Your Work and Your Health

Noise


 


Noise - the employers' perspective


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Frequently Asked Questions

What is noise?

In work situations noise is normally defined as unwanted sound - an undesirable by-product of our normal day-to-day activities, for example aircraft, traffic, and machinery noise. It can also be an intended sound such as loud music.  Whether wanted or unwanted there is a risk that your hearing may be damaged when you are exposed to noise, which may result in temporary and/or permanent deafness.


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Do I need to understand noise?

You do not need to have an in-depth understanding of noise in order to be able to protect your workers from the potentially damaging effects of noise. However it would be useful for you to know some of the common terms used for describing noise in the workplace.

Mechanical movements from for example fans, power tools and vehicles, set up fluctuations in the air pressure. These travel as sound waves through the air, spreading out just like ripples in water when a stone is dropped into a still pond. The frequency of the sound is the number of fluctuations per second, expressed as hertz (Hz). The frequency of a sound produces its distinctive tone; the rumble of distant thunder has a low frequency, while a whistle has a high frequency.

Sound is measured in decibels (dB). The ear does not hear all frequencies as equally loud. It is most sensitive to sounds between 2 kHz and 5 kHz, and less sensitive at higher and lower frequencies. Noise measurements are often A-weighted to reflect how the ear responds to noise. They are expressed in units of dBA. Some typical dBA levels are given below:

  • normal conversation 65 dBA
  • lathe 80 dBA
  • train passing 100 m away 85 dBA
  • road breaker 95 dBA
  • grinding 110 dBA


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Why should I be concerned about Noise?

As an employer, you have duties under the Control of Noise at Work Regulations 2005 to manage the risk to your workers' hearing if they are exposed to noise at work because it could damage their hearing.

Initial exposure to high levels of noise may result in temporary deafness - ie temporary threshold shift. Although hearing can recover within a few hours it is a sign that continued exposure to noise at this level could cause permanent hearing damage. Unfortunately, by the time that such hearing loss is apparent, the damage to hearing is generally considerable and can't be cured.

Permanent hearing damage can also occur immediately following exposure to sudden, extremely high explosive noises, for example from guns or cartridge-operated tools. Workers could also suffer from tinnitus following exposure to these sudden loud noises.


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How will I know if noise is harmful in my workplace?

Certain types of work are known to be associated with high levels of noise, for example engineering workshops, sawmills, foundries, bottling plants, clubs, textile mills, farming, forestry, or construction. Your workers' hearing could also be at risk if they are involved in these types of work.

Your workers' hearing could be at risk if:

  • they have to shout to be clearly heard by someone 2 m away;
  • their ears are still ringing after leaving work;
  • they use equipment that causes loud explosive noises such as guns or cartridge-operated tools.


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Do I have a legal duty to protect my workers' hearing?

Yes! You have a legal duty under the Control of Noise at Work Regulations 2005 to assess and where required reduce the risk of injury to the hearing of your workers. You therefore need to be aware of the requirements of these regulations.

The Health and Safety Executive (HSE) has produced guidance that will help you understand your duties under the noise regulations. It includes information on:

  • the effects of exposure to noise;
  • your legal duties to protect your workers' hearing;
  • how to assess and control the noise;
  • how to choose quieter equipment and machinery;
  • different methods of hearing protection;
  • health surveillance (hearing checks).

This guidance is freely available at http://www.hse.gov.uk/pubns/indg362.pdf. You can also obtain a free copy by calling the HSE Infoline on 08701 545 500.


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When do I have to protect my workers' hearing?

Your duties to assess and control noise exposures under the noise regulations apply when your workers' noise exposure exceeds certain action values.  Preference should be given to controls that reduce the noise level or duration of the noise exposure rather than hearing protection.  Hearing protection is always a last resort or a temporary measure until other controls are implemented.

  • simple actions to assess and control noise and to inform staff are required at and above the lower action values, corresponding to a daily personal noise exposure of 80dBA, or a peak sound pressure of 135dBC; 
  • additional actions such as a control action plan and possibly health surveillance are required at and above the upper exposure action values corresponding to a daily personal noise exposure of 85dBA, or a peak sound pressure of 137dBC
  • a limit value corresponding to a daily personal noise exposure of 87dBA, or 140dBC peak sound pressure must not be exceeded. 

Note that the limit value takes into account the attenuation provided by hearing protection.  The lower and upper action values correspond to the exposureDo I need to provide health surveillance for my workers?  at the unprotected ear.
Action values and limit values are given as daily personal noise exposure, shortened to LEP,d.  LEP,d iscalculated using the level of noise and the amount of time your workers are exposed to it. LEP,d values take into account your workers' exposures over the whole working day or shift.  Where noise exposure varies markedly and predictably over the week, weekly averaging of exposure can also be used.

Action values and limit values are also given as the maximum C-weighted instantaneous peak sound pressure reached by a single, short, sharp noise, for example the noise from power press, drop forge, firing of explosives or firearms.
If your employees are exposured over the action values given in the Control of Noise at Work Regulations  you can find guidance on appropriate noise controls, and protection measures for employees in  "Controlling Noise at Work: Guidance on the Control of Noise at Work Regulations 2005 - L108" which is available from HSE Books and good booksellers.  Representatives of the UK entertainment sector have also produced additional guidance for music and entertainment called Sound Advice - HSG260 also available from HSE Books.

Further information is also available from www.hse.gov.uk/noise/index.htm.  You will find calculators to work out weekly and daily noise exposures using noise levels and exposure durations, and for determining the suitability of hearing protection.  You will also find the Sound Advice guidance for music and entertainment.

If you do not have immediate access to the noise levels your workers are exposed to, you could contact tool and machinery manufacturers and suppliers. They may be able to give you reliable information on the noise levels that could be produced by their products, which could be used to estimate your workers' likely noise exposure. However in due course you would need to verify your estimate since using manufacturer's data for assessment purposes may underestimate or overestimate your workers' daily personal noise exposure.


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Do I need to provide training for my workers?

If your workers are exposed to noise above any of the action levels, you need to provide information, instruction and training on what measures you have put in place to control the risk of damage to their hearing. This should include information on the level of risk to your workers' hearing as identified by the noise assessment, what measures you have put in place to control that risk, training to all the workers on the control measures including the use and maintenance of hearing protection, health surveillance, and the duties your workers have under the noise regulations.

If you do not have the skills or knowledge, or access to them from people within your workforce, to implement the requirements of the noise regulations you will need to go outside the company for advice. In the longer term you may want to organise some training for yourself or your workers, so that you have access to the necessary skills and knowledge in-house.


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Do I need to provide health surveillance for my workers?

If your risk assessment indicates a risk to workers’ health – either because you know an individual is particularly sensitive, or they are regularly exposed above the upper exposure action value, you need to provide health surveillance. This consists of regular hearing checks (audiometric testing) to identify early signs and symptoms of work-related ill health that allows action to be taken to prevent its progression.

This will enable you to determine if your hearing protection programme or your noise control programme is effective, and for individuals to receive advice on their own hearing and take action to protect their hearing.


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Where can I get help and advice?

There are many sources of help and advice available to you covering noise assessments, calculating noise exposure and noise control. Examples of where this advice can be found include HSE, trade associations and trade unions. If you have access to the internet, HSE has a webpage for noise at http://www.hse.gov.uk/noise. You can also obtain information on noise by calling the HSE Infoline on 08701 545 500.

A variety of training courses are available to help you gain the necessary skills and knowledge to carry out your duties under the noise regulations. Alternatively you use consultants who already have the necessary training and experience to help you carry out your legal duties. Contact details for training courses and consultants are given below:

Institute of Acoustics
77A St Peter's Street, St Albans, Hertfordshire, AL1 3BN
Tel: 01727 848195
Email: ioa@ioa.org.uk
Web: www.ioa.org.uk

National Examination Board in Occupational Safety and Health (NEBOSH)
Dominus Way, Meridian Business Park, Leicester, LE19 1QW
Tel: 0116 263 4700
Email: info@nebosh.org.uk
Web: www.nebosh.org.uk

British Occupational Hygiene Society (BOHS)
Faculty of Occupational Hygiene, Suite 2, Georgian House, Great Northern Road, Derby, DE1 1LT
Tel: 01332 298101
Email: admin@bohs.org
Web: www.bohs.org

Association of Noise Consultants
6 Trap Road, Guilden Morden, Royston, Hertfordshire, SG8 0JE
Tel: 01763 852958
Email: mail@association-of-noise-consultants.co.uk
Web: www.association-of-noise-consultants.co.uk


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This site is supported by the Healthy Work Matters Group