Noise and vibration safety
Hearing loss caused by exposure to excessive noise at work continues to be a significant cause of occupational disease. People can suffer deafness, tinnitus or other forms of hearing damage. Vibration from hand-held power tools can also damage hands and fingers, causing painful disorders of the blood vessels, nerves and joints.
The risks from noise and vibration are easily controlled by:
- identifying potential sources of noise or vibration
- assessing how great the risk is by measuring noise levels, looking at exposure times, who is exposed and work activities
- putting into place control measures to reduce the risk
- monitoring how effective the control measure are by carrying out health surveillance
If you are responsible for work activities that generate noise or vibration, but are unsure whether staff are at risk, ask yourself the following questions:
- do staff have to raise their voice at work to have a normal conversation with someone who is 2m (6ft) away?
- do staff use noisy powered tools or machinery for over half an hour a day? Is your sector known to have noisy tasks, e.g. construction, woodworking, engineering, hospitality, waste and recycling and horticulture?
- do employees have muffled hearing at the end of the day, even if it is better by the next morning?
- is the noise intrusive, like a busy street or crowded restaurant, for most of the working day?
- do staff regularly use powered hand-held tools such as sanders, grinders, powered mowers and disc cutters?
If you answered 'yes' to any of the questions above staff may be at increased risk from hearing damage and the effects of vibration. If you need further advice, please contact Health and Safety who can advise you on measurement of noise exposure and vibration risk assessment.
Risk assessment
A risk assessment will enable you to make a valid decision about whether people are at risk from exposure to noise or vibration and what action you may need to take to prevent or adequately control that exposure. To do that you must estimate the noise and vibration exposure levels taking into account the factors related to the risk. This will identify what steps you will need to take to control the risk and whether health surveillance is needed.
It might be possible to estimate noise and vibration exposure levels or you may need to get support to carry out a detailed assessment. Below is the basic information you need to estimate noise and vibration exposure.
Noise
- How loud is the noise, including peak noise? Noise levels can be obtained by taking measurements in the workplace, using noise information from other workplaces to yours and data from suppliers of machinery. Where you find sound pressure levels greater than 80 dBA should be assessed further. This is your noise hazard information and can be recorded on the risk assessment.
- How long are people exposed to the noise? Think about what work is done or likely to be done. How is the work carried out day to day and how will it vary? What is the frequency of exposure? This is your noise hazardous event and can be recorded on the risk assessment.
- Who is exposed to noise directly or indirectly? Do you have people who are at increased risk due to existing health conditions, impaired hearing or hearing damage? You record who is at risk assessment on the risk assessment.
The noise level and length of exposure can then be used to calculate a person’s daily or weekly exposure. You need to compare your estimated noise exposure with the Exposure action values to know what action you need take. There are ‘lower’ and ‘upper’ Exposure action values and an Exposure limit value that cannot be exceeded. For example, if you exceed the upper Exposure action value, at risk people will need health surveillance, wear hearing protection and the noise reduced so far as is reasonably practicable
Vibration
- How much vibration is generated? Vibration levels can be obtained from vibration information from other workplaces to yours and data from suppliers of machinery. Machinery that has hand arm vibration levels greater than 2.5m/s2 should be assessed further. For whole body vibration, machinery that has vibration levels greater than 0.5m/s2 should be assessed further. This is your vibration hazard information and can be recorded on the risk assessment.
- How long are people exposed to the vibration? Think about what work is done or likely to be done. Is it hand arm vibration or whole body vibration? How is the work carried out day to day and how it varies? What is the frequency of exposure? This is your vibration hazardous event and can be recorded on the risk assessment.
- Who is a risk from the vibration? Do you have people who are at increased risk due to existing health conditions? You record who is at risk assessment on the risk assessment.
The vibration level and length of exposure can then be used to calculate a person’s daily exposure. You need to compare your estimated vibration exposure with the Exposure action value for hand arm vibration and whole body vibration to know what action you need take. There are also corresponding Exposure limit values that cannot be exceeded. For example, if you exceed the Exposure action value, at risk people will need health surveillance and the vibration risk reduced so far as is reasonably practicable.
Health surveillance
Health surveillance will be required in the following circumstances:
- Employees are regularly exposed to noise above the upper exposure action levels:
- Daily or weekly exposure of 85dB
- Peak sound pressure of 137dB
- Employees who may be at increased risk due to an existing hearing/ear condition health surveillance will be required.
- Employees who are regularly exposed to vibration above the action value of 2.5m/s2 (over an 8 hour period) or who have an existing diagnosis of HAVS (even when exposed below the action value).
Your Noise / HAVS assessment will identify whether health surveillance is required. Find out more about the types of health surveillance required and the purpose of health surveillance.
