Fit testing is a practical examination to ensure a tight-fitting respirator mask can properly seal around a wearer’s face and is therefore suitable for the individual.
As people and respirators come in a variety of different shapes and sizes, not every facepiece will fit every person. Therefore, it is essential that a person be fit tested per make/model of respirator mask, in order to confirm that a tight-seal is achievable. If a tight-seal is not achievable, that type of respirator will not provide it’s intended protection, leaving the subject vulnerable to harm or even death.
Please note: a fit test will not assess whether a respirator mask is adequate for the situation, only that it is suitable for the wearer.
There are two standard methods of Fit Testing in the UK. The qualitative fit test (QLFT) which measures taste and the quantitative fit test (QNFT) which measures the volume of particles. QNFT can then be categorised into those that measure ambient particle count (APC) and those that measure controlled negative pressure (CNP).
QLFT and QNFT-APC are the most common forms of fit testing used in the UK.