Health surveillance and audiometry under the Noise at Work Regulations

Mary Kinoulty reviews the relevant requirements of the new Regulations.

Key points The 2005 Regulations place new duties on employers to carry out audiometry on a wider range of activities and work areas than those previously in place. Employers need to be provided with sufficient information to allow them to investigate higher-than-normal rates of hearing loss.

New cases of noise-induced hearing loss continue to be identified, with the highest incidence of those qualifying for benefits being in extraction and water supply, manufacturing and construction.

The HSE's survey "Self-reported work-related illness in 2004/05"¹ estimates that 74,000 of those who have ever been employed in Great Britain were suffering from work-related hearing problems in that year.

The Control of Noise at Work Regulations 2005 aim to protect against these entirely preventable "bloodless injuries".

One of the innovations of the 2005 legislation is a specific regulation covering health surveillance/audiometry (where previously there was only an implied duty in the official guidance).

In other respects, the key statutory duties of the 2005 Regulations address the same issues as the 1989 Regulations, which they replaced, namely: risk assessment; exposure control; hearing protection (ie protectors); use of equipment (including protectors); and information, instruction and training (see box 1 and table 1).

Whereas the previous implied duty to carry out audiometry applied when the then second action level (90dB(A)) was likely to be exceeded, table 1 shows that that threshold has been lowered by 5dB(A) under the new Regulations.

Employers therefore need to consider a wider range of activities and work areas, and a larger number of employees as candidates for risk assessment and health surveillance.

In respect of audiometry, reg. 9 requires employers to:

• place under suitable health surveillance employees whose health is at risk from noise exposure;
• include a hearing test in the health surveillance;
• keep a health record;
• give employees and enforcers access to health records;
• advise employees and refer them appropriately where damage is found that is likely to be due to noise; and
• allow at-risk employees to attend health surveillance during working time and at the employer's expense.

Health surveillance

The key requirement of reg. 9 is for employers to have systematic, regular and appropriate procedures in place to detect early signs of noise-induced hearing loss and to act on the results. The aim is both to protect the hearing of exposed employees and to monitor the effectiveness of control measures.

The HSE's official guidance² provides more detailed information and key aspects are addressed below.

Selecting personnel: The guidance indicates that the basic threshold for health surveillance is regular exposure above the upper exposure action value (85dB(A)). Where exposures are between the upper and lower exposure action values, it is necessary to carry out health surveillance only for those employees identified as being sensitive to noise-induced hearing loss (eg those with a past medical history of hearing difficulty or with a previous abnormal audiogram).

Audiometry programme: Where a system of audiometric testing is advised, an individual should be appointed to oversee the programme to ensure quality of testing, record-keeping and onward referral. As with all health surveillance programmes, it is important for employees to understand what is involved (ie an ear examination, a questionnaire and audiometry) and to be aware of the implications of the programme (eg the possibility of being found to be unfit for their job). Prior to audiometry, the ear should be examined to ensure that the canal is not blocked or the ear drum damaged. It is also advisable to limit noise exposure so that the effects of temporary threshold shift are minimised.

The programme should commence with a baseline assessment for all employees who are identified as requiring health surveillance, and a pre-employment assessment for new employees. The guidance suggests audiometry should be carried out annually for the first two years and every three years thereafter, or more frequently if problems are identified.

Audiogram evaluation: The HSE has revised the categorisation scheme (see table 2), replacing that previously endorsed in HSE guidance note MS26. The categorisations can be calculated by following the guidance and using the revised warning and referral levels, which are listed separately for males and females in various age bands. Interpretation of the audiogram may highlight problems other than noise-induced hearing loss. At this point, it is important to inform the employee concerned of the result and to discuss the potential impact on their job role. Where significant noise-induced hearing loss is identified, it will be necessary to discuss the job in detail and to ensure that any personal hearing protection provided is suitable and is being worn correctly for the whole of the exposure period. Where the employee is operating in a safety-critical area or needs to communicate easily or respond to auditory warning signals, an "on-the-job test" may need to be carried out to allow a decision to be made on fitness for work.

Health record: A health record should be kept for all employees undergoing health surveillance and should include an identification number, a history of noise exposure and the outcomes of previous health surveillance in terms of fitness for work. Health records should not include personal information and should be kept for the period of employment at least - possibly longer, given the potential for litigation in relation to noise-induced hearing loss. The health record should be accessible to the individual employee and also to the enforcing authority.

Effectiveness of the hearing conservation programme: As with all health surveillance programmes, it is vital to act on the results obtained. Individual results should be provided to the employer in the form of a fitness-for-work certificate. Further analysis of the audiometric data is suggested in the guidance and can provide useful information to the employer about the overall effectiveness of the hearing conservation programme. Many computerised audiometer systems will provide statistical analysis (for example, by work area), and this data can be fed back in anonymised group form. This analysis will allow for the identification of areas where there is a higher-than-average rate of hearing loss and for investigation and remedial action.

References

1. HSE (2006). "Self-reported work-related illness in 2004/05: Results from the Labour Force Survey" (PDF format, 2.71MB) (on HSE website).

2. "Controlling noise at work. Guidance on the Control of Noise at Work Regulations 2005", L108, ISBN 0 7176 6164 4 HSE Books.

Dr Mary Kinoulty is a specialist occupational physician with Grosvenor Health. She previously worked for the Health and Safety Executive.

Box 1: key duties of the control of noise at work regulations 2005 Assessing the risk (reg. 5) The noise-risk assessment needs to identify where there may be a risk and who may be exposed, include an estimate of exposure and identify the actions required to comply with the law. An exposure calculator for determining the cumulative exposures associated with different tasks and tools is available on the HSE website (www.hse.gov.uk/noise). Taking action to eliminate or control noise exposure (reg. 6) Wherever there is noise exposure, employers are required to consider alternative processes, equipment and/or working methods to reduce exposure levels or exposure time. Providing personal hearing protection (PHP) (reg. 7) Employers are required to provide PHP for employees exposed to the upper exposure action value, or above, and to offer it to those exposed to between the lower and upper exposure action values. Maintenance and use of equipment (reg. 8) Employers are required to ensure that noise control equipment and PHP is used appropriately. Health surveillance (reg. 9) This should be provided to all employees "identified as at risk" (see "Health surveillance" in main article). Information, instruction and training (reg. 10) Exposed employees need to be made aware of the health risks, the actions being taken by the employer to control noise and the need to comply with health surveillance requirements and the wearing of PHP.

Table 1: Key actions required by employers at particular noise levels

Exposure level	Actions required
At lower and upper exposure action value and exposure limit values	Carry out a risk assessment of noise to which workers are exposed.
At or above lower exposure action value (80dB(A) daily/weekly, 135dB peak)	Provide personal hearing protection to individuals on request. Provide health surveillance for individuals identified as particularly sensitive to noise. Provide information, instruction and training.
At or above upper exposure action value (85dB(A) daily/weekly, 137dB peak)	Reduce noise to as low a level as practicable, based on the general principles of prevention. Provide personal hearing protection for all those exposed. Designate the area as a hearing protection zone. Provide health surveillance. Provide information, instruction and training.
At or above the exposure limit values (87dB(A) daily/weekly, 140dB peak)	Employees should not be exposed above these values. However, if an exposure limit value is exceeded: Reduce exposure to below the exposure limit value. Identify the reason for that exposure limit value being exceeded. Modify the organisational and technical measures taken to prevent it being exceeded again.

Table 2: Revised HSE audiogram categorisation scheme

Category	Calculation	Action
Acceptable hearing ability Hearing within normal limits.	Sum of hearing levels at 1kHz, 2kHz, 3kHz, 4kHz, and 6kHz.	None
Mild hearing impairment Hearing within 20th percentile (ie hearing level normally experienced by one person in five). May indicate developing noise-induced hearing loss.	Sum of hearing at levels 1kHz, 2kHz, 3kHz, 4kHz and 6kHz. Compare value with figure given for appropriate age band and gender.	Warning
Poor hearing Hearing within fifth percentile (ie hearing level normally experienced by one person in 20). Suggests significant noise-induced hearing loss.	Sum of hearing levels at 1kHz, 2kHz, 3kHz, 4kHz, and 6kHz. Compare value with figure given for appropriate age band and gender.	Referral
Rapid hearing loss Reduction in hearing level of 30dB or more within three years or less. Such a change would be caused by noise exposure or disease.	Sum of hearing levels at 3kHz, 4kHz and 6kHz.	Referral