If my air quality survey report comes back and tells me that we are below the Workplace Exposure Limit but the surveyor tells me that anything above 10% of the work place exposure limit is classed as uncontrolled, do i have to take any further action if i am under the WEL. The report suggests FFP3 fitted masks. The issue i have with this suggestion is that tight fitting masks are only suggested for short duration work no more than 1 hour and obvious th problem of of making sure that any wearers are clean shaven every day. 

WEL is not a target nor an "accepted" condition.

COSHH is about as low as is reasonably practicable ideally with a zero aspiration by elimination of the hazard.

There will be other things you can do in plcae of fitted masks.

It depends on what sort of operation you are doing.

If you occasionally expose workers for a short period of time to an airborne hazardous substance that some sort of  negative pressure face mask is acceptable. This particularly makes sense if if you are not working on a fixed site. On the other hand if this is a routine activity happening over a significant part of the day then you need to look at a better solution. So go through the hierarchy of controls, starting with seeing if there are any alternatives to the substances you are using. If that’s a nonstarter the move onto some form of LEV, including a total or partial enclosure of the process.  A local extraction system(trunk) might work but you have to make sure that the receiver is close to the work activity. Then you look at positive pressure system. Note that with disposable face masks, you need to dispose of them regularly sometimes getting through more than one a shift and usually not recommended to wear a disposable face mask for more than an hour, as the seal starts to fail.

Hi Gaz

I am very puzzled by this idea that exposure at 10% of a designated Workplace Exposure Limit [‘WEL’} might in general be deemed “uncontrolled”.

Regulation 7 of COSHH 2002 as amended starts:

Prevention or control of exposure to substances hazardous to health

7.—(1) Every employer shall ensure that the exposure of his employees to substances hazardous to health is either prevented or, where this is not reasonably practicable, adequately controlled.

……after much more we get to:

       (7) Without prejudice to the generality of paragraph (1), where there is exposure to a substance hazardous to health, control of that exposure shall only be treated as adequate if—

(a) the principles of good practice for the control of exposure to substances hazardous to health set out in Schedule 2A are applied;

(b) any workplace exposure limit approved for that substance is not exceeded; and

(c) for a substance— (i) which carries the [F31hazard statement H340, H350 or H350i], or for a substance or process which is listed in Schedule 1; or (ii) which carries the [F32hazard statement H334], or which is listed in section C of HSE publication “Asthmagen? Critical assessments of the evidence for agents implicated in occupational asthma” as updated from time to time, or any other substance which the risk assessment has shown to be a potential cause of occupational asthma, exposure is reduced to as low a level as is reasonably practicable.]

Schedule 2A was added in 2004 and, in effect, says that you should apply the hierarchy of control measures applicable to mitigating ANY risk.

So, if we ignore that, then Reg 7(7)(b) says that you have “adequate control” [by airborne exposure] if the exposure is below the WEL - UNLESS Reg 7(7)(c) also applies e.g. if you are dealing with e.g. a designated carcinogen, mutagen or asthmagen, in which case not only do you have to make sure that exposure is below the WEL but also as low as reasonably practicable.

Arguably reducing the exposure to the lowest that is reasonably practicable will apply to any scenario - if you wish to comply with the overarching legislation, HSWA.

However, some arbitrary idea that you have to get down to 10% of WEL before you can consider that the exposure is “adequately controlled” appears to me to be nonsensical!

Does your surveyor have commercial reasons to wish to push RPE or any other PPE?

For almost the entirety of my working life, much of my time has been spent on often trying to find solutions to avoid the need for any PPE!

Edited by user 21 January 2025 15:17:32(UTC)  | Reason: Formatting for ease of reading