How often you need to repeat a noise assessment
The Control of Noise at Work Regulations 2005 say a noise assessment shall be done and that it shall be repeated when needed.
Key points on when to repeat a noise assessment
The Noise Regulations do not put an expiry date on noise assessments.
They say you shall review it regularly, at least every two years. You can do that yourself.
I recommend the in-house review is done annually. If you decided nothing has changed then you are good for another years. Document that you did it. If you decide the noise risk may have changed then do a new noise assessment.
I recommend repeating the noise assessment around every three years. Even if nothing has changed things like wearing bearings, air leaks, loose panels, etc. can change the noise levels, sometimes significantly.
When to repeat, review or redo a noise assessment.
A noise assessment does need to be reviewed and then redone / repeated sometimes, but you don’t always have to get someone in to do that for you.
Most companies can review the noise assessment themselves and if nothing has changed you are good to go.
A complete repeat of the noise assessment can be less frequent and is based a little more on how big the noise risk is on the site.
Noise assessments do not automatically ‘expire’.
HSE’s law and guidance on repeating a noise assessment
The HSE have some law covering this, and then also explanatory guidance.
Extract from L108: What the HSE say about repeating a noise assessment
Extract from L108: HSE's guidance on when to repeat or review a noise assessment.
The guidance in L108 expands further and gives a bit more detail.
My recommendations on repeating or reviewing a noise assessment
I think it is helpful to break it down into ‘review’ and ‘repeat’.
Reviewing a noise assessment
This is the more frequent one and this can usually be done in-house. I would recommend that every year, have a look at the workplace and see if anything has changed. For example:
Are there new machines?
Has the layout of the machines or the building itself been changed as that can impact on noise?
Have the runtimes of the machines changed?
Have shifts changed and people are maybe working a longer shift or doing more overtime?
Are there any audible differences?
Are your hearing tests showing a potential problem with a lot of people ‘failing’?
Are you generally busier? Getting busier may mean less down-time and more consistent or faster running.
If all the answers are ‘no’, then that is your review of the noise assessment done.
If answers are ‘yes’ then you should get a new noise assessment done.
Important: Document that you did it, either in safety meeting minutes or ideally on the main noise risk assessment document. If you are asked you can then show that on a certain date it was done and you considered there to be no changes and that the existing noise assessment is accurate.
Repeating a noise assessment from scratch
Every so often a noise assessment should be done from scratch again as there are always slight changes which creep in. For example, motors making more noise, bearings wearing, air lines starting to leak a little, panels working loose, etc. Often the annual noise assessment review misses these so a less frequent repeat of the entire noise assessment will catch that.
In my noise assessments I give a broad rating for how dangerous the noise risk is on the site, being low, medium or high.
For sites identified as low risk I recommend repeating the noise assessment every four years.
For sites identified as medium risk I recommend repeating the noise assessment every three years.
For sites identified as a high risk I recommend repeating the noise assessment every two years.
Also, repeat it if you annual in-house review has highlighted any causes for thinking the noise exposure levels may have changed.
FAQ: When to review or repeat a noise assessment
The people who did the last noise assessment put an expiry date on it, can I ignore that?
Yes. I would assume they put a two year date on it. What the HSE say is that the noise assessment should be reviewed at least every two years, but you can review things yourself. A review doesn’t mean it has to be re-done from scratch.
More help and advice on noise assessments
Article last reviewed and updated April 2026
