⏱️ Estimated reading time: 15 min
Key Takeaways
Enough to bring the noise at your ear to about 70–78 dB(A), and never below 70. Take your noise level, subtract the protector’s SNR, add 4 dB for real-world fit and check the result against HSE’s selection bands.
HSE suggests SNR 20 or less for 85–90 dB(A), 20–30 for 90–95 dB(A), 25–35 for 95–100 dB(A) and 30 or more for 100–105 dB(A). Above 100 dB(A), an earplug rated in the mid-20s belongs under ear defenders rather than on its own.
Yes. HSE says protectors that bring the level at the ear below 70 dB should be avoided, because people who feel cut off tend to pull them out to talk, and a protector in a pocket protects nothing.
Lab ratings come from carefully fitted protectors. Daily use is messier. HSE advises derating every protector by 4 dB, so the level at your ear is estimated as noise level minus SNR plus 4. The derating does not apply to peak noise.
When noise sits above about 100 dB(A), where HSE’s table asks for SNR 30 or more. A low-profile earplug worn under ear defenders adds a few decibels over the better device alone, not the sum of both ratings.
Under the Control of Noise at Work Regulations 2005, protectors must be made available from 80 dB(A) or a 135 dB(C) peak, provided and worn from 85 dB(A) or 137 dB(C), and exposure at the ear must stay below 87 dB(A) or 140 dB(C).
How much hearing protection do I need? Measure or look up your noise level in dB(A), pick a rating from HSE’s selection table, then subtract the protector’s SNR and add 4 dB for real-world fit. Aim for about 70–78 dB(A) at your ear, and never below 70.
On trade forums it usually comes up in a sharper form: is SNR 24 enough for an angle grinder? The answer is a sum, not a feeling. And it matters. HSE estimates that around 15,000 people in Great Britain have work-related hearing problems (Labour Force Survey, 2022/23 to 2024/25), and hearing lost to noise does not come back.
At Bollsen, we are a hearing protection brand trusted by 1,000,000+ people, and we make reusable earplugs for work, sleep, music and travel. We use our WorkPRO earplugs, German-tested, independently certified 24 dB, as the worked example because their full H, M and L values are published. If you work in construction, a factory or a warehouse, our workplace hearing protection hub has job-specific advice, guidance on noise levels, fit and UK rules, and our range of earplugs for work.
What do UK noise rules say about hearing protection?
Under the Control of Noise at Work Regulations 2005, employers must make hearing protection available from a daily or weekly exposure of 80 dB(A) or a 135 dB(C) peak, provide it and enforce its use from 85 dB(A) or 137 dB(C), and keep exposure at the ear below the 87 dB(A) and 140 dB(C) limit values. Only the limit values count the protection you wear, as Regulation 4 of the 2005 Regulations sets out. The law also expects noise to be cut at source first, with protectors covering whatever is left.
Our guide to the Control of Noise at Work Regulations 2005 goes through each duty from the worker’s side. What the regulations don’t say is how much protection you need.
How do you find out how loud your work is?
The number you need is your daily noise exposure in dB(A), ideally with the C-weighted level in dB(C) alongside it, and from 80 dB(A) upwards your employer’s noise risk assessment under Regulation 5 should already have that figure for your job. Ask for it before you buy anything.
A phone app gives a rough reading. That’s fine for deciding whether a hobby or a commute needs protection. Our chart on how loud are power tools (decibel chart) lists typical readings for grinders, saws and breakers, and most land between 95 and 115 dB(A).
What SNR do you need for your noise level?
HSE’s selection table matches the noise level at work to a Single Number Rating (SNR): SNR 20 or less for 85–90 dB(A), 20–30 for 90–95 dB(A), 25–35 for 95–100 dB(A) and 30 or more for 100–105 dB(A). You want to end up at about 70–78 dB(A) at the ear. HSE’s bare minimum is getting below 85.
| Noise level at work | HSE suggested SNR | Target at the ear | Estimate with an SNR 24 plug (level − 24 + 4) |
|---|---|---|---|
| 85–90 dB(A) | 20 or less | 70–78 dB(A) | 65–70 dB(A): risk of over-protection, a lower rating fits better |
| 90–95 dB(A) | 20–30 | 70–78 dB(A) | 70–75 dB(A): inside the target |
| 95–100 dB(A) | 25–35 | 70–78 dB(A) | 75–80 dB(A): just under HSE’s 25–35 band; fine near 95, toward 100 consider a higher rating or ear defenders over the top |
| 100–105 dB(A) | 30 or more | 70–78 dB(A) | Below HSE’s band on its own: wear WorkPRO under ear defenders |
HSE’s hearing protection guidance warns that the table is not appropriate where the noise has significant low-frequency content, naming press shops, generators and plant rooms. Those jobs need the HML method below. Sudden bangs fall outside the table altogether.
How do you work out the noise level at your ear?
The SNR method estimates the level at your ear as the noise level minus the SNR, and HSE then adds 4 dB for real-world fit, so a protector rated SNR 24 dB in a 95 dB(A) workshop gives roughly 95 − 24 + 4 = 75 dB(A) at the ear. Strictly, the SNR is subtracted from the dB(C) level. With only dB(A), the answer is approximate, as C-weighted readings for broadband tool noise usually run 0–3 dB higher.
Run it at two other levels. 90 dB(A) gives 90 − 24 + 4 = 70, right on the floor. 100 dB(A) gives 80, which is why HSE asks for SNR 30 or more there.
The 4 dB comes from HSE’s guidance on real-world factors, which notes that protectors rarely match their lab results in daily use. Shallow insertion, the wrong size or a broken seal all cost decibels (our guide on how to put earplugs in and check the fit covers that). HSE does not apply the 4 dB to peak noise.
If you’ve read American advice, you may have seen “subtract 7 and halve it”. That’s the US derating for NRR, a different rating from a different test. The two get mixed up a lot, and our explainer on NRR vs SNR explained shows how each rating is tested and why the two numbers are not interchangeable. For UK choices, stick with HSE’s flat 4 dB.
Riders do the same sum, except wind noise sets the level instead of machinery. Our SNR guide for motorcyclists applies the selection bands to helmet and road noise at motorway speeds.
What is the HML method and when should you use it?
The HML method uses three ratings printed for every EN 352-2 earplug, H for high-frequency noise, M for mid and L for low, together with both the dB(A) and dB(C) readings, and it gives a better estimate than the SNR when noise is tonal or low-heavy. Our WorkPRO earplugs are rated H 24, M 21, L 19.
Which formula you use depends on the gap between the two readings. If dB(C) minus dB(A) is 2 or less, the noise is high-pitched and the predicted protection is M − (H − M) ÷ 4 × (gap − 2). If the gap is more than 2, the noise is low-heavy and the protection is M − (M − L) ÷ 8 × (gap − 2). Either way it is an estimate, not a fit test.
Take an angle grinder at 95 dB(A) and 96 dB(C), a gap of 1. WorkPRO’s predicted protection is 21 − (3 ÷ 4) × (−1), about 22 dB, so the ear sees 95 − 22 + 4, roughly 77 dB(A). A generator room at 92 dB(A) and 100 dB(C) has a gap of 8, which gives 21 − (2 ÷ 8) × 6 = 19.5 dB and about 77 dB(A) at the ear once the 4 dB is added.
WorkPRO’s attenuation rises with frequency, from about 22 dB in the low and mid bands to 35 dB at 8 kHz, so it works hardest on high-pitched noise and less on deep rumble. Roughly, grinding and sawing sit near the H value and plant or engine noise nearer L.
For workshops and sites where daily exposure sits around 90–95 dB(A), our WorkPRO earplugs (SNR 24 dB, £29.95) are reusable, hypoallergenic silicone plugs with a low profile, so ear defenders fit over the top when the assessment calls for both. They’re one part of your employer’s noise plan, not a replacement for cutting noise at source.
Can you have too much hearing protection?
Yes. HSE treats over-protection as a real risk and says protectors that bring the level at the ear below 70 dB should be avoided, because wearers feel isolated and struggle to follow what’s going on around them. More decibels aren’t automatically better.
“If I can’t hear anything I just take them out to talk to my mate” is the kind of thing you read on worker forums. A plug that spends half the shift in a pocket only protects for half the shift. If your sum comes out below 70, pick a lower SNR, not the biggest number on the shelf.
A passive plug doesn’t choose what gets through. WorkPRO makes everything roughly 24 dB quieter, with higher pitches reduced most, so a loud warning stays audible because it is loud, not because a filter passes it through. Our separate guide to hearing a fire alarm with earplugs in covers alarms on site. Your employer’s assessment should confirm that warning signals can still be heard with protection worn.
What should you look for on a hearing protector’s label?
Earplugs certified for workplace use are tested to EN 352-2, and the packaging or leaflet shows the SNR, the H, M and L values and a table of mean attenuation at eight frequencies from 63 Hz to 8 kHz, which is the data both selection methods rely on. Ear defenders follow EN 352-1.
The octave table shows the shape of the protection. For WorkPRO it reads 21.9 dB at 63 Hz, 23.1 at 125 Hz, 21.8 at 250 Hz, 22.1 at 500 Hz, 23.2 at 1 kHz, 28.4 at 2 kHz, 29.3 at 4 kHz and 35.3 at 8 kHz. That rising curve is normal for a passive silicone plug, and it’s why H sits above L.
Type matters as much as the number. Foam, reusable silicone, banded and custom-moulded plugs reach their ratings in different ways, and our guide to the best earplugs for work compares them side by side.
When do you need double hearing protection?
You need double hearing protection, meaning an earplug worn under ear defenders, when noise sits above roughly 100 dB(A), where HSE’s table asks for SNR 30 or more and a single plug rated in the mid-20s no longer brings the ear into the target.
The two ratings don’t add together. A plug plus a muff gives only a few decibels more than the better device alone, partly because sound also reaches the inner ear through the skull bones. Our separate guide to double hearing protection goes through the combinations, and WorkPRO’s low profile lets a muff seal over it.
Sudden bangs are a different case. Peak noise is judged against the 135, 137 and 140 dB(C) values, HSE’s 4 dB derating does not apply to it, and neither the SNR table nor the sums above describe impulse noise. Jobs with heavy impacts need their own assessment.
Does the same rule work outside the workplace?
Yes. The same level minus rating plus 4 dB sum works anywhere, and you want the result below 85 dB(A) at the ear, roughly where the RNID says hearing damage can start. If you need a starting figure, our guide on how loud is too loud puts everyday sounds on one decibel scale.
At concerts and clubs, music often sits around 110 dB, and RNID warns that 100 dB can cause permanent damage after as little as 15 minutes. A plug rated in the mid-20s brings a 100 dB(A) set to around 80 at the ear, while right beside the speakers at 110 dB(A) the sum reaches about 90. Distance from the speakers matters as much as the rating.
Tube and bus journeys can reach 85–95 dB(A) at their loudest, and a rating in the low 20s is usually plenty: 90 − 22 + 4 = 72. Forum users often say a rating in the 20s covers everyday noise. For most commutes, the maths backs them up.
DIY tools are as loud at home as on site, at roughly 95–115 dB(A), so the loudest jobs call for a plug under ear defenders. Sleep is a different call. A snoring partner or night traffic sits well below the 80 dB(A) action value, so comfort on the pillow matters more than a high rating.
Fireworks and other sudden bangs are impulse noise, the same category as the peak values above, so the band table does not apply. Distance comes first, then protection, with children kept well back.
Ringing in the ears after a loud night means the noise dose was too high. If it lasts, or your hearing changes, see a GP. The NHS guidance on hearing loss advises wearing ear protection when exposed to loud noise. The same arithmetic applies to anyone weighing up earplugs for tinnitus concerns, because protection limits further noise exposure rather than changing ringing that is already there. Our hub on earplugs for tinnitus explains how to protect your hearing from further noise exposure at loud events, at work and at home.
So which SNR should you choose?
Start with your noise assessment, read the band off HSE’s table and check that level minus SNR plus 4 lands around 70–78 dB(A). If it falls below 70, step down to a lower rating. Above 100 dB(A), put a plug under ear defenders.
For the common 90–95 dB(A) band, WorkPRO’s SNR 24 dB lands inside HSE’s 20–30 band. As the noise climbs toward 100 dB(A), wear it under ear defenders. It comes with our 40-day money-back guarantee. Whatever you choose, the right protector is the one that stays in for the whole time the noise is on.
His connection to hearing protection stems from personal experience with sound sensitivity during live events and work in noisy environments, an issue that made him more aware of the long-term risks of unmanaged noise exposure. Today, as both a communicator and a user of BOLLSEN products, he is passionate about raising awareness around the importance of proactive hearing care.
At BOLLSEN, he develops data-driven marketing campaigns, writes SEO-focused articles, and manages communication channels that connect customers with practical knowledge about hearing protection. His work ensures that BOLLSEN’s message—prioritizing health, performance, and sustainability reaches a global audience in an engaging and trustworthy way.
Passionate about writing since childhood, Timotej combines creativity with a strong analytical approach, continuously testing new ideas in digital marketing, performance advertising, and social media. He believes in learning through innovation and collaboration, balancing leadership with openness to new perspectives.
Beyond his professional role, Timotej is committed to a healthy lifestyle and finds inspiration in fitness, sports, and quality time with friends. His personal passion for well-being aligns with BOLLSEN’s core values, making his work not only a career but also a cause he deeply believes in.