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LEV testing - the wider control
Masks feel like the obvious answer to a dusty or fume-filled job. In the control hierarchy they are close to the last one - and understanding why puts LEV, RPE and face-fit testing in their proper order.
The short answer
In the COSHH control hierarchy, extraction that controls exposure at source - LEV - comes before respiratory protective equipment (RPE) worn by the individual. RPE is closer to a last resort, used where LEV alone cannot adequately control exposure or as a supplement to it. Where RPE is relied on, face-fit testing proves the mask actually seals to the wearer's face. LEV protects everyone; RPE protects one person, only if it fits.
The hierarchy
COSHH sets out a hierarchy for controlling exposure, and it is not a menu to pick from - it is an order of preference. Prevent exposure if you can; if not, control it by engineering means such as LEV that capture the contaminant at source; then by ways of working; and only as a last resort by personal protective equipment such as RPE. The logic is that controlling a hazard at source protects everyone in the area, while a mask protects only the person wearing it, and only while they wear it correctly.
So RPE sits near the bottom of the hierarchy, not the top - which is the opposite of many people's instinct, since a mask is the visible, obvious response to dust or fume. Reaching for RPE first, and treating LEV as optional, inverts the order COSHH intends. The proper approach is to control exposure at source with LEV first, and use RPE where that is not enough.
Why LEV comes first
LEV is preferred because it deals with the contaminant itself - drawing it away at source before anyone breathes it, protecting the whole work area and everyone in it, and not depending on individual behaviour. Once installed and working, it protects continuously without anyone having to remember to do anything. That is a fundamentally more reliable control than equipment worn by each person.
RPE, by contrast, protects only the individual wearing it, only when they are wearing it, and only if it fits and is used correctly. It does nothing for anyone nearby, it fails the moment it is removed or worn wrong, and it relies entirely on the wearer. Those are real limitations, which is exactly why RPE is a backstop for where source control cannot fully do the job, not the primary control.
Where RPE fits
RPE has a genuine and important place - it is just not the first place. It is used where LEV alone cannot adequately control exposure, for tasks or situations engineering controls cannot fully reach, as a supplement during higher-exposure activities, or as interim protection while a control problem is put right. In those roles it is essential, and choosing the right RPE for the hazard matters.
But RPE used well is RPE used within the hierarchy, not instead of it. Relying on masks to compensate for LEV that is inadequate or untested is using the last resort to paper over a failure of the primary control - which is both worse protection and, in COSHH terms, the wrong way round. RPE supports good source control; it does not substitute for it.
Face-fit testing
Where tight-fitting RPE is used, it only protects if it seals to the wearer's face - and faces differ, so a mask that seals on one person may leak on another. Face-fit testing is how that seal is proven: a test confirming that a particular mask fits a particular person well enough to protect them. Without a fit test, a mask is protection assumed rather than protection proven, and a mask that leaks offers a false sense of safety worse than none.
So face-fit testing is to RPE what a thorough examination is to LEV: the check that confirms the control actually works. A tight-fitting respirator relied on without face-fit testing is an unverified control, just as an LEV system relied on without testing is. Where RPE is part of the picture, fit testing is what makes it a real protection rather than a hopeful one.
The takeaway
The proper order is clear: control exposure at source with LEV as the primary engineering control, keep it tested and maintained so it genuinely works, and use RPE as a backstop where source control cannot fully do the job - with face-fit testing to prove the mask actually protects the wearer. Each has its place, but the places are not interchangeable, and RPE is not a substitute for good, tested LEV.
For a duty holder, that means investing first in LEV that controls exposure at source and having it properly tested, then using RPE and face-fit testing where the hierarchy calls for them. Getting the order right - source control first, personal protection as backstop - is what actually protects people, rather than relying on masks to cover for extraction that should have been doing the job.
Questions
LEV. In the COSHH control hierarchy, engineering controls that capture exposure at source come before personal protective equipment worn by the individual. RPE is closer to a last resort, used where LEV alone cannot adequately control exposure.
Because it deals with the contaminant at source, protecting everyone in the area continuously without relying on individual behaviour. A mask protects only the wearer, only while worn correctly, and does nothing for anyone nearby.
Where LEV alone cannot adequately control exposure, for tasks engineering controls cannot fully reach, as a supplement during higher-exposure work, or as interim protection while a control problem is fixed - as a backstop within the hierarchy, not instead of it.
A test confirming a particular tight-fitting mask seals well enough to a particular person's face to protect them. Faces differ, so a mask that seals on one person may leak on another - a fit test proves the seal rather than assuming it.
Because tight-fitting RPE only protects if it seals, and a mask that leaks offers a false sense of safety worse than none. Fit testing is to RPE what a thorough examination is to LEV - the check that confirms the control actually works.
No. Relying on masks to compensate for inadequate or untested LEV uses the last resort to cover a failure of the primary control - worse protection and the wrong way round. RPE supports good source control; it does not substitute for it.
We test the LEV that should be your first line - so exposure is controlled at source and RPE is a genuine backstop, not a cover.
