Fit Testing – is it really necessary?


Discussing Respiratory Protective Equipment (RPE) the Health and Safety Executive (HSE) state:

“Where RPE is used, it must be able to provide adequate protection for individual wearers. RPE can’t protect the wearer if it leaks. A major cause of leaks is poor fit – tight-fitting facepieces need to fit the wearer’s face to be effective.”

That’s why, here in the UK, if you are required to wear tight-fitting RPE in your job, your employer has a legal obligation under Control Of Substances Hazardous to Health (COSHH)that you are Fit Tested.

It is the law.

But what is a Fit Test?


The Fit Test

There are two primary methods of face Fit Testing in the UK. The Qualitative (taste) method and the Quantitative (particle counting) method.

Regardless of the method, a Fit Test works by assessing whether or not a particular tight-fitting respirator/mask fits a particular person. That is whether or not a seal is able to be formed around their nose/mouth. If a sufficient seal is not formed, leaks occur and contaminated air could pass into the wearer’s lungs.

To ensure the seal will hold, during the Fit Test the subject undertakes a number of different ‘exercises’. This is to mimic common actions they are likely to perform whilst wearing a respirator at work. Such as bending at the waist, deep breathing and talking.

If the subject passes their Fit Test, they receive a Fit Test Certificate, stating that they may wear that particular make/model of respirator at work.*

And if they fail, they may retest, try another make/model, acquire alternative protection (e.g. loose-fitting powered air) or must be excused from the task.


*People should be re-Fit Tested at least every three years, or sooner if their face changes shape, they lose/gain weight, have dental surgery or their H&S policy directs it.

But does it really make a difference?


The Research

A recent study found that when Fit Testing is not performed, respirators are much more likely to give inadequate protection. In some cases, as few as 31% of people tested were protected to a satisfactory level from potential hazards – due to leakage in their respirator not fitting properly.[1]

While some of that 69% will be inadequately protected because they were wearing a respirator that does not fit them; the vast majority are unprotected because they simply weren’t aware of how to put on the respirator properly in the first place.

A key component of Fit Testing is education. To ensure all wearers know how to properly don and doff their respirator.

For example, did you know that you if a man has not clean shaven his face at most 8 hours before his shift, he should not wear a tight-fitting respirator?


If you would like more information on Fit Testing, or to get Fit Tested yourself at our Northamptonshire Fit Test Centre, please get in touch.


[1] Coffey, C.C., Lawrence, R.B., Campbell, D.L., Zhuang, Z., Calvert, C.A. and Jensen, P.A., 2004. Fitting characteristics of eighteen N95 filtering-facepiece respirators. Journal of occupational and environmental hygiene, 1(4), pp.262-271.