Guide
Carry out a noise risk assessment
Step-by-step guide to carrying out a noise risk assessment under the Control of Noise at Work Regulations 2005. Covers when an assessment is needed, identifying noise sources, estimating exposure, comparing against action values, and recording your findings.
You must carry out a noise risk assessment if any of your employees are likely to be exposed to noise at or above the lower exposure action value of 80 dB(A) daily or weekly average, or 135 dB(C) peak sound pressure. This is a legal requirement under the Control of Noise at Work Regulations 2005.
A noise risk assessment does not always require expensive sound level meters. For many workplaces, you can estimate exposure using manufacturer data, HSE published noise levels for common activities, or the HSE noise exposure calculator. Formal measurements by a competent person are needed only where initial estimates suggest exposure may approach or exceed the action values.
Quick test: If you have to raise your voice to have a normal conversation with someone about 2 metres away, the noise level is probably around 80-85 dB(A) and you need to assess the risk.
When you need a noise risk assessment
You need an assessment if your employees are exposed to any of the following:
- Noisy machinery (woodworking, metalworking, printing, bottling, weaving)
- Power tools used for extended periods (grinding, drilling, cutting)
- Impact processes (hammering, pressing, forging, riveting)
- Engines and compressors in enclosed or semi-enclosed spaces
- Music and entertainment (live venues, nightclubs, orchestras)
- Noisy environments where conversation requires raised voices
- Workers who report ringing in their ears (tinnitus) after work
Industries where noise assessments are almost always needed: manufacturing, construction, woodworking, metalworking, printing, textiles, quarrying, agriculture, music and entertainment, call centres (acoustic shock risk).
Steps to carry out a noise risk assessment
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1. Identify noise sources and exposed workers
Walk through your workplace and list all significant noise sources - machinery, tools, processes, vehicles. Identify which workers are exposed, for how long, and whether exposure varies throughout the day or week. Include maintenance staff, cleaners, and visitors who may be in noisy areas.
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2. Estimate noise exposure levels
Use one or more methods to estimate daily noise exposure for each group of workers. Methods include: manufacturer noise data from equipment documentation (usually in the user manual), HSE published noise levels for common activities, the HSE noise exposure ready reckoner (available free online), or formal sound level meter measurements by a competent person. For most small businesses, the HSE ready reckoner with manufacturer data is sufficient as a first step.
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3. Compare exposure against action values
Compare your estimated exposure against the three thresholds: lower exposure action value (80 dB(A) daily average), upper exposure action value (85 dB(A) daily average), and exposure limit value (87 dB(A) taking account of hearing protection). If exposure varies day to day, you may use a weekly average instead of daily, provided the weekly average does not exceed 85 dB(A) and daily exposure never exceeds 87 dB(A).
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4. Identify who is at risk and assess the level of risk
For each group of exposed workers, determine whether their exposure reaches or exceeds any action value. Consider individual factors such as existing hearing damage, use of ototoxic substances (certain solvents and medications can worsen noise-induced hearing damage), and workers who are particularly sensitive.
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5. Identify and implement controls
Apply the hierarchy of noise control. First, try to eliminate the noise source (change the process). Then substitute quieter equipment (adopt a buy-quiet policy when purchasing new machinery). Then apply engineering controls (enclosures, barriers, damping, silencers). Then use organisational measures (limit exposure time, rotate workers, schedule noisy work when fewer people are present). Hearing protection is a last resort.
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6. Record your assessment
Record the assessment findings including noise sources, estimated or measured exposure levels, who is at risk, controls in place, and actions needed. You must keep this record and make it available to employees and their representatives.
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7. Review the assessment
Review when circumstances change - new equipment, changed processes, building alterations, or where health surveillance indicates hearing damage is occurring despite controls. There is no fixed review period, but review at least every 2 years as good practice.
Methods for estimating noise exposure
HSE noise exposure ready reckoner
The HSE provides a free online noise exposure calculator. You enter the noise level for each activity and the duration of exposure. The calculator gives you the daily noise exposure in dB(A). This is suitable for most workplaces where you have manufacturer noise data or published noise levels for your activities.
Sound level meter measurements
Where manufacturer data is not available, or you need more accurate results, arrange for a competent person to take sound level measurements. The person must be trained in noise measurement techniques and use calibrated equipment. Measurements should follow BS EN ISO 9612:2009.
Manufacturer noise data
Equipment manufacturers must provide noise emission data in their documentation. Look for the declared noise emission value in the user manual or technical specification. This gives the noise level under standard test conditions - actual workplace levels may differ depending on installation, workpiece, and environment.
HSE published noise levels
HSE publishes typical noise levels for common activities and equipment. These are useful for initial screening but should not replace workplace-specific measurements where exposure may be near the action values.
Recording and keeping your assessment
Your noise risk assessment record should include:
- Date of the assessment
- Who carried it out (and their competence)
- Noise sources identified
- Workers or groups exposed
- Estimated or measured exposure levels
- Comparison against action values
- Controls already in place
- Further actions needed and deadlines
- Date for review
The assessment does not need to be perfect - it needs to be suitable and sufficient. A proportionate assessment that identifies the main risks and leads to action is better than a technically detailed report that sits on a shelf.
Common mistakes
Jumping straight to hearing protection: The regulations require you to reduce noise at source first. Hearing protection is a last resort, not a first response.
Assessing the area, not the worker: Noise exposure is based on what the worker experiences over the day, not a single reading in one location. If workers move between noisy and quiet areas, calculate their time-weighted average.
Ignoring peak noise: Short, very loud noises (hammer blows, cartridge tools, pneumatic equipment) may exceed the peak action value of 135 dB(C) even if the daily average is low. Assess peak noise separately.
Failing to review: A noise assessment becomes invalid when circumstances change. New equipment, changed layouts, or building work can alter noise exposure significantly.