The Noise At Work Action Levels And Legal Limits

Do you often long for a bit of peace and quiet? Time away from the stress and strain of work? A break from the hustle and bustle? Some tranquillity?

You're not alone. We all need a bit of silence sometimes. It can help us concentrate and focus. Or even help us stay calm and relaxed.

If you are exposed to noise at work, it can be distracting. A faulty buzzing light or some temporary building works at your office, for example, can be a real nuisance.

Too much noise can be more than a nuisance. High levels of noise can cause permanent and disabling hearing loss. This is not a small problem either. The HSE reports that in the UK alone some 17,000 people suffer deafness, ringing in the ears or other ear conditions caused by excessive noise at work.

If you feel like noise at work is something you want to get away from, then something is wrong.

We are at work usually around 8 hours a day, and while your work might not always be enjoyable, it shouldn't be uncomfortable or harmful.

But what if you are a builder, or if you work in a factory or warehouse, and you are exposed to noisy work every day?

Well, some workplaces are noisier than others. But, even if you work in a noisy industry, noise at work must be controlled. It's the law.

Employers have a responsibility to protect the health and safety of their workforce. And this duty extends to noise exposure.

Noise is such a big problem, there is a specific set of regulations that apply. The Control of Noise at Work Regulations. These regulations cover duties regarding managing noise at work and specify legal limits regarding noise levels.

Exposure Action Values

The first limits to be aware of when it comes to noise, are the exposure action values.

Action values are not hard limits. But these are the levels of noise exposure at and above which you need to take certain actions. So, action levels can be exceeded, but only in a controlled way.

4.—(1) The lower exposure action values are—

1. a daily or weekly personal noise exposure of 80 dB (A-weighted); and
2. a peak sound pressure of 135 dB (C-weighted). (2) The upper exposure action values are—
3. a)
4. a daily or weekly personal noise exposure of 85 dB (A-weighted); and
5. a peak sound pressure of 137 dB (C-weighted).

You'll notice some of the action and limit values are A-weighted, and some are C-weighted. These are just slightly different ways of measuring noise levels, which can be set on noise-measuring devices.

A-weighted is an approximation of how the human ear perceives the noise and is the average noise level. C-weighting is more commonly used for measuring peak measurements (impact or explosive noise levels).

So if the average noise level is above 80 dB(A) (average) or 135 dB(C) (peak) then action needs to be taken.

If people are exposed to noise at or above the lower action values, then a risk assessment must be carried out. This should assess the level, type and duration of exposure, and the measures needed to reduce or control that exposure.

And if the average noise level is above 85 dB(A) (average) or 137 dB(C) (peak) then action needs to be taken to reduce the noise, or reduce the exposure with hearing protection and hearing protection zones.

The upper exposure action values might not seem that much higher than the lower exposure action values, but noise doubles around every 3 dB, so in practice, the noise is much louder from 80 dB (busy traffic) to 85 dB (drilling).

Exposure Limit Values

(3) The exposure limit values are—

1. a daily or weekly personal noise exposure of 87 dB (A-weighted); and
2. a peak sound pressure of 140 dB (C-weighted).

Exposure limit values are just that, a limit. They are the levels of noise above which an employee may not be exposed.

That's not a limit on the noise in the workplace, but it is a limit on the level of noise workers get exposed to after you have put controls in place.

The exposure limit values that must not be exceeded. If these limits are exceeded employers need to take action. This includes reducing exposure below the limit, identifying why it was exceeded, and making changes to prevent it from being exceeded again.

Measuring Noise

If you work in a noisy workplace, you probably know about it. As a general guide, if you stand 2 meters away from a colleague, and you struggle to hear through the noise without shouting, then action should be taken.

If you need to shout to be heard by someone 1m away, noise levels could be 90dB or more.

Before hearing loss occurs, noise exposure can have a negative effect on concentration and cause irritability which can lead to mistakes, accidents and poor productivity.

These are all early warning signs of a noise problem at work.

Of course, the only way to know if noise is a problem is to measure it. How else can you know if you are within the noise exposure action values or limit values?

You can use noise reading equipment to establish the level of noise exposure and assess the appropriate action required.

Alternatively, equipment manufacturers will usually do noise measurements, and provide details of the expected noise output within the user manual and equipment specifications. However, the noise levels can vary depending on the type of use and environment, and don't forget about the combined noise of all the equipment and sounds within your workplace.

Reducing Noise Levels

Action should start with trying to reduce noise levels, through changing equipment where possible to those with lower noise output, or perhaps moving it further away from the work area if appropriate to do so.

Having your equipment serviced regularly can also help to prevent noise levels from increasing. Blunt or faulty tools often create more noise.

Another option to reduce noise levels in the workplace could be installing an acoustic enclosure around the equipment, to minimise the spread of noise output, and contain the noise within a controlled area.

Actions that can be taken to eliminate or reduce noise at work include:

• Changing processes and working methods
• Consider noise levels in equipment selection
• Maintain equipment and machinery
• Eliminating, reducing, damping or cushioning impacts
• Attaching silencers
• Provide periods of relief
• Install noise enclosures
• Acoustic screens and barriers
• Increasing the distance between people and noise
• Limit duration of exposure

Hearing Protection

PPE is your last line of defence, and where noise levels have been reduced as much as possible but are still above the action levels, hearing protection should be provided.

Where noise levels are at or above the lower action values - 80 dB(A) or 135 dB(C) - hearing protection must be provided on request.

Where levels are at or above the upper limits - 85 dB(A) or 137 dB(C) - hearing protection must be worn at all times. Ears are sensitive, and there is a real risk of hearing loss at and above these levels.

Don't just rely on hearing protection. As a personal protective measure, it only protects the wearer.

It is important to be aware that other controls will be required, in addition to hearing protection, if noise levels are above the upper action values. Hearing protection should not be the only control.

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