Legal background and risk management

Hand holding a recording microphone

Legislation around the world defines the maximum level of noise exposure to be between 85 and 90 dB(A) for eight hours of exposure.

Legal background

Recommended noise exposure levels

Risk management programme

Initial assessment

Noise assessment

Exposure calculators and ready-reckoners

Information and training for workers

Like any other hazard in a workplace, it is important to identify the noise hazard and determine who might be affected by it. Prevention of noise-related ill-health can be achieved by employers implementing a robust risk management programme. The level and type of risk management programme depends upon the scope and extent of the problem in the workplace. However, all the risks arising from noise should be considered.

Legal background


Legislation around the world dealing with work-related noise is varied. Each country has its own unique instrument to manage workplace noise issues. Some countries provide a comprehensive set of legislation covering all aspects of workplace noise issues while others offer only minimal protection for workers from noise. Nevertheless, where introduced, almost all legislation defines the maximum level of exposed noise to be between 85 and 90 dB(A) for eight hours of exposure.

One of the most commonly-used international standards is ISO 1999:2013 – Estimation of noise-induced hearing loss. The standard specifies a method for calculating the expected noise-induced permanent threshold shift in the hearing threshold levels of adult populations due to various levels and durations of noise exposure. Some countries have developed their own technical standards that are direct copies of this ISO standard without the benefit of enabling legislation and regulation.

Several countries have also adopted recommendations made in ILO’s Working Environment (Air Pollution, Noise and Vibration) Convention 1977. The Convention prescribes measures to be taken for the prevention and control of occupational hazards in the working environment due to air pollution, noise and vibration. The ratification of this convention has resulted in similar legislation in several countries.

In Europe, the Directive 2003/10/EC (Seventeenth individual Directive within the meaning of Article 16(1) of Directive 89/391/EEC) lays down minimum requirements for the protection of workers from risks to their health and safety arising or likely to arise from exposure to noise and in particular the risk to hearing. The Directive sets exposure limit values and exposure action values with respect to the daily and weekly noise exposure level as well as peak sound pressure. It sets the maximum exposure limit as 87 dB(A) for an eight-hour day. Under the EU directive, the environment must meet the requirement for the lowest possible noise levels, taking into account modern technology.

In the United States, the Occupational Safety and Health Administration (OSHA) has introduced Regulations 1910.95 – Occupational noise exposure that set stringent national requirements on what noise can be permitted in the workplace. These regulations set the maximum permissible exposure limit to 90 dB(A) for everyone who works eight hours a day.

A similar pattern has been observed in legislation introduced in “developed” countries such as Norway, Sweden, France, Spain and New Zealand, allowing 85 dB(A) for an eight-hour day with an exchange rate of 3 dB(A). However, other countries have adopted the legislation set by developed nations, without considering the local circumstances and work practice, resulting in lower levels of protection from the noise hazard.

United Kingdom

The Health and Safety at Work etc. Act 1974 requires employers to secure the health (including hearing), safety and welfare of workers at work. This includes providing a safe place of work, safe systems of work, and information and training.

The Management of Health and Safety at Work Regulations 1999 (as amended) require suitable and sufficient assessments of health and safety risks at work to be carried out, so that the necessary preventative and protective measures can be taken, including health surveillance.

The Control of Noise at Work Regulations 2005 place a duty on employers to reduce the risk to their workers’ health by controlling the noise they are exposed to while at work. According to these regulations, employers must protect their workers, whether temporary or permanent, from the harmful effects of workplace noise. Depending on the level of risk, they are required to:

  • take action to reduce noise exposure; and
  • provide workers with personal hearing protection.

Other duties under the Regulations include the need to:

  • make sure the legal limits on noise exposure are not exceeded
  • maintain equipment to control noise risks
  • provide workers with information, instruction and training, and
  • carry out health surveillance.

The Regulations set three action values for employers, depending on the levels of exposure to noise averaged over a working day or week and the maximum noise (peak sound pressure) to which workers are exposed in a working day:

  • lower exposure action values: daily or weekly exposure – 80dB, peak sound pressure – 135dB
  • upper exposure action values: daily or weekly exposure ¬– 85dB, peak sound pressure – 137dB
  • exposure limit values: daily or weekly exposure – 87dB (taking account of hearing protection), peak sound pressure – 140dB.

Recommended noise exposure levels

The occupational exposure limits for noise vary slightly from country to country but the generally accepted standard to minimise hearing risk is based on an exposure to 85 dB(A) for a maximum of eight hours per day. Noise levels above 140 dB are not considered safe for any period of time. The eight-hour-per-day exposure limit refers to the total amount of noise that an individual may be exposed to. This exposure may be from continuous or intermittent noise.

The following table provides exposure level criteria in various countries around the world.

Recommended noise exposure levels around the world

Courtesy of World Health Organization

Risk management programme

Occupational noise is a leading cause of noise-induced hearing loss, which is considered to be the 15th most serious health problem in the world. Developed nations are adopting innovative working practices and introducing stringent laws to control exposure to noise. However, the same cannot be said for all of the “developing” nations. As with any other hazard, it is essential to determine accurately the nature of the noise, identify affected individuals and implement controls to eliminate or reduce the risks associated with noise exposure.

The level and type of risk management programme will depend upon the scope and extent of the noise problem in the workplace. However, all the risks arising from noise should be considered. To prevent or minimise noise-related risks in the workplace, it’s a good idea to have a noise management programme. The programme should cover:

  • initial assessment
  • detailed noise assessment, if necessary
  • control measures
  • education and training
  • health surveillance.

All workers who are likely to be affected by noise should be identified. Attention should be paid not only to individuals who are exposed to noise in relatively fixed locations, but also to those who move between different jobs, while understanding their patterns of noise exposure. People who are not direct employees but who may be affected by the work, for example visitors or sub-contractors, should also be considered.

Initial assessment

Employers must protect the safety and health of their workers from all noise-related risks at work. The simple method to determine whether tasks or processes in the workplace expose workers to hazardous noise levels is by walkthrough survey, often referred to as preliminary assessment. A walkthrough survey is carried out in order to estimate workplace noise exposure levels. The basic rule of thumb that can be used to estimate the noise level in the workplace is:

  • if you have to shout to communicate with someone a couple of meters away and cannot hear clearly what they are saying to you, the noise level is likely to be 85 dB(A);
  • if you have to shout or have difficulty being understood by someone around one meter away, then the level of noise is around 90 dB(A).

Employers need to identify the scale of the noise problem before taking steps to control the risks within their workplace. Deciding whether they need to carry out a noise assessment should not be a complicated and time-consuming process. If satisfied that workers are not being exposed to harmful noise levels, no further action will be necessary except to ensure that noise exposure levels do not increase and to take action if they do. If in doubt, it’s best to check the actual noise levels by taking measurements. To do this, employers will need to have noise assessment done. Noise assessment will help to make an informed judgment on whether actions are necessary to prevent or control exposure to noise adequately.

Noise assessment

A risk assessment may not always need noise measurements to be carried out. For example, if a business operates only one machine with noise level above 85 dB(A) and the manufacturer has provided all the required information about the machine's noise levels, then a sufficient risk assessment can be made without carrying out any further measurements. However, complex situations may require detailed and accurate measurements by a competent person to determine the noise exposure levels.

The purpose of noise assessment is to establish whether or not workers are exposed to noise that is hazardous to their health. A noise assessment may be required:

  • if in doubt that noise levels are exceeding the safe exposure levels (exposure limits)
  • where high-level noise is being generated by various sources
  • to quantify the level of noise workers are exposed to
  • to assist in implementing the noise controls strategies
  • to determine the most suitable hearing protection devices.

Noise assessments are not a straightforward and easy step, especially when calculating the average exposures. This may require specialist equipment and fully-trained personnel to carry out the assessment. The degree and type of the assessment will depend on the scope and extent of the noise problem.

A good noise assessment:

  • identifies sources of noise and observes specific working practices
  • identifies the level, type and duration of noise exposure
  • identifies individuals who may be exposed to noise hazard
  • quantifies the level of noise individuals are exposed to
  • considers the effects of noise on workers whose health is at particular risk from exposure
  • considers indirect effects on workers’ health and safety such as masking of warning signals
  • identifies the necessary controls to eliminate or reduce the noise-related risks to the lowest reasonably practical levels
  • identifies workers who need to be provided with health surveillance.

The noise assessment should be carried out during a typical work day and must take into consideration all sources of noise in operation, the way the job is being performed and other related factors such as the surrounding environment. It must be carried out by a competent individual who thoroughly understands the objectives of the assessment, is adequately trained to use measurement instruments and able to interpret the results.

The assessment should be reviewed and updated regularly –especially if there is reason to suspect that the assessment is no longer valid or when there has been significant change in the work process or risk controls.

Exposure calculators and ready-reckoners

Noise exposure calculators are tools that can assist employers to work out the daily and weekly noise exposure levels to their workforce and to estimate the performance of any hearing protection that has been provided to them.

The following are some examples of noise exposure calculators, provided by the UK’s Health and Safety Executive:

The Health and Safety Executive’s noise exposure ready-reckoner tools provided below also assist employers to estimate daily or weekly noise exposure:

In order to use the ready-reckoner tools, employers will need to know the level as well as the duration of noise exposure which make up an individual’s working day.

Information and training for workers

Employers should provide their workers all the necessary information, instruction and training to help them understand all the possible noise-related health risks, and the precautions being undertaken to avoid such risks. These should include:

  • information on noise-related risks they’re facing in the workplace
  • measures taken to eliminate or reduce noise hazards
  • the findings of any risk assessment that has been carried out
  • information on the safe use of hearing protection that is provided
  • information on identifying signs and symptoms of hearing damage, and
  • the purpose of a health surveillance programme, if introduced.

The involvement of workers is very important as it helps to enhance their engagement and commitment to comply with procedures and improvements. By using workers’ knowledge and experience, employers can make sure that hazards are correctly spotted and workable solutions implemented.

Reporting mechanisms

Identifying hearing problems early is important. Employers need to make workers aware of the risk factors, what signs or symptoms to look for, and how to report them should they arise.