What Is Facepiece Fit Testing?
It is a method for checking that a respiratory facepiece matches the person’s facial features and seals adequately to the wearer’s face.
What is the reason for face fit testing?
The performance of respiratory facepieces depends on achieving a good contact between the wearer’s skin and the face seal of the facepiece. Peoples’ faces vary signicantly in shape and size so it is unlikely that one particular type, or size of respiratory device, will fit everyone.
Inadequate fit will signicantly reduce the protection provided to the wearer. It is also useful for checking that a wearer can put on a respirator facepiece correctly. Correct fitting of the facepiece at all times is vital to prevent exposure.
How is fit testing carried out?
There are two basic methods of Respiratory fit testing: Qualitative and Quantitative Fit Testing.
Qualitive Fit Testing:
Is a simple pass/fail test based on the wearer’s subjective assessment of the leakage, via the face seal region, of a test agent.
These tests are relatively simple to perform and are suitable for half masks and disposable masks.
They are not suitable for full face masks.
Examples of qualitative fit testing methods: method based on bitter or sweet tasting aerosol; method based odour compounds.
Quantitive Fit Testing
They require specialised equipment and are possible on all types of masks including disposable masks, half and full face masks. Quantitative tests can give an objective assessment of facial fit and provide a direct numerical result called Fit Factor. Fit Factor is a measure of how well a particular facepiece seals against the wearer’s face.
A higher fit factor number means the facepiece achieved a good contact between the face seal and the face during the test.
Both Qualitative and Quantitative Fit Testing are approved by HSE and must be carried out by an experienced Fit2Fit accredited Fit Tester or a competent person trained to the HSE standard.