Face fit testing is the checking of respiratory protection equipment (rpe) by an accredited Fit2Fit provider to ensure it is airtight on a specific user or individual.  This is to prevent exposure to hazardous materials such as asbestos, dust particles and certain gases or vapors, which can cause chronic lung disease or cancer later in life.  Anyone wearing a tight fitting mask is legally required under COSHH regulations to have a face fit by an accredited fitter.