Standards for hearing protection at work - EN 352 and its revisions
The phrase ‘hearing protection’ has a very specific meaning in the UK’s noise legislation and it must be certified to EN 352.
Key points: standards for hearing protection
Hearing protection must be certified to one of the branches of EN 352.
EN 352 is the technical standard for how hearing protection performance is tested.
The current revision of EN 352 is the 2020 one, this replaced the 2002 and 1993 versions.
Hearing protection must have a Declaration of Conformity certificate which confirms it meets EN 352, and this should be the 2020 version of EN 352.
With a Declaration of Conformity, UKCA and/or CE marks can then be used.
Hearing protection must carry either a CE or UKCA mark. Either one alone or both together are acceptable.
UKCA and CE marking
To misquote a famous line from the bad tempered human-eating big fish film, just when you thought it was safe to go back in the water, Brexit rears its head again.
The pre-Brexit standard was EN 352 and its various sub-divisions, and all hearing protection had to be certified to EN 352 in order to be used at work, and when things comply with EN 352 they get that all-important CE mark.
Post-Brexit we developed the UKCA standard which is the UK’s version of the EU’s CE mark. (UKCA means UK Conformity Assessed).
CE marking for PPE has been accepted in the UK indefinitely
The plan initially was for only the UKCA mark to be accepted. The recognition of CE marking was due to expire in 2024 and only UKCA marking would have been accepted from then on however this was modified to become an indefinite recognition of CE marks.
This means PPE, including hearing protection, can be marked with UKCA or CE - sometimes both or sometimes one or the other depending on how it was actually certified.
Both UKCA and CE are therefore acceptable markings.
More information: UK Government guidance on CE marking for PPE
The foundation of UKCA and CE is EN 352
A key element is that both UKCA and CE use EN 352 as the standard for the certification - if a product meets EN 352 it can be CE and/or UKCA marked. EN 352 is the foundation of both marking systems, hence the UK’s continued recognition of the CE mark.
Basically, the UK said ‘we’ll have our own certification mark as we like that kind of thing, but we’ll use the existing European standard for all the detail’. This means the actual detail of how hearing protection is certified falls under EN 352, as it always did, whatever the marking system used.
This makes sense really. If we had our own version of EN 352 which differed from the EU’s, then the UK would probably have fewer hearing protection manufacturers going through the hassle of separate certification. EN 352 is perfectly good so doubling up on it for no real benefit was sensible.
EN 352:2020 subsections and main requirements
This standard deals with all the detail of how hearing protection is tested and sets out what hearing protection performance is assessed against. There are three main sub-divisions within it:
EN 352-1: Covers ear muffs
EN 352-2: Covers ear plugs
EN 352-3: Covers ear muffs attached to a helmet
There are a few other sections as well which cover things like active ear muffs (ones where the noise protection kicks in when external noise reaches a certain level), or ones with bluetooth audio playback, etc. There are all numbers EN 352 and then ‘-4 to 8’.
There are loads of requirements within each one of those dealing with the specific product.
For ear muffs it includes things like construction materials, pressure on the head, can you set fire to them (burning ear muffs are considered something to avoid).
For ear plugs it is much the same, and for reusable plugs the standard looks at whether cleaning them reduces their effectiveness. Again interestingly, it specifically tests whether ear plugs can be ignited - I guess if burning ear muffs is bad then burning ear plugs are even worse.
3M have an excellent guide on this here: 3M guide on EN 352 testing
The year of the EN 352 standard is important
EN 352 is not static and does get revised, with the most recent revisions being 1993, 2002 and 2020.
EN 352:2020 is the current version and any hearing protection now being certified should be to that and not to the superseded 2002 or 1993 revisions.
The Declaration of Conformity
When a product is tested to EN 352 and passes then a Declaration of Conformity can be issued. That permits the manufacturer to use the necessary UKCA or CE marks.
The Declaration of Conformity generally lasts for five years, but with the important caveat of ‘unless the product is changed or the underlying standard is revised’.
I should flag that there are some conflicting statements online about how long a Declaration of Conformity is valid for and getting a clear answer is hard. Some sources state that a Declaration of Conformity is actually of an unlimited duration, but then with the same caveat of ‘unless the product or underlying standard changes’.
Either way, whether the Declaration of Conformity lasts for five years or is unlimited doesn’t matter, as the proviso of ‘unless the standards change’ then applies. The updating of EN 352 to the 2020 version triggers this recertification requirement.
Transition period between EN 352 standards
The 2020 EN 352 standard gave a grace period for PPE manufacturers to make the switch for their Declaration of Conformity to the 2020 version from the previous ones.
The transition period for certifying products to the older 2002 version ended on 21st January 2023.
New products put onto the market within that period had to be certified to the 2020 standard.
If a manufacturer had an existing product line which had been made continually both before and after the changes to EN 352, then they had until 21st January 2023 to update their Declaration of Conformity to the new 2020 EN 352 standard.
Existing stocks of hearing protection
A hearing protector could have been certified to the older 2002 standard up to the 20th January 2023, and purchased by an employer up to that date, or even after it depending on how fast the supply chain moves.
An employer could therefore still have stocks of hearing protectors stating the older 2002 standard as they were made or purchased before the transition deadline and they will still be within their usability shelf-life. They are OK to use.
Date of Manufacture vs EN 352 revision
Hearing protection has a Date of Manufacture on it and if this is after January 2023 then it definitely should be stating the 2020 revision of EN 352.
1993 version of EN 352
Ear muff with EN 352:1993
If you see a hearing protector stating the 1993 version of the standard, that has been out of date for a long time now.
Hearing protection has a limited life span and anything stating it is certified to the 1993 revision will be beyond its usable life now so should be disposed of.
There is more information here on the expected life span of hearing protection.
Practical impact on SNR levels of changing EN 352 standards
One outcome of the EN 352 standard is the assigning of an SNR to the hearing protector. SNR is the Single Number Rating, a measure of how effective the hearing protector is at reducing noise levels.
The change in the standards did have a practical impact on certified SNR levels. For example:
The EAR Classic ear plug (the yellow foam ones which have been around since the dawn of time) had an SNR of 29 dB on the older 2002 version of EN 352, but it is now 31 dB on the new one.
Similarly, the Beeswift BBED muff had an SNR of 28 dB under the 2002 standard, while it is 27 dB under the current one.
Moldex’s Comets changed by 2 dB between standards.
What information you need for hearing protection
When choosing hearing protection you need to make sure it has:
UKCA and/or CE marking.
An SNR figure.
A Declaration of Conformity.
Normal music headphones are not EN 352 certified
That does mean normal noise cancelling headphones are NOT hearing protection as they are not tested and certified to EN 352. So no AirPods, Bose QuietComfort, Sony XMwatever-the-latest-number-is, and so on, none of those are certified as hearing protection.
FAQ: Standards for hearing protection
My headphones are noise cancelling, can I wear those at work instead?
If you work in a low noise environment then there is nothing stopping you wearing them. If you work in a high noise environment then no, they cannot be worn as they do not have a certified SNR figure, they do not class as hearing protection.
Apple refer to the AirPods as having a hearing protection function, are they OK for work?
Again, no. Apple’s use of ‘hearing protection’ is a little naughty as they are not certified as hearing protection. ‘Hearing protection’ as a term has a very specific meaning and AirPods do not meet this. If Apple could get the AirPods certified I am sure they would as the potential market for people to then use them at work would be huge. I am sure that will come at some point, just not yet.
Why is it OK to have ear muffs which have Bluetooth functions but not headphones?
The ear muffs (such a the ISOTunes range) are hearing protection first and foremost. They have a certified SNR and also have volume limits for the internal playback.
More information on hearing testing at work
Article last updated May 2026 - information on transition periods.
