this level is considered hazardous noise.
A good rule of thumb is: If you have to raise your voice to be heard, the noise level is likely to be 85 dB(A) or more.
It’s important to know that noise doesn’t have to be painful to be doing damage to the human ear.
Exposure to hazardous noise can cause temporary or permanent NIHL and tinnitus (ringing in the ears). Hazardous noise damages the hair cells in the inner ear – and, once they are destroyed, they never grow back.
Some very loud noises, such as explosive powered nail guns, firearms, stamping presses and forges, can damage your hearing instantly. This is known as acoustic trauma.
The impact of increasing noise
Zero decibels (0 dB) is the quietest sound audible to a healthy human ear. From there, every increase of 3 dB represents a doubling of noise intensity. For example: noise measured at 88 dB(A) is double the intensity of noise measured at 85 dB(A).
The risk of suffering damage resulting in hearing loss increases with prolonged or additional exposure to the noise.
There are many noisy tasks involved in construction work, which means that workers may be exposed not only to the noise that their work is making, but also to the ambient, or background, noise that others tasks are making on site.
The workers at risk of serious injury include those using:
- impact equipment and tools (for example: piling hammers, concrete breakers, manual hammers)
- explosives (for example: blasting, cartridge tools)
- pneumatically powered equipment (for example: nail guns)
- plant powered by internal combustion engines
Other workers who may be at risk include:
- workers in the vicinity of noisy plant
- operators and others in enclosed spaces where there are noisy activities or lots of machinery
- service and equipment maintenance workers
Who is responsible for controlling hazardous noise?
- It is important to understand that occupational noise and environmental noise are two separate issues. They must be considered individually, as well a together
- Persons conducting a business or undertaking (PCBUs) who own, hire or operate plant or equipment in the construction industry must ensure as far as reasonably practicable that the plant or equipment operates below the noise exposure standard.
- PCBUs involved in the management or control of workplaces must also ensure that all plant or equipment operates below the noise exposure standard so far as is reasonably practicable.
It is recommended that the requirements are included into documented contractual agreements with all parties.
- All PCBUs involved at the work site must, so far as is reasonably practicable, consult, co-operate and co-ordinate activities with each other.
- Workers have a duty to take reasonable care for their own and others health and safety and co-operate to make the workplace safe. This includes following WHS policies and procedures and wearing hearing protection if provided.
A practical framework to manage hazardous noise in the construction industry
- Noise levels are controllable and some measures are more effective than others at controlling hazardous noise.
- The Work Health and Safety Regulation 2017 requires using the highest level of control that is reasonably practicable. The focus is to reduce the noise level down to below, or equal to, 85 dB(A).
- Involve your workers when considering noise controls because they often know about particular noise problems on-site and can offer possible solutions.
Effective and practical action can be taken to manage hazardous noise in every stage of the construction process – including before the work even starts on site, for example:
Stage 1 - client's specifications
The client should include their workplace noise control requirements in a client specification list in the tender document to help avoid unexpected costs during the construction phase. It also allows tenderers to plan how to overcome noise problems in advance.
The client’s specifications may include:
- specified noise exposure levels during the construction phase, meeting the exposure standard as a minimum
- using quiet/silenced equipment
- adopting quieter, alternative techniques
- using noise control measures like silencers, barriers, enclosures
- erecting warning signs to identify hazardous noise areas
- using time restrictions, and
- providing personal hearing protection and training.
Stage 2 - tenderer's proposal
The tenderer’s proposal should address all of the client’s specifications by preparing an occupational noise management plan that is included in their site specific safety management plan detailing the actions required to achieve the specified noise exposure levels.
The occupational noise management plan should be based on the results of any noise assessment and should also include:
- measuring noise levels to confirm that control measures are a achieving expected attenuation
- specifications for purchasing or hiring plant
- a description of any training and supervision that may be needed
- control measures for temporary work areas and situations
- timeframes for reviewing noise assessments and control measures
It may also include information on how the tenderer is planning to meet its obligations, such as:
- a list of equipment to be used - with noise levels at operator and other relevant worker positions
- the methods proposed to lower noise exposure, foe example barriers, enclosures, maintenance
- restricted hours; rotation of workers in noisy areas; limit number of workers onsite during activities that generate hazardous noise
- signage warning of noisy equipment and processes site induction for workers and contractors to include noise levels, noise controls and correct use and maintenance of personal hearing protectors selection and provision of appropriate personal hearing protection.
Stage 3 - planning of site
The main contractor should plan to co-ordinate subcontractors so that the activities of one do not unnecessarily expose workers of another to hazardous noise.
It is good practice to prepare an occupational noise management plan for this stage and nominate one person as the noise coordinator for all noisy activities.
Site planning should include:
- preparation of schedules of noisy plant and exposure estimates for each phase of work
- laying out the site to separate noisy activities from quieter ones
- scheduling noisy activities to take place when the minimum number of nearby workers are present (environmental noise restrictions need to be considered to avoid neighbourhood annoyance)
- rostering workers to minimise exposure times
- preparation of guidance for workers on hazards and the methods to reduce noise
- ensuring that workers are well trained, instructed and supervised in noise matters and responsibilities including correct use and maintenance of personal hearing protectors.
Stage 4 - construction stage
Once the construction work is in progress, it is essential to monitor the implementation of the occupational noise management plan.
This could be carried out by the client or the main contractor and could include the following:
- checking if equipment brought onto site complies with specifications, for example by obtaining information available from suppliers or by onsite noise assessments. Avoid equipment that is either over or under powered.
- reducing noise from identified noise sources by exchanging equipment and/or processes for a quieter alternative or by using engineering controls to quieten the existing one
- ensuring that all plant is properly maintained, for example all noise control measures like silencers and enclosures are intact
- monitoring work schedules to check that noisy work is carried out as specified, away from other workers, outside hours, etc
- monitoring if noisy areas are identified. Make sure these areas are well marked so workers and contractors can avoid entering them unnecessarily
- monitoring whether training has been carried out and if personal hearing protection is adequate, and being worn and maintained correctly
- holding daily safety toolbox meetings to provide and obtain feedback on the effectiveness of noise control measures and personal hearing protection from workers and contractors posting noise information on safety notice boards.
Practical noise control solutions
- On sites with more than one contractor, it is essential that they all consult and communicate with each other.
- Before you buy or hire plant or equipment, ask yourself (or your supplier) if there is a quieter way of doing the job.
- You should use the highest level control that is reasonably practicable, based on the hierarchy of controls. Frequently, a combination of controls may be required.
- Due to the difficulties in completely eliminating noise during construction activities, the most effective control measures are usually substitution, isolation and engineering controls. Work on construction sites changes frequently so you must regularly review the control measures in place and amend them as necessary.
- use plant and equipment with lower noise emissions
- use a quieter work method instead of a noisy one, for example:
- hydraulic breaking or bursting techniques rather than pneumatic impact breaking methods for demolition
- gas cutters to cut metal rather than using grinding methods to dismantle metal structures
- pressing methods rather than hammering
- bored piling rather than hammered piling
- mains powered electrical equipment instead of diesel generators
- replacing vehicles with electric or gas powered alternatives.
- locate noisy plant (eg: generators, compressors, pumps and concrete batching plant) as far as possible from sensitive boundaries and main work areas, as work allows
- isolate the noise source in an insulated room or enclosure, eg: box compressors
- isolate the worker from the noise source by using remote-controlled plant or placing them in enclosed operator locations, eg: a noise enclosed cabin or booth
- move the noisy work activity away from others.
- place equipment on dampening material to reduce noise (not directly onto concrete)
- isolate vibrating parts
- fit silencers and baffles to your machinery and combustion engines. Ensure they are in good condition and work effectively
- fit muffling to mobile equipment, eg: hand-held concrete breakers
- use noise reduced saw blades
- use barriers made of absorptive materials to reduce reflected sound;
- use floating slab measures to control ground-borne noise and vibration
- use partitions or screens to deflect or absorb sound.
Additional specific control measures for common construction work activities are detailed in Appendix 1.
- check the noise levels of plant and machinery before purchase. Trial equipment where possible.
- regularly service vehicles and machinery – as parts become worn, noise levels can change. Well maintained equipment will make less noise and is also less likely to break down.
- develop safe work procedures to reduce noise from your plant and vehicles that may include:
- turning off engines or reducing them to idle when they are not in use
- checking and reporting if the brakes are properly adjusted or ‘squeal’; checking engine oil levels regularly
- not revving the engine unnecessarily
- only using the horn in emergencies
- keep machinery covers and panels closed when in use, ensuring they are well fitted
- keep bolts/fasteners tightly secured to avoid rattles
- check for noise problems. Do workers have to shout at arm’s length to communicate?
- restrict access of unauthorised people to noisy areas
- organise work schedules so worker exposure to hazardous noise is limited, rotate worker activities
- minimise the use of vehicle reversing alarms, for example: set up a one-way driving system on your site. Consider fitting a broadband reversing alarm, as this can reduce the level of noise that is generated on site
- Training is an important administrative noise control and should be as specific as possible about all noise control measures for the site and how to use them safely.
Persons requiring training include:
- those writing the tender documentation to ensure that contractors will control noise;
- managers, so that they can meet their duties regarding control and record keeping;
- workers, who need to know how and why to use work equipment and control measures to minimise exposure to noise. Particular attention should be paid to workers who are new, young or vulnerable.
Personal protection equipment
- hearing PPE must only be used as a last resort, to manage any leftover risk after all practicable higher-level control measures have been taken but the reduced noise is still above the exposure standard. This is because hearing PPE merely attempts to protect the worker’s hearing – it does NOT prevent their exposure to hazardous noise.
- PPE can fail or be inefficient without it being visibly obvious.
- hearing protection only works when used, and its effectiveness is also reliant on its condition and whether it is fitted correctly. If hearing PPE is required, the PCBU responsible must make sure they are chosen for their:
- noise reduction characteristics,
- suitability for the job, and
- compatibility with other protective equipment
- they must be appropriate for the noise level and the worker. A variety of comfortable hearing PPE should be made available so workers can then choose between the different types, making the PPE more likely to be worn. Any PPE used for noise protection should be approved in accordance with relevant Australian Standards and selected in consultation with workers or their representatives.
- if hearing PPE is provided, the PCBU responsible must provide adequate supervision, training and instruction to their workers on the correct use, maintenance and storage of the PPE
- they must also make sure that the workers understand that they have to wear the PPE provided and wear it correctly (for example, headbands go over the head not around the neck; foam ear plugs should be rolled and compressed well before insertion).
- regular supervision must include ensuring that workers are wearing their PPE and you should immediately replace any damaged hearing PPE, such as damaged, hard or worn muff seals.
- in order to get the full protection, workers must wear their hearing PPE at all times during a noisy shift. If they remove them, even for a short duration, their protection will be substantially reduced. Managers and foremen should always set a good example by always wearing their hearing PPE.
- Work Health and Safety Regulation 2017, Part 4.1 – Noise
- Managing noise and preventing hearing loss at work code of practice
- Work health and safety consultation, coordination and cooperation code of practice
- AS/NZS 1269.1:2005 Occupational noise management—Measurement and assessment of noise immission and exposure
- AS/NZS 1270:2002 Acoustics – Hearing protectors
- National Acoustic Laboratories - ph: (02) 9412 6800