3M had given us some brief Q&A to emphasise the importance of, and the differences between, fit checking and fit testing, enabling you and your employees to safely use respirators while knowing how responsibility is shared.

What types of respirators need to be fit tested and fit checked?
Any tight-fitting Respiratory Protective Equipment (RPE) – disposable respirators, reusable half masks and reusable full face masks. All employees that use tight-fitting RPE as a control measure must be fit tested.

Why is respiratory fit important?
Employees working in hazardous environments need protection from airborne contaminants, which can cause serious physical ailments. When a tight-fitting respirator is used the fit is critical to enable protection and comfort for the wearer. An inadequate seal between the respirator and the wearer’s face can result in contaminated air entering the mask and therefore being breathed in by the wearer.

What factors affect fit?
Face shape and size, facial hair, eyewear (both prescription and safety glasses) and jewellery should all be considered.

What is the difference between a fit test and a fit check?

Fit test: This is a test that must be conducted every time a new model of tight-fitting RPE is selected. It should be conducted by a competent person appointed by the employer. This test is the employer’s responsibility and is a requirement of COSHH.

Fit check: This is a check that should be carried out by the employee/wearer of the device each time that they put it on, even if this occurs several times per day. Although not a formal requirement like fit testing, a fit check is a good practice that gives an indication that the respirator is positioned correctly. The responsibility of a fit check remains with the employee.

What are the positive and negative pressure fit checks?
Positive pressure fit checks involve the respirators being ‘over-inflated’ by exhaled air to help identify leaks. Negative pressure fit checks involve the respirator being sucked onto the face to help identify leaks. The method varies by model and will be described in the user instructions.

Positive pressure checks generally involve the exhalation valve being sealed before exhaling into the respiratory device. If a slight positive pressure can build up inside the facepiece without any obvious leakage of air, then it is considered a satisfactory fit. Likewise, to check negative pressure, a wearer can close the inlet valve and inhale. If there is no obvious inward leakage of air then this is also considered a satisfactory fit.

Fit Test vs Fit Check

Disclaimer: The information provided through Greenham Pulse is for general guidance only and is not legal advice. Greenham Pulse is not a substitute for Health and Safety consultancy. You should seek independent advice about any legal matter.