The INDG 479 Fit Test Protocol

Fit Test Exercises

INDG 479 states that the Fit Test protocol must include a minimum of seven test exercises, which should be performed for at least one minute each. The wearer must achieve an individual pass result in each of the seven test exercises within one single testing period. ie if a single one of the exercises fails then the whole test must be repeated. 

Download INDG 479 from the HSE website (PDF)

The fit test exercises for both Qualitative and Quantitative tests are:

  • Normal Breathing
  • Deep Breathing
  • Head Side to Side
  • Head Up and Down
  • Talking
  • Bending
  • Normal Breathing

INDG 479 states that for a Quantitative (Ambient Particle Counting) fit test, these exercises should be performed while the candidate is performing a dynamic movement such as: cycling on an exercise bike, walking on a treadmill or carrying out a stepping exercise. The exercise regime should induce a physical workload on the wearer which aims to simulate working activities and work rate.


Fit Factor Pass Levels

The minimum Fit Factor which must be achieved to pass a fit test depends upon the type of facepiece being tested:

  • Half Mask and FFP3 Disposable Mask, Fit Factor Pass Level = 100*
  • Full Face Masks (All types), Fit Factor Pass Level = 2000

*When using a PortaCount, APF 4 (FFP1) and APF 10 (FFP2) disposable half masks can only be fit tested if N95 technology is employed.

It should be noted that the Fit Factor should not be used when calculating an individual’s actual exposure to hazardous substances. The Fit Factor is the result of fit testing and is valid at the time of testing only. The Assigned Protection Factor (APF) should always be used when selecting RPE for use at work.

Training Dates


Thu 28th May: FULL
Thu 25th June: FULL

Fri 29th May: FULL
Fri 12th June: FULL


Thu 4th June: FULL


Fri 29th May: FULL


Thu 30th May: FULL


We are happy to arrange on-site training courses for 3 or more delegates anywhere in the UK. Please contact us for details.