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Hazardous noise and hearing loss at work: The facts

Noise is a known workplace hazard

Exposure to workplace hazardous noise can cause permanent hearing loss in workers, which destroys their ability to hear clearly. It makes it more difficult for them to hear sounds, including those that are necessary to work safely, such as verbal instructions – even warning signals.

There is strong evidence indicating that exposure to vibration can exacerbate the effects of noise on hearing. Workers who are exposed to noise and vibration together may be more likely to suffer from hearing loss

You must manage the risks of hearing loss from exposure to noise and vibration by following a systematic process that involves:

  • identifying sources of noise that may cause or contribute to hearing loss
  • if necessary, assessing the risks associated with these hazards
  • implementing risk control measures, and
  • reviewing risk control measures

You can obtain further guidance about hazardous noise, vibration and hearing loss by reading:

The human ear has three separate parts

There are three parts to the ear:

The outer ear contains the eardrum and also glands that secrete wax to stop dust particles from reaching it.

In simple terms, a person hears by:

  • sound waves travelling into the ear canal until they reach the eardrum
  • the eardrum then vibrates and passes the vibrations through the middle ear bones (the hammer, anvil and stirrup) into the cochlea
  • inside the cochlea, the tiny hair cells rock back and forth and change the vibrations into nerve impulses (electrical signals)
  • the fluid inside the cochlea causes the hair cells to carry messages to the auditory (hearing) nerve, that are then sent to the brain, then
  • the brain tells you that you are hearing something and what those sounds are

Hearing loss is caused by exposure to noise that exceeds the ‘exposure standard for noise’

Clause 56 of the WHS Regulation 2011 states the meaning of the exposure standard for noise.

There are 2 criteria for the exposure standard for noise:

  1. a total (continuous) noise that exceeds 85 dB when averaged over an 8-hour period (known as 85dB(A)), and
  2. a noise that exceeds a peak noise level of 140 dB(C)

There are 2 criteria because hazardous noise can cause 2 types of hearing loss:

  1. gradual hearing loss – called noise induced hearing loss (NIHL) – happens over a period of time, caused by noise that exceeds 85dB(A)
  2. immediate hearing loss – called acoustic trauma – can be caused by noise that exceeds 140dB(C), eg: noise generated by an impact or explosive power tool

Both types of hazardous noise are separate risk factors and should be treated as such.

The Managing noise and preventing hearing loss at work code of practice has further guidance.

Hazardous noise in the workplace can be caused by a number of sources

Workplace hazardous noise can be created by:

  • mechanical impacts
  • high-velocity air flow
  • high-velocity fluid flow
  • vibrating surfaces of plant and/or equipment (eg: vehicle cabin; a hand-held tool)
  • vibrating surfaces of the product being manufactured, and
  • external sources, such as traffic (for truck drivers, couriers, etc)

IMPORTANT NOTE: Workplaces with hard, non-absorbent floor, wall and ceiling surfaces, can increase a worker’s exposure to the risk of hearing loss from reflected noise, which is noise that bounces off the hard surfaces back into the workplace – exposing workers to further harm. Examples of hard, non-absorbent surfaces include concrete, marble, metal, tiles, wood, etc.

Many workers in the hospitality industry are at increased risk of exposure to reflected noise, due to the very popular trend of hard, industrial décor. And the risk to workers is increased even further in venues with loud music, such as nightclubs, hotels, etc.

There is a simple way to indicate if your workplace is too noisy

A primary indicator that the noise in your workplace may be hazardous to hearing is when a person has to raise their voice to talk to someone 1m away.

There are three high-risk risk industry sectors for hearing loss

The top three industry sectors for hearing loss workers compensation claims are:

  • manufacturing,
  • construction, and
  • transport / postal / warehousing

Combined, these three industries account for more than half (approx. 52%) of all workers compensation claims lodged for hearing loss.

Some examples of hazardous noise sources

Examples of common noise sources – both at work and non-work related – include:

85

Noisy restaurant (85 – 90)

Garbage disposal (85 – 95)

90

Tractor;

Underground train station  (90 – 115)

95

Electric drill

Motorcycle (95 – 110)

100

Factory machines

110

Power saw

Leaf blower

Baby crying

Symphony performance

Disco / Band / Rock concert (110 – 120)

120

Hammer hitting nail

Ambulance siren

130

Percussion section at symphony

Car  and dragster  races (130 – 155)

140

Airplane taking off

150

Artillery fire at approx. 150m

Jet engine taking off

163

Rifle

166

Handgun

170

Shotgun

180

Rocket launch

PCBUs must comply with Part 4.1 of the WHS Regulation 2011 to manage noise (Clauses 56 – 59)

Part 4.1 of the WHS Regulation 2017 (the Reg) details PCBU duties for managing noise:

  • Clause 56 details the meaning of the term exposure standard for noise, which are 85dB(A) and 140dB(C).
  • Clause 57 requires PCBUs to comply with Part 3.1 of the Reg to manage the noise risks and states PCBUs must ensure that workers are not exposed to workplace noise that exceeds the exposure standard.
  • Clause 58 details the requirement for PCBUs to provide audiometric testing for workers who are frequently required to use hearing personal protective equipment (PPE) to protect them from the risk of noise induced hearing loss (NIHL) caused by noise that exceeds 85dB(A).

Clause 58 is exempted for all NSW businesses until 1 January 2019 .

  • Clause 59 details specific duties for designers, manufacturers, importers and suppliers of plant.

Eliminating noise in the early stages of product planning and design is much more effective and usually cheaperthan making changes after noise hazards have been introduced into the workplace.

Designers, manufacturers, importers and suppliers of plant must also give adequate information to each person to whom they supply the plant, concerning:

  • each purpose for which the plant was designed or manufactured, and
  • the results of the calculations, analysis, testing or examination, and
  • any conditions necessary to ensure that the plant is without risks to health and safety when used for a purpose for which it was designed or manufactured

Doing what is reasonably practicable is specific to you and your business

You must always try to eliminate and reduce, so far as is reasonably practicable, any health and safety risks in the workplace – including those associated with exposure to hazardous noise.

‘Reasonably practicable’ means doing what you are reasonably able to do, following a systematic risk management process that focuses on the hierarchy of controls, to control identified risks and ensure the health and safety of your workers.

Basically, ‘reasonably practicable’ means doing the most that you can do, using the hierarchy of controls from top to bottom, to ensure workers at your business are not exposed to risks to their health and safety. Cost may be relevant but you can only consider this after all other factors have been taken into account.

The Australian Standard 1269 series, Occupational noise management, provides useful technical guidance to assist with managing workplace noise

The Australian Standard AS/NZS 1269 series, Occupational noise management (1 – 4), provides technical requirements and guidance on all facets of occupational noise management.

AS/NZS 1269.1:2005 Measurement and assessment of noise immission and exposure is referenced in Clause 56 of the WHS Regulation 2017, which means it must be used to measure workers’ exposure to workplace noise. In addition, this Standard:

  • describes the types of noise assessments which may be required
  • details suitable noise measuring instruments to carry them out
  • details the procedures for noise measurement, and
  • provides information about:
  • ototoxic agents
  • the adjustment factor required to measure exposure from for extended shifts
  • the weekly averaging procedure for workers work more than five days per week

AS/NZS 1269.2:2005  Noise control management outlines noise control management strategies that should be implemented in both existing and proposed workplaces.

AS/NZS 1269.3:2005 Hearing protector program is referenced in the Managing noise and preventing hearing loss at work Code of Practice (COP). All NSW businesses should follow the advice contained in approved COPs, unless there is an alternative course of action that achieves the same – or better – standard of health and safety in the workplace.

This Standard:

  • outlines the administrative responsibilities associated with a hearing protector program
  • discusses the selection, use and maintenance of various types of hearing protectors, and
  • gives information on training and motivation in regard to hearing protector programs

AS/NZS 1269.4:2014 Auditory assessment specifies the procedures and requirements for the audiometry testing of workers. It is also referenced in the COP so, again, you should follow the advice contained in the COP, unless there is an alternative course of action that achieves the same – or better – standard of health and safety in the workplace.

AS/NZS 1270:2002  Acoustics – Hearing protectors specifies requirements for the design, materials and performance of conventional hearing protectors.

It also provides guidance on the general requirements for, and the physical and acoustic testing of, specialist hearing protectors.

Suppliers of hearing protectors should provide the full information on the attenuation likely to be provided including the SLC80 ratings, class and octave band attenuation values. The attenuation values should be derived from attenuation measurements made in accordance with AS/NZS 1270.

A workplace noise assessment will identify noise sources that expose workers to the risk of hearing loss

The Managing hazardous noise and preventing hearing loss at work Code of Practice advises where you have identified any noisy activities that may expose your workers or other people at your workplace to hazardous noise then, unless you can reduce the exposures to below the standard immediately, you should assess the risks by carrying out a noise assessment.

Workplace noise assessments should be carried whenever there is:

  • installation of new, or removal of, machinery
  • a change in workload or equipment operating conditions likely to cause a significant change in noise levels
  • a change in building structure likely to affect noise levels
  • modification of working arrangements affecting  the  length of time workers would spend in noisy  workplaces

Workplace noise assessments can be:

  • simple, involving only a single noise source, or
  • complex, eg:
    • where multiple noise sources are involved and pose a high risk to a significant number of workers
    • workplaces with variable noise levels over a shift, and
    • jobs where workers move in and out of noisy areas

A noise assessment will help you:

  • determine what noise sources and processes are causing that risk
  • target high-risk areas and tasks within your workplace
  • identify which workers are at risk of hearing loss and whether the length of their shifts is impacting on their exposure to hazardous noise at the workplace
  • identify practicable, high-level control measures, focusing on the hierarchy of controls, to reduce the level of noise being generated
  • check the effectiveness of your existing control measures, in both their design and operation
  • identify if any new work methods or new plant have made the work noisier

All businesses should follow the advice in approved COPs, unless there is an alternative course of action that achieves the same – or better – standard of health, safety and welfare in the workplace.

Workplace noise assessments must be done by a competent person

The Managing hazardous noise and preventing hearing loss at work Code of Practice (COP) advises that a noise assessment should be done by a competent person in accordance with the procedures in Australian Standard AS/NZS 1269.1 Measurement and assessment of noise immission and exposure.

The more complex the situation, the more knowledgeable and experienced the person needs to be.

AS/NZS 1269.1 states a competent person is one who:

  • has accurately calibrated noise measuring instruments, and
  • through training and experience:
    • understands what is required by the WHS Regulation 2017 to control noise in the workplace
    • knows how to check the performance of the instruments
    • knows how to take the measurements properly
    • can interpret the results of the noise measurements

The way a noise assessment is done depends on a number of factors, including:

  • the type of workplace
  • the number of people potentially at risk from exposure to hazardous noise, and
  • the information already available on noise at the workplace

The more complex the situation, the more knowledgeable and experienced the person needs to be, eg: an acoustical consultant or occupational hygienist. To obtain the services of either, contact the Australian Institute of Occupational Hygienists (AIOH) or check the Yellow Pages.

All businesses should follow the advice in approved COPs, unless there is an alternative course of action that achieves the same – or better – standard of health, safety and welfare in the workplace.

Workplace noise assessment reports should detail specific information

Workplace noise assessment reports should show that the assessment was done properly and that all factors were taken into account. It should contain all of the following information:

  • date of assessment
  • name of assessor, their background and qualifications
  • type of equipment used to take measurements, including  calibration details
  • locations of measurements (ie: general area; operator ear position) and measurement timeframes
  • the area, plant, process, activity, operating conditions and workers that were assessed, with a brief description of the work activity and how it’s done
  • the sources of hazardous noise (plant / process / jobs), and whether all the noise sources that were operating at the time were taken into account
  • the length of workshifts (eg 8-hour or 12-hour shift)
  • the results of measurements in terms of noise levels and durations
  • interpretation of the results (ie: compared to exposure standards; what do the results mean etc.; ranking of noise sources)
  • action required, ie: any obvious noise controls that could be implemented, or the need for more detailed noise control study
  • other relevant factors, including:
    • information on and adequacy of any control measures already in place and hearing protectors used during the assessment
    • where relevant, information about the environment (types of walls, surfaces, buildings, operational state of machinery, etc.)

Then – use the noise assessment report to assist with selecting appropriate control measures.

High-risk industry sectors should implement an occupational noise management plan to manage hazardous noise

SafeWork NSW strongly recommends high-risk workplaces, particularly those in the manufacturing, construction and transport / postal / warehousing industry sectors,develop an occupational noise management plan to:

  • effectively manage the risks of workers being exposed to hazardous noise
  • protect them from the risk of hearing loss, and
  • assist to effectively monitor the chosen noise control measures you have used

The occupational noise management plan should be based on the results of the workplace noise assessment and should include:

  • measuring noise levels to confirm that the control measures are working
  • a description of any training and supervision that may be needed
  • any interim control measures for use in temporary work areas and situations, and
  • timeframes for reviewing noise assessments and control measures

The plan should also identify:

  • what actions need to be taken,
  • who will be responsible for taking the actions, and
  • by when

Relevant industry sectors must understand that environmental noise and occupational noise are different hazards – and they are measured differently

Many PCBUs (eg: in the construction and related industry sectors) already undertake environmental noise monitoring and develop environmental noise management plans, as required by the Department of Environment and Climate Change (DECC) and Environmental Protection Authority (EPA). Environmental noise relates to neighbour and community noise concerns.

Most environmental noise management plans will include a small section about occupational noise management however, this information is normally an overview of the PCBUs duties in relation to the WHS legislation – not what they are actually planning to do to manage and control workers’ exposure to hazardous noise.

Environmental noise management plans rarely, if ever, detail specific information on how the PCBU will manage workers being exposed to hazardous noise (that is, noise that exceeds the exposure standard for noise) or its associated risks.

Relevant industry sectors should consider environmental noise and occupational noise together, as well as independently of each other.

SafeWork NSW strongly recommends high-risk workplaces, particularly those in the manufacturing, construction and transport/postal/warehousing industry sectors,develop an occupational noise management planto:

  • effectively manage the risks of workers being exposed to hazardous noise
  • protect them from the risk of hearing loss, and
  • assist to effectivelymonitor the chosen noise control measures used

An occupational noise management plan should be based on the results of the workplace noise assessment and should include:

  • measuring noise levels to confirm that control measures are working
  • a description of any training and supervision that may be needed
  • any interim control measures for use in temporary work areas and situations, and
  • timeframes for reviewing noise assessments and control measures

The plan should also identify:

  • what actions need to be taken,
  • who will be responsible for taking the actions, and
  • by when

Workplaces where noise is likely to exceed the exposure standard should establish a hearing conservation program

The aim of a hearing conservation program is to protect workers from the risk of hearing loss and should contain the following key elements:

  • a risk management framework – identify noise hazards, assess their risks, control the risks and then regularly review
  • details of the information and training required to be provided to affected workers
  • regular audiometric testing for affected workers, and
  • an effective record keeping system

Consider incorporating the hearing conservation program into your occupational noise management plan.

Despite the current exemption for all NSW businesses from the requirement to provide audiometric testing under Clause 58(2) of the WHS Regulation 2017 (which is in force until 1 January 2019), SafeWork NSW considers audiometric testing plays an important part in any hearing conservation program.

Audiometric testing is a measurement of hearing loss that may have occurred as a result of exposure to hazardous noise in the workplace.

Notwithstanding the current exemption for all NSW businesses from the requirement to provide audiometric testing underClause 58(2) of the WHS Regulation 2017(which is in force until 1 January 2019), SafeWork NSW considers audiometric testing plays an important part in any hearing conservation program by helping to identify hearing loss and other problems, so they can be prevented from developing further.

It is also a very valuable tool to assist you monitor the effectiveness of the noise controls you have implemented to protect workers from hearing loss – particularly in the 3 high-risk industry sectors, which are manufacturing, construction and transport / postal / warehousing.

While it isn’t a preventative measure, establishing an audiometric testing schedule can be of great benefit for you and your business if a worker lodges a workers compensation claim for hearing loss because:

  • the initial audiometric test identifies if new workers (or those changing jobs) have any hearing deficit before commencing the work – especially in high-risk industry sectors, and
  • regular follow-up audiometric testing provides you with certainty as to how much hearing loss a worker has experienced (if any) whilst employed by you

And, where a PCBU can demonstrate that a worker did not experience any loss whilst in their employment, then ultimate liability for their workers compensation claim may be avoided.

In addition, regular audiometric testing:

  • is a valuable check on the success of your workplace noise controls and noise management strategy, and
  • provides an opportunity to educate workers about noise awareness

A single exposure to hazardous noise can cause temporary hearing loss

A single exposure to loud noise can damage the hair cells  in the inner ear (cochlea) temporarily, causing temporary hearing loss that may also be associated with tinnitus (ringing in the ears):

  • it may last a number of hours, but normally recovers within 24 hours, however the duration can vary depending on the degree of exposure
  • normal hearing is usually restored after a period of time away from the loud noise

You may have experienced temporary hearing loss after being at a loud concert, shooting range; drag car racing event or football grand final.

The more exposure a person has to hazardous noise, the more damage is done – and it is permanent

The harmful effects of hazardous noise are cumulative, which means the damage causing hearing loss increases over time through a series of additions.

And, once a hair cell dies, it can’t be replaced or repaired by any current medical treatment or technology. Hearing aids only offer limited benefit – they don’t restore “normal” hearing.

Also, there are many injured workers whose hearing loss – whether temporary or permanent – may not be the only problem. Their hearing loss may also be accompanied by tinnitus, which can involve one, or a combination, of continuous and intrusive sounds and is incurable, just like the damage caused by NIHL and acoustic trauma.

Noise induced hearing loss (NIHL) happens gradually – many people don’t realise they have it until it is too late

The harmful effects of hazardous noise are cumulative, which means the damage causing hearing loss increases over time through a series of additions.

With each further exposure a person has to loud noise, the hair cells in the cochlea (inner ear) will graduallylose their ability to recover, become non-responsive to sound and will eventually die – causing permanent hearing loss.

The effects of NIHL can take some years to be noticed.

At first, the person isn’t aware of any change in their hearing but, over time, it becomes more noticeable, eg: a worker may have difficulty hearing what family and co-workers say clearly or hearing sounds that are necessary for working safely, like verbal instructions – even warning signals.

The degree of hearing damage is dependent on:

  • the level/s of noise a person is exposed to,
  • how often and how long they have been exposed to the noise, eg: workers who are exposed to hazardous noise on a daily basis at work are at a far greater risk of developing NIHL, and
  • their susceptibility to noise

The dB(A) noise is measured in a logarithmic scale

This means that every 3dB(A) increase doubles the risk of noise induced hearing loss (NIHL).

Logarithmic scales are different to linear scales.

A good example of a linear scale is the standard school ruler, where the value between two consecutive points on the line does not change – no matter how high or low you are on it. However you look at it, the distance between the points is constant (unchanging) regardless of the location on the line.

A logarithmic scale is much different. With these scales, the value between two consecutive points not only changes, but also has a distinct pattern. Logarithmic scales give the logarithm of a quantity instead of the quantity itself. They are often used when the underlying quantity can take on a huge range of values, to reduce them down to a more manageable range. Common uses for logarithmic scales include earthquake strength, sound loudness and light intensity.

In the dB(A) logarithmic scale, a 3 decibel increase equals a doubling of the sound energy.

This means every 3 dB(A) increase in sound can cause the same damage in half the time.

Another way of looking at it is: For every 3 dB(A) increase in sound, the risk of hearing loss is doubled.

In relation to dB(A) noise, the exposure standard is a total (continuous) noise that exceeds 85dB when averaged over an 8-hour period, identified as 85dB(A) and workers are at risk of hearing loss if exposed to noise that exceeds this level.

If a worker is exposed to 88dB(A), they receive TWICE the noise energy as a worker who is exposed to 85dB(A). This means:

  • the worker can only be exposed to 88dB(A) for 4 hours of an 8 hour shift
  • the remaining 4 hours of their shift must be worked in an environment that is below 85dB(A)

If the worker is exposed to 88dB(A) for more than 4 hours, the exposure standard has been exceeded.

And, if a worker is exposed to 91dB(A), then their exposure time must be halved again to 2 hours, and the remaining 6 hours of their shift must be worked in an environment that is below 85dB(A). If the worker is exposed to 91dB(A) for more than 2 hours, the exposure standard has been exceeded.

And if they’re exposed to 94dB(A), their exposure time must be halved again to 1 hour, with the remaining 7 hours of their shift worked in an environment that is below 85dB(A).

And so on, and so on.

3dB(A) may seem like a small number but it can have a huge impact because every increase of 3dB(A) can cause permanent damage to a worker’s hearing twice as quickly.

Acoustic trauma injuries can be caused immediately from a single exposure to a peak noise level that exceeds 140dB(C)

‘Acoustic trauma’is the immediate and permanent hearing loss that can result from exposure to peak noise measured in the dB(C) scale. It is caused by impulse or explosive noises, such as explosive power tools; gun shots and fireworks (at close range).

Acoustic trauma injuries are very often associated with intense pain and in some cases the sound pressure can rupture the eardrum.

Acoustic trauma and Acoustic shock are not the same thing

Acoustic trauma is the immediate and permanent hearing loss that can result from exposure to peak impulse or explosive noise that exceeds the exposure standard for noise, which is140dB(C). It is very often associated with intense pain and, in some cases, the sound pressure can rupture the eardrum.

Acoustic shock incidents are sudden, unexpected loud noises that do not exceed 140dB(C), and usually occur during telephone headset use. The loud noises can include crackles, hisses, whistles, shrieks or high-pitched noises.

Acoustic shock injuries do not cause permanent hearing loss

Acoustic shock incidents are sudden, unexpected loud noises that do not exceed 140dB(C), and usually occur during telephone headset use. The loud noises can include crackles, hisses, whistles, shrieks or high-pitched noises.

All phone noise is electronically limited to a peak noise level of 123dB(C), meaning acoustic shock injuries are not caused by hazardous noise, but by a sudden rise in the noise levels.

The loud noises that may cause acoustic shock can come from a wide variety of sources, either within the transmission system or from the customer end. The sources can include:

  • faulty or damaged networks, telephones and headset equipment
  • broadband and narrowband interference
  • mobile phones or fax machines used in call centres
  • feedback oscillation from some cordless phones
  • alarm signals
  • phone receivers slammed down or dropped
  • tones from misdirected facsimiles and modems
  • noises made close to the receiver (eg: whistling)

Acoustic shock symptoms

The effect on individuals can vary greatly for the same increase in sound level.

Only a small number of people develop symptoms from an acoustic incident and why a person experiences symptoms after an acoustic incident is not known with certainty. Some researchers believe that a combination of stress and sudden loud noise causes excessive contraction of the middle ear muscles, triggering the acoustic shock symptoms.

Immediate symptoms can include:

  • a feeling of fullness in the ear
  • burning sensations or sharp pain around or in the ear
  • numbness, tingling or soreness down the side of face, neck or shoulder
  • nausea or vomiting
  • dizziness
  • tinnitus and other head noises, such as eardrum fluttering.

Latersymptoms can include:

  • headaches
  • fatigue
  • feeling off-balance
  • hypersensitivity to noise, ie: a sensitivity to previously tolerated sounds such as loud voices, television and radio
  • anxiety

Control measures

To eliminate or minimise the risk of acoustic shock injuries, you should:

  • provide high quality headsets with acoustic shock protection devices
  • give prompt attention to damaged equipment and network faults. Contact the equipment or network supplier, or an acoustic specialist if necessary
  • of headsets
  • reduce background noise in the room
  • provide information and training to workers on how to:
    • -properly fit, use and maintain their headsets
    • detect warning sounds (eg: a cordless phone being used too close to the base station at the customer’s end); and
    • know when to remove headsets as quickly as possible, where necessary
  • prevent mobile phones from being used in call centres

Controlling background noise in call centres:Possible control measures to implement include to:

  • review the design and layout of the room and workstations: reduce external and building service noise
  • reduce reverberation within the room by using sound absorbing materials on floors, walls and/or ceilings
  • place acoustic barriers around / between workstations and other call centre areas
    • encourage people to not talk loudly or hold discussions near operators
    • locate fax machines, photocopiers and printers away from operators
    • control radio noise and use of mobile telephones
    • with hot-desking, ensure changeovers are smoothly managed and quiet
    • provide sufficient room for workers to move around at changeover times without crowding

Refer to the Managing noise and preventing hearing loss at work Code of Practice for more information.

The cause of a worker’s hearing damage may not necessarily just be work-related

It’s important to know that the cause of a worker’s hearing damage may not necessarily just be confined to the workplace.

Many workers can be exposed to hazardous noise during their social, sport and leisure activities, which can also damage their hearing, eg: nightclubs; personal music devices (such as iPods and car stereo systems), drag car racing; shooting ranges; etc.

Many young workers are being identified with noise-induced hearing loss (NIHL) when they first commence employment

The effects of NIHL can take some years to be noticed. At first, the person isn’t aware of any change in their hearing but, over time, it becomes more noticeable. Historically, this has resulted in many workers lodging workers compensation claims later in their working life.

However, many young workers (ie:under the age of 26 years) are now being identified with NIHL when they first commence employment.

Their hearing loss has been associated with their exposure to hazardous noise at nightclubs, bars and restaurants, as well as the enormous popularity among of personal music and other devices, such as iPods (via headphones ) and car stereo systems. It is of great concern because many young people use these devices for several hours each day – and often at high volume. However:

  • there is no Australian legislation regulating maximum noise levels for such devices
  • the devices do not contain facilities that identify or automatically ‘cut-out’ hazardous noise levels
  • manufacturers commonly provide insufficient advice about the risks of regular use at high volume

Workers compensation claims for noise induced hearing loss (NIHL) are long-term and expensive

NIHL is the single greatest cause of permanent hearing loss in Australia and also the most preventable.

BUT even though it’s the most preventable, more than 8,000 workers were affectedby noise-related injuries in NSW workplaces between 2013 and 2016, with over 90% of them left permanently disabled. The total cost of these claims was over $104 million.

PCBUs who have had NIHL claims lodged against them will certainly attest to the fact that they are VERY costly for business, due to raised workers compensation insurance premiums and other costs associated with these permanent claims resulting from:

  • a loss of productivity
  • a decrease in worker morale
  • absenteeism, and
  • staff turnover

Exposure to persistent noise – whether hazardous or not – can negatively impact your health

Exposure to persistent noise can occur at the workplace or out of the workplace.

Long-term exposure to noise can cause a person to experience many physical symptoms – whether the noise is hazardous enough to cause noise induced hearing loss (NIHL) or not. These physical symptomscan include:

  • increased blood pressure and heart rate
  • nervousness and irritability
  • insomnia
  • reduced concentration
  • hypersensitivity to noise
  • changes to hormone and cholesterol levels
  • increased stomach acid content

People may also experience psychosocial symptoms, such as isolation, depression, fatigue, etc

It is important to realise persistent noise may not be generated by external sources only – consider the people who, in addition to developing NIHL, have also developed tinnitus.

In addition to any persistant noise from an external source, these people are also exposed to persistent noise from an internal source – and that is a noise that no sufferer can escape.

As a result, many tinnitus sufferers may experience all of the above physical symptoms on a permanent basis.

Exposure to ototoxic substances can also cause hearing loss

Ototoxic substances are chemicals that can result in hearing loss.

When absorbed into the bloodstream, ototoxic substances may damage the cochlea (inner ear) and/or the auditory nerve pathways to the brain – which can lead to hearing loss and tinnitus.

Hearing loss is more likely if a worker is exposed to a combination of ototoxic substances, or a combination of the substance and noise.

There are three major classes of ototoxic substances:

1. Solvents, eg: butanol; carbon disulphide; ethanol

2. Heavy metals, eg: arsenic, lead, manganese

3. Asphyxiants, eg: acrylonitrile; carbon monoxide; hydrogen cyanide

The most common routes of entry for these ototoxic substances are via skin absorption, inhalation and, to a lesser extent, ingestion (mainly due to poor personal hygiene practices at work).

Work activities that commonly combine noise and ototoxic substances include:

  • painting
  • printing
  • boat building
  • construction
  • furniture making
  • fuelling vehicles and aircraft
  • manufacturing, particularly of metal, leather and petroleum products
  • degreasing
  • fire-fighting
  • weapons firing

Some medications have also been identified as ototoxic substances. These include some anti-cancer, anti-inflammatory, anti-thrombotic, anti-malarial, anti-rheumatic and antibiotic drugs.

Quinine and salicylic acids (such as aspirin) are also considered to be ototoxic substances.

Managing ototoxins in your workplace

The current exposure standards for chemicals and noise do not consider the increased risk of hearing loss from exposure to ototoxic substances and noise.

You must use a systematic risk management process, focusing on the hierarchy of controls from top to bottom, to manage the risks:

  • If you can’t eliminate using the ototoxic substance, you should implement reduce the risk of chemical exposure by implementing control measures such as substitution, isolation and local ventilation, supported by safe work procedures and suitable training
  • Personal protective equipment (PPE) is the least effective control in the hierarchy and should only be used to manage any risk that is leftover after the higher level controls have been implemented. Check the Safety Data Sheet for the substance to obtain information on what PPE should be used to prevent skin and respiratory absorption

The Managing noise and preventing hearing loss at work Code of Practice advises that workers exposed to ototoxins (listed in Table A.1) should:

  • only be exposed to a maximum level noise of 80dB(A)
  • be given regular audiometric testing, and
  • be given information and training on ototoxic substances

Designers, manufacturers, importers and installers of plant must provide information about the item – including about noise

The WHS Regulation 2017 (Clause 59) requires designers, manufacturers, producers, suppliers, importers and installers of plant to be used in workplaces to provide information about any hazard associated with the plant.

We know that eliminating noise in the early stages of product planning and design is much more effective and usually cheaper than making changes after noise hazards have been introduced into the workplace.

This clause requires designers, manufacturers, importers and suppliers of plant to give adequate information to each person to whom they provide the plant, concerning:

  • each purpose for which the plant was designed or manufactured
  • the results of the calculations, analysis, testing or examination, and
  • any conditions necessary to ensure that the plant is without risks to health and safety when used for a purpose for which it was designed or manufactured