Respirator Fit Check

Although negative pressure respirators are an accepted way to reduce exposure to airborne contaminants, engineering controls should always be your first choice. Sometimes strategies such as adequate ventilation can reduce contaminants to levels where personal protection is not required. However, if you do choose this equipment, you must be certain of two things: Have you selected the proper respirator with the correct filtering media, and does it fit properly?

No amount of training or respiratory equipment will provide the protection you need unless a good seal is made. Prior to entering a contaminated atmosphere, you must perform a test to guarantee that you have a proper seal between your face and the face piece of the respirator. A "Fit Check" provides proof that an adequate seal exists. The fit check consists of both a negative and a positive pressure seal test.

This test can be conducted by following the manufacturers' instructions or by using the guidelines listed below. NOTE: These test are easily performed on respirators that are equipped with valves but may be difficult to do on "valve less" respirators and disposable respirators.

Negative Pressure Test:

· Don the respirator according to the manufacturer's instructions.

· Cover and seal the filter cartridge(s) using the palm of your hand(s).

· Gently inhale through the respirator and hold your breath approximately 10 seconds.

· The respirator should collapse slightly. Check, feel and listen for leaks around the face piece.

· If there are no leaks, it can be reasonably assumed that there is a good seal and the respirator is not leaking.

Positive Pressure Test:

· Cover the exhalation valve with the palm of your hand.

· Gently exhale but do not break the seal around the face piece.

· The respirator should expand slightly with a slight positive pressure increase in the face piece.

· If there are no leaks and no loss of pressure, it can be reasonably assumed that there is a good seal.

The only way to take full advantage of any negative pressure respirator you use is to be sure that you have a good facial seal. Conducting a fit check prior to entering a contaminated atmosphere provides that assurance. It only takes a minute, and it can save your life.