The performance of tight-fitting facepieces depends on achieving a good contact between the wearer’s skin and the face seal of the facepiece. 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. Inadequate fit will significantly reduce the protection provided to the wearer. Any reduction in protection can put the RPE wearer’s life in danger or may lead to immediate or long-term ill health.
Here at STS Group Ltd we use Qualitative testing. This a method based on the tasting or smelling of a bitter, sweet or odorous compound. It depends on the mask wearer being able to detect the test compound.
QLFT uses an aerosol of either a bitter tasting substance (Bitrex) or a sweet substance (Saccharine) to challenge the face seal whilst the wearer undertakes 7 exercises (in a hood to contain the test substance). If after the 7 exercises (7 minutes), the candidate has not detected (tasted) the test substance, then that is regarded as a pass and a fit factor of 100 is assigned. (NB it is part of the protocol that at the end of the test, the candidate is required to break the seal to demonstrate how effective the seal has been).
Certification – STS Group Certificate