It is a way to check that the respirator being worn will actually offer the protection that it has been designed for. Be mindful that although respirators are designed to fit the vast majority of the adult population, along with some youths, every user has a differently sized and shaped face. Just like shoes sizes we must make the effort to capture the correct size for the individual concerned. Fit testing delivers a pass/fail result and must be carried out by an appropriately trained, competent individual. The fit tester will also offer guidance on correct fitting and use of the mask.