Fit testing basics
Where respiratory protective equipment (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.
As people come in all sorts of shapes and sizes it is unlikely that one particular type or size of RPE facepiece will fit everyone. Fit testing will ensure that the equipment selected is suitable for the wearer.
For more detailed information on fit testing RPE, read our Guidance on respiratory protective equipment (RPE) fit testing INDG479.
When you need to do fit testing
The best time to do fit testing is at the initial selection stage, when individual users can be given a choice of adequate models of RPE. You should ensure the make, model, type and size of facepiece the employee wore when they had their successful fit test is made available for their use.
If an employee wears more than one type of tight-fitting facepiece, then each type of facepiece should be fit tested.
How to carry it out
RPE fit testing should be conducted by a competent person – you should take steps to ensure the person who carries out the fit test is:
- appropriately trained, qualified and experienced
- provided with appropriate information to carry out each particular task
The British Safety Industry Federation (BSIF) has a scheme for fit testers. This may provide evidence to help you decide whether a fit tester is competent.
A note on facial hair
Many masks rely on a good seal against the face so that, when you breathe air in, it is drawn into the filter material where the air is cleaned. If there are any gaps around the edges of the mask, 'dirty' air will pass through these gaps and into your lungs. It is therefore very important that you put your mask on correctly and check for a good fit every time.
Facial hair – stubble and beards – make it impossible to get a good seal of the mask to the face.
If you are clean-shaven when wearing tight-fitting masks (those which rely on a good seal to the face), this will help prevent leakage of contaminated air around the edges of the mask and into your lungs. You will therefore be breathing in clean air, which will help you stay healthy.
If there are good reasons for having a beard (such as for religious reasons), alternative forms of RPE, that do not rely on a tight fit to the face, are available.
Maintaining hygiene of face fit testing kit
Fit testers should familiarise themselves with the following actions to ensure hygiene of face fit testing kit is maintained:
Inside and outside of respirator (mask)
The fit tester should clean the inside and outside of the mask using suitable disinfectant cleaning. You may wish to wear disposable gloves.
Inside and outside (where held) of hood used for qualitative fit tests
The fit tester should clean the inside and outside (where held) of the hood between each test using a suitable disinfectant wipe that won’t damage the visor. You may wish to wear disposable gloves.
Moisture from the wearer’s breath collected inside the ambient particle counting device tubing (for quantitative testing)
You may wish to wear disposable gloves to remove used tubing. Clean the mask end of the tube with a suitable disinfectant wipe after use.
Have a stock of spare tubes (to allow used tubes to dry). Alternatively, ensure the end of used tubing is placed in a wad of tissue if removing the condensate between tests by blowing out with compressed or canned air.
Fit testing adaptors and sampling probe
Clean these at the same time as cleaning the mask following the fit test using a suitable disinfectant cleaning wipe, or solution.
Specific inner mask supplied by fit tester when fit testing powered RPE and the existing inner mask is replaced
You should clean this at the same time as you clean the inside of the mask using a suitable disinfectant cleaning wipe or solution.
Filters
The wearer’s exhaled air does not pass through the filters used when testing half and full facemasks. However, they may be re-used and handled between tests and so should be wiped using a suitable disinfectant cleaning wipe or solution.
Video about putting on respirators and fit checking
This video demonstrates the importance of:
- selecting the right respirator for the work being done
- conducting testing of tight-fitting RPE to individual wearers
- ensuring a proper seal to the face
Video on the Face Fit Respirator Demonstrator Model (FFRED)
This video demonstrates the importance of:
- fitting your respirator correctly
- conducting face fit testing of tight-fitting RPE to individual wearers
- ensuring a proper seal to the face
- considering other personal protective equipment (PPE) worn in conjunction with the respirator
It is important that your respirator is adequate and suitable for the work being carried out.