The Control of Noise at Work Regulations (2005) governs the requirements of employers in protecting their employees from damaging sound levels. They require employers to reduce risks wherever possible from exposure to noise at work. They also outline the requirements of any sound level meter used to obtain acoustic measurements.
The regulations require all employers to do the following:
- Assess the risks created by noise at work to all employees
- Take all possible action to reduce the noise exposure creates those risks
- Provide hearing protection to employees if the noise exposure cannot be reduced
- Ensure the legal limits on noise exposure are not exceeded
- Provide information and training to all employees on the dangers of noise exposure
- Where a risk has been identified, ensure health is monitored
These regulations have a few exceptions. Low-level noise that can cause a nuisance but is of no risk to hearing does not legally need to be combated. Likewise members of the public exposed to noise in their own-time or making a personal informed decision to be in the noisy environment do not legally need to be addressed.
What do you need to Measure?
Making estimations of the noise exposure of an individual at work requires the measurement of a couple of specific sound measurements. The first is the Equivalent Continuous Sound Level (Leq) weighted at Frequency Weighting ‘A’ (LAeq). This gives a representation of the total amount of noise a person is exposed to throughout the working day. You also need to obtain the Peak measurement of sound level ‘C’ Weighted (LCPeak) which represents the loudest sound to which the person is exposed.
We use the LAeq measurement to calculate the LEP’d (daily exposure) or LEP’w (weekly exposure) of an individual. Some sound meters will work this out automatically but generally speaking it requires a calculation provided in the Noise at Work Regulations (Schedule 1, Part 1, Paragraph 1) that requires the LAeq and the duration of which the LAeq is measured.
Once you know the LEP’d / LEP’w and LCPeak you can compare your results to the action levels provided in the regulations.
The Control of Noise at Work Regulations (2005) outline specific values for both the daily/weekly exposure and the peak sound pressure level at which action must be taken. An action level is fundamentally an exposure level at which employers are legally required to take different steps to reduce the risks on hearing.
Lower Exposure Action Values.
At this level the employer has to provide information and training and make hearing protection available.
- Daily LEP,d or weekly LEP,w exposure of 80dB
- Peak sound pressure (LCPeak) of 135 dB
Upper Exposure Action Values.
At this level the employer must take reasonable measures to reduce noise exposure such as trying to control the amount of noise the equipment produces. Hearing protection is mandatory while ever the sound levels are over this limit up until the sound levels have been controlled.
- Daily LEP,d or weekly LEP,w exposure of 85dB
- Peak sound pressure (LCPeak) of 137 dB
Finally, an exposure limit value exists that provide absolute limits that an employee cannot be exposed to. These are
- daily LEP,d or weekly LEP,w exposure of 87 dB
- peak sound pressure of (LCPeak) 140 dB.