Control of Noise at Work Explained

Noise damages hearing by fatiguing the hair cells in the cochlear, which forms part of the inner ear. The damage appears initially as a temporary hearing loss, usually accompanied by tinnitus (ringing in the ears) following exposure but can then become a permanent condition. The industrial revolution triggered high levels of noise exposure for prolonged periods to the lives of working people on a regular basis, and this was originally thought of as inevitable for those working in noisy industries. One study in 1927 suggested that at least 27% of cotton workers in Lancashire suffered some degree of deafness, which led to the term ‘cloth ears’ which describes someone who is unable to hear properly. However, this information probably gives a skewed picture as the effects of noise on hearing tend to build up over time and it is normally only after some years of exposure that the effects can become noticeable. Unfortunately, by this point, the effects are totally irreversible.

Noise and the Worker

In 1963 the (then) Ministry of Labour published ‘Noise and the Worker ’ which noted, quite correctly, that the effects of noise on hearing depends, not only on the level of exposure, but also the duration, and that it is therefore necessary not only to measure the noise, but to assess the amount of exposure to it during a normal working day or working life. At that time they stated that knowledge was too limited for it to be possible to say with certainty what amount of exposure was safe but that ‘it is generally agreed that if workers are exposed for eight hours a day, five days a weeks, to a continuous, steady noise of 85 decibels or more in any octave band, in the speech range of frequency (500 to 4,000 cycles per second), it is desirable to introduce a programme of noise reduction or hearing conservation’.

Reducing the Exposure of Employed Persons to Noise

By 1972, the (then) Department of Employment ‘Code of Practice for Reducing the Exposure of Employed Persons to Noise’ introduced the concept of LAeq (‘A’-weighted equivalent continuous sound level) and a limit of 90 dB LAeq over an 8-hour working day (LAeq,8h). The LAeq is the energy average of the noise received over a given time period. It is equivalent, in energy terms, to a steady noise at that level operating over the same length of time. The ‘A’ weighting means it is corrected for the frequency response of the human ear. Use of the LAeq concept means that if the exposure time is halved, the noise level can be doubled, and vice versa. By way of illustration, a noise level of 90 dBA for 8 hours has the same LAeq,8h value as 93 dBA for 4 hours or 87 dBA for 16 hours. It also contained a limit on instantaneous levels of noise to the effect that maximum noise level should not exceed 135 dBA measured using ‘fast’ response. A useful explanation of some of these concepts can be found here.

The 1989 Noise at Work Regulations

The 1972 Code of Practice appears to have been largely ignored by employers until the 1986 EU Noise at Work Directive resulted in the 1989 Noise at Work Regulations becoming law in the UK. This used the same concepts as the 1972 document but used the term ‘daily personal noise exposure’ (LEP,d) to describe the daily noise dose (equivalent to the LAeq,8h). It also introduced the First and Second Action Levels (corresponding to LEP,d values of 85 and 90 dBA respectively) and a Peak Action Level of 140 dB measured using a sound level meter set to ‘Peak’ response. An assessment was required by Law where there was a likelihood of exposure above the First or Peak Action Level. For employees that could be exposed above the First Action Level, their employer had a duty to provide information on noise exposure and the potential risk of deafness – they were also obliged to and to provide hearing protection equipment on request. For employees exposed above the Second Action or Peak level, the employer had a duty to ensure that hearing protection equipment was worn. Employers also had a more general duty to reduce the level of noise as far as ‘reasonably practicable’ other than through the provision of personal hearing protectors. Certain exemptions from these regulations were provided for those working in environments like on ships or working as aircraft crew and within the national security forces. A full guide to these regulations can be found at Reducing Noise at Work – Guidance on the Noise at Work Regulations 1989.


The 2005 Control of Noise at Work Regulations

The current noise at work guidance is the 2005 Control of Noise at Work Regulations which must be complied with by all employers. It should be noted that the regulations apply across the board to all employers including those in the manufacturing, construction, transport and leisure industries, where the latter can include high levels of noise from motor sports and amplified music such as in night clubs or performance venues. The regulations apply equally to employers and the self-employed, who are treated as though they are both employer and employee.

In this document, the previous First and Second Action Levels have become the Lower and Upper Exposure Action Values (both of which include the assessment of the noise dose as well as instantaneous noise level) and there are new concepts of an Exposure Limit Value and weekly personal noise exposure (LEP,w).

Regulation 4 – Action Levels and Exposure Limit Values

Regulation 4 defines the action values and exposure limit values as follows:

The Lower Exposure Action Value is -

(a) a daily or weekly personal noise exposure (LEP,d or LEP,w) of 80 dB (A-weighted); and (b) a peak sound pressure of 135 dB (C-weighted).

The Upper Exposure Action Value is -

(a) a daily or weekly personal noise exposure (LEP,d or LEP,w) of 85 dB (A-weighted); and (b) a peak sound pressure of 137 dB (C-weighted).

The Exposure Limit Value is -

(a) a daily or weekly personal noise exposure (LEP,d or LEP,w) of 87 dB (A-weighted); and (b) a peak sound pressure of 140 dB (C-weighted).

It may be noted that the action values for noise dose are reduced by 5 dB compared to the 1989 regulations and that action is required for instantaneous noise levels at a level 5 dB lower than previously, albeit with a ‘C’ weighted Peak level (rather than ‘Linear’). It is stated that, ‘where the exposure of an employee to noise varies markedly from day to day, an employer may use weekly personal noise exposure (LEP,w) in place of daily personal noise exposure (LEP,d) for the purpose of compliance with these Regulations’. Compliance with the Limit Values can take account of the provision of hearing protection, but not the Action Values.

Regulation 5 – Assessment of Risk to Hearing

Regulation 5 states that ‘an employer who carries out work which is liable to expose any employees to noise at or above a lower exposure action value shall make a suitable and sufficient assessment of the risk from that noise to the health and safety of those employees’ and that ‘the risk assessment shall identify the measures which need to be taken to meet the requirements of these Regulations

Regulation 6 – Reduction of Risk

Regulation 6 requires the employer to ensure that ‘risk from the exposure of his employees to noise is either eliminated at source or, where this is not reasonably practicable, reduced to as low a level as is reasonably practicable’ and that ‘if any employee is likely to be exposed to noise at or above an upper exposure action value, the employer shall reduce exposure to as low a level as is reasonably practicable by establishing and implementing a programme of organisational and technical measures, excluding the provision of personal hearing protectors, which is appropriate to the activity’. It also requires the employer to ‘ensure that his employees are not exposed to noise above an exposure limit value’ which can be done using hearing protection provided that noise above the Upper Action Level has already been reduced as far as possible (see Regulation 7).

Regulation 7 – Provision of Hearing Protection

Regulation 7 requires that, without prejudice to the provisions of regulation 6, ‘an employer who carries out work which is likely to expose any employees to noise at or above a lower exposure action value shall make personal hearing protectors available upon request to any employee who is so exposed’ and that ‘if an employer is unable by other means to reduce the levels of noise to which an employee is likely to be exposed to below an upper exposure action value, he shall provide personal hearing protectors to any employee who is so exposed’.

Regulation 7 furthermore requires that ‘if in any area of the workplace under the control of the employer an employee is likely to be exposed to noise at or above an upper exposure action value for any reason the employer shall ensure that—

(a) the area is designated a Hearing Protection Zone;

(b) the area is demarcated and identified by means of the sign specified for the purpose of indicating that ear protection must be worn…..; and

(c) access to the area is restricted where this is practicable and the risk from exposure justifies it, and shall ensure so far as is reasonably practicable that no employee enters that area unless that employee is wearing personal hearing protectors’.

Hearing protection, provided as required by the above, is required to be sufficient to eliminate the risk to hearing or to reduce the risk to as low a level as is reasonably practicable.

Assessment of Noise Exposure at Work in Line with the Control of Noise at Work Regulations

To be compliant with the 2005 Control of Noise at Work Regulations, employers first need to determine whether there is any possibility of noise exposure at or above the lower exposure action value. This may be a difficult call to make but it is recommended that if there is exposure to ‘noisy’ machinery on a daily, or even intermittent basis, that a full noise risk assessment should be carried out. Hayes McKenzie can provide preliminary advice, as to whether such a noise assessment is required.

Hayes McKenzie will undertake an in-depth assessment which will include a noise survey of the locations where workers are exposed, and our specialist experts will calculate personal noise exposure for all affected employees.

Sometimes the only way to assess the daily or weekly noise dose is via the use of personal dose meters which an employee can wear throughout the day or week to measure the LEP,d or LEP,w. These are not always ideal owing to the lack of control, by the noise assessor, over exactly what is being measured, but may be the only solution where noise exposure is highly variable or intermittent and unpredictable.

Hayes McKenzie can provide advice on the reduction of noise exposure required, through noise reduction at the source (or otherwise). They are also able to advise on suitable hearing protection as necessary.

It should be noted that health surveillance (including hearing tests) are required where assessment shows there is a high noise risk to (hearing) health.

As with the previous regulations, certain exemptions are available but only if a certificate is applied for and provided by the HSE.

For a full and proper understanding it is recommended that reference is made to the 2005 Control of Noise at Work Regulations themselves. Other useful guidance published by the HSE can be found in the HSE document Noise at Work: A brief guide to controlling the risks and the associated document Controlling Noise at Work. There is also a useful HSE guide to control of noise at work in music and entertainment and an associated ‘MythBusters’ document.

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Date Posted

08 Nov 2018

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