Moldex bitrex fit testing kit the approved code of practices supporting coshh car and claw stipulate that tight fitting rpe respiratory protective equipment must be fit tested as part of the selection process this is to ensure that the selected rpe has the potential to provide adequate protection for the wearer there are two main reasons for doing bitrex testing firstly to make sure that the respirator itself is suited for the wearers particular face shape secondly to make sure that the respirat