Respirator Fit Testing

Before initial use of a respirator and at least once a year as per WorkSafeBC regulation 8.40.

Whenever there is a change or replacement in respirator facepiece, including the brand, model, and size.

Whenever changes to the user’s physical condition could affect the respirator fit.

Other personal protective equipment that is to be worn at the same time as a respirator and which could interfere with the respirator fit must be worn during the fit test.

Before each use of a respirator which requires an effective seal with the face for proper functioning, a worker must perform a positive or negative pressure user seal check in accordance with CSA Standard CAN/CSA-Z94.4.02, Selection, Use, and Care of Respirators (2) Subsection (1) does not apply to the emergency use of an escape respirator.

Yes. The fit test is specific to each respirator.

No. A fit test only qualifies the user to put on the specific brand/make/model of respirator with which an acceptable fit testing result was achieved. Users should only wear the specific brand, model, and size respirator(s) that they wore during successful fit tests.

(Note: respirator sizing is variable and not standardized across models or brands. For example a medium in one model may not offer the same fit as a different manufacturer’s medium model.)

A user seal check is a procedure conducted by the respirator wearer to determine if the respirator is properly seated to the face. The user seal check can be either a positive pressure or negative pressure check, which are generally performed as follows:

• The positive pressure user seal check is where the person wearing the respirator exhales gently while blocking the paths for exhaled breath to exit the facepiece.
• A successful check is when the facepiece is slightly pressurized before increased pressure causes outward leakage.
• The negative pressure user seal check is where the person wearing the respirator inhales sharply while blocking the paths for inhaled breath to enter the facepiece.
• A successful check is when the facepiece collapses slightly under the negative pressure that is created with this procedure.
• A user seal check is sometimes referred to as a fit check.
• A user seal check should be completed each time the respirator is put on (donned).
• It is only applicable when a respirator has already been successfully fit tested on the individual.

The following positive and negative user seal check procedures for filtering facepiece respirators are provided as examples of how to perform these procedures.

Positive pressure check – Once the particulate respirator is properly put on (donned), your hands over the facepiece, covering as much surface area as possible. Exhale gently into the facepiece. The face fit is considered satisfactory if a slight positive pressure is being built up inside the facepiece without any evidence of outward leakage of air at the seal. Examples of such evidence would be the feeling of air trickling onto your face along the seal of the facepiece, fogging of your glasses, or a lack of pressure being built up inside the facepiece.

If the particulate respirator has an exhalation valve, then performing a positive pressure check may be impossible. If so, then do a negative pressure check.

Negative pressure check – Negative pressure seal checks are conducted on particulate respirators that have exhalation valves. To conduct a negative pressure user seal check, cover the filter surface with your hands as much as possible and then inhale. The facepiece should collapse on your face and you should not feel air passing between your face and the facepiece.

Once a fit test has been done to determine the best model and size of respirator for a particular user, a user seal check should be done by the user every time the respirator is to be worn to ensure an adequate seal is achieved.

Respirators can be purchased from Gilbert Supply Co. located in Vernon, BC.