RPE Fit Testing Training Course

Quantitative Controlled Negative Pressure (CNP) Method (Quantifit)

CNP is a method that has been established in the US for many years, but is relatively new to the UK. It works by creating and maintaining a negative pressure in the wearer’s mask and then measuring the leakage of air into the mask during an 8 second test period. This method can be used to fit test half-masks and full-face masks.

Under the HSE protocol (INDG 479) there are different challenge pressures for half-masks and full-face masks. An equivalent fit factor can be produced, so the result can be compared to HSE’s stipulated minimum fit factors.


Dust2noise is the only organisation in the UK to have a CNP RPE fit testing course – Fit2Fit Approved. The course is delivered by a Fit2fit Accredited CNP Fit Tester and Chartered Occupational Hygienist.


Contact us below for a CNP QNFT training quote

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