What Do 80, 85 and 87 dB Mean at Work?
Workplace noise is measured in decibels, but the number alone does not tell the whole story. How long someone is exposed, the type of noise and the effectiveness of existing controls all matter.
In the UK, workplace noise guidance commonly refers to lower and upper exposure action values and an exposure limit value. These figures are a starting point for risk assessment, not a substitute for a competent noise survey or current official guidance.
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Key workplace noise values
| Value | Daily or weekly exposure | Peak sound pressure | What it means |
|---|---|---|---|
| Lower exposure action value | 80 dB(A) | 135 dB(C) | Noise should be assessed and hearing protection made available where needed, with suitable information and training. |
| Upper exposure action value | 85 dB(A) | 137 dB(C) | Employers should reduce exposure as far as reasonably practicable, provide suitable protection and manage hearing-protection zones where required. |
| Exposure limit value | 87 dB(A) | 140 dB(C) | The limit takes account of hearing protection at the wearer. It should not be exceeded. |
These values and employer duties should always be checked against current UK requirements and the conditions of the specific workplace.
What do dB(A) and dB(C) mean?
dB(A) is an A-weighted measurement designed to reflect the sensitivity of human hearing across different frequencies. It is commonly used when considering longer-term daily or weekly noise exposure.
dB(C) is a C-weighted measurement that includes more low-frequency sound. It is commonly used for peak or sudden noise, such as impacts, bangs and explosive sound.
Noise control should come before PPE
Hearing protection is important, but it should not be the only control. A sensible approach starts by considering whether the noise can be removed or reduced at source:
- Eliminate or substitute the noise where the process or equipment can be changed.
- Use engineering controls such as enclosures, barriers, isolation, damping or quieter machinery.
- Manage exposure through maintenance, working-time controls, quieter areas and suitable hearing-protection zones.
- Use hearing protection where a remaining risk requires it, with training, fit checks and supervision.
Why the highest-rated hearing protection is not always best
Choosing the biggest available rating can make communication, alarms, reversing signals and other important sounds harder to hear. It can also make the wearer feel isolated or uncomfortable, increasing the chance that protection is worn incorrectly or removed.
Use the noise assessment and the manufacturer's SNR and HML data to select suitable protection. Our SNR vs HML hearing protection guide explains how those ratings differ.
Practical warning signs
If people need to raise their voices to be heard at a short distance, or if machinery, impact tools or alarms make communication difficult, the area may need a formal noise assessment. This is only a warning sign, not a reliable substitute for measurement.
Important reminder
This page is general information for UK workplaces. It is not legal advice and does not replace a competent noise assessment, current HSE guidance, employer responsibilities, product instructions or a hearing-conservation policy. Review the requirements for your industry and working environment before selecting controls or PPE.