What Counts as an Acceptable Noise Level at Work? UK Thresholds, the dB Scale, and When You Must Act

"How loud is too loud?" is the question most employers actually have when they first look at workplace noise — before the regulations, before the calculators, before the surveys. It is also a question with a precise UK answer, because the Control of Noise at Work Regulations 2005 set fixed sound levels at which specific duties begin.

This guide explains what "acceptable" means for workplace noise in plain English: how the decibel scale behaves, the rough levels common workplace sounds reach, and the exact thresholds at which UK law requires you to act. It is a reference for deciding whether you have a noise problem at all — not a substitute for a noise risk assessment, which is what the law requires once you do.

This guide explains UK workplace noise thresholds under the Control of Noise at Work Regulations 2005. It helps you judge whether noise is likely to be a problem in your workplace; it does not replace a competent noise assessment where exposure is significant, variable, or close to the action and limit values.

There is no single "acceptable" noise level — there's a set of thresholds

It is tempting to want one number: the level below which workplace noise is "fine" and above which it isn't. UK noise law doesn't work that way, and for a good reason — hearing damage depends on both how loud the noise is and how long someone is exposed to it. A brief loud burst and a quieter sound sustained for a full shift can cause comparable harm.

So instead of one acceptable level, the regulations set action values — sound levels at which employer duties switch on — and an exposure limit value that must not be exceeded. Whether a noise level is "acceptable" depends on which of these thresholds the worker's exposure crosses.

The important distinction is between two ways of measuring noise:

• Average exposure over the working day or week — written as a daily or weekly personal noise exposure in dB(A). This is what the action and limit values are mostly built around, because it captures the loud-plus-duration combination that drives hearing damage.
• Peak sound pressure — written in dB(C). This captures sudden, very loud impulses (a nail gun, a press, a metal-on-metal impact) that can damage hearing instantly, regardless of how short they are.

A workplace can be acceptable on average exposure but still breach a peak value, or vice versa. Both matter.

How the decibel scale works (and why "twice as loud" is misleading)

The decibel scale is logarithmic, which trips up a lot of first-time assessments. Three things follow from that:

1. Small dB numbers represent large changes in sound energy. A 3 dB increase represents roughly a doubling of sound energy. A 5 dB difference — say, the gap between 80 and 85 dB(A) — represents roughly three times the sound energy (because the scale rises by a factor of about 3.16 for every 5 dB). The thresholds are close together as numbers but far apart in physical terms.
2. You can't simply add decibel readings together. Two machines at 85 dB(A) running side by side do not produce 170 dB(A) — they produce about 88 dB(A). Combining noise sources is logarithmic arithmetic, which is one reason a calculator helps.
3. The A-weighting (the "A" in dB(A)) matters. dB(A) adjusts the raw sound measurement to reflect how the human ear actually perceives different frequencies. It is the weighting the regulations use, so a "decibel level" quoted without the A-weighting can be misleading.

This is why a "noise level chart" of everyday sounds is only ever a rough guide: real workplace exposure depends on the mix of sources, the time spent near each, and the frequencies involved.

A rough guide to common workplace noise levels

The following are indicative levels for common workplace sources — useful for a gut check, not for an assessment. Actual levels vary widely by equipment, age, maintenance, and how close the worker stands. The figures below reflect the kind of ranges HSE and equipment manufacturers commonly cite.

Rough sound level	Typical source	What it suggests
60–70 dB(A)	Normal conversation, an office	Well below any action value
75–80 dB(A)	Busy workshop background, a vacuum cleaner	Approaching the lower action value
80–90 dB(A)	Circular saw, angle grinder, food-processing line	Likely at or above the lower or upper action value
90–100 dB(A)	Chainsaw, pneumatic tools, woodworking machinery	Well above the upper action value
130 dB(C)+ peak	Nail gun, cartridge tool, metal press impact	May breach a peak action value instantly

A widely-used field check that needs no equipment: if you have to raise your voice to have a normal conversation with someone roughly an arm's length to a couple of metres away, the noise is loud enough to take seriously and may well be around the upper action value. If you have to shout to be heard, levels are likely higher still. This is only an indicator that noise is likely to be a problem — it is not a measurement and it does not confirm a specific dB level.

A rough check like this tells you whether noise is likely to be a problem and whether a proper look is warranted. It does not tell you a worker's actual exposure — that needs the time spent at each level factored in, which is what a noise risk assessment does.

The UK thresholds: where duties actually begin

Once a rough check suggests noise might be an issue, the precise thresholds are what decide your duties. They are set in Regulation 4 of the Control of Noise at Work Regulations 2005, and HSE summarises the employer duties on its noise regulations page:

• Lower exposure action value — 80 dB(A) daily or weekly average (and 135 dB(C) peak). At this level you must assess the risk to workers' health and provide information and training. Hearing protection must be made available on request.
• Upper exposure action value — 85 dB(A) daily or weekly average (and 137 dB(C) peak). At this level you must put a programme of control measures in place to reduce exposure, provide hearing protection, and designate and mark hearing protection zones where its use is mandatory.
• Exposure limit value — 87 dB(A) daily or weekly average (and 140 dB(C) peak). This is the level workers must not be exposed to. Crucially, the exposure limit value is the only one of the three that is assessed taking account of the reduction provided by hearing protection — the action values are assessed on the noise reaching the worker without protection.

That last point is the one most often misread. Hearing protection does not lower your assessment against the 80 and 85 dB(A) action values — those duties are about the noise in the workplace, not the noise at the protected ear. Protection only counts toward the 87 dB(A) limit value. So issuing earplugs does not make an 88 dB(A) workshop "acceptable" on paper; the upper-action-value duties still apply, and the protection is one of the controls, not a way to mark the box as solved.

For a fuller breakdown of what each threshold triggers in employer duties — and how the action and limit values differ in practice — see UK Workplace Noise Exposure Limits: Action Values and What They Mean for Employers.

So what is an "acceptable" noise level?

Putting it together:

• Below 80 dB(A) average exposure (and below 135 dB(C) peak): noise is generally acceptable, with no specific noise duties beyond the general duty to assess significant risks. You should still note it if it's close to the threshold.
• 80–85 dB(A) average: not "unacceptable", but you have crossed the lower action value — you must assess, inform, train, and offer hearing protection.
• 85 dB(A) and above average (or 137 dB(C) peak and above): you must actively reduce exposure and control it — this is where the real compliance work begins.
• 87 dB(A) and above at the worker's ear after protection (or 140 dB(C) peak): the exposure limit value is exceeded. That is a breach, not a flag — you must take immediate action to bring exposure back within the limit and find out why it was exceeded.

"Acceptable" is therefore a moving target tied to a specific worker's average exposure and the peak impulses they're subject to — not a property of the room. A loud workshop where a worker spends only 30 minutes a day can produce a lower personal exposure than a moderately noisy line worked for a full shift.

How to find out your actual levels

A chart and a voice test get you to "we probably have a noise problem." Getting to a defensible figure means working out personal exposure — the level each worker actually receives, averaged over their working day or week, factoring in time at each task.

That is a calculation, and NoiseProof's free Noise Exposure Calculator runs it in the browser: enter the noise level and time for each task and it returns the daily personal noise exposure to compare against the thresholds above. For the official downloadable tool and how to interpret it, see The HSE Noise Calculator Explained. And for turning those figures into the assessment record the regulations require, see How to Complete a Noise Risk Assessment.

If exposure lands close to an action or limit value, or noise varies a lot through the day, an estimate is not enough — a measurement is more defensible. The DIY vs consultant decision covers when to bring one in.

Sources

• Control of Noise at Work Regulations 2005, Regulation 4 (exposure limit values and action values) — legislation.gov.uk
• Noise at work: the regulations — HSE
• Noise at work: employers' responsibilities — HSE
• Noise at work: how do I assess the risks? — HSE
• INDG362: Noise at work — a brief guide to controlling the risks — HSE