Understanding Fit

Understanding Fit

There is more to a respirator than filtration.

April 30, 2021 | Published by O2

After a full year of face coverings, disinfecting, social distancing and stay home orders, we know that wearing a mask is an important way to prevent the spread of SARs-Cov-2. With new, highly transmissible strains of the virus emerging, what additional steps can we take to help prevent getting and spreading COVID-19? We’ve already talked about how double masking can make a difference in respiratory protection. Another important feature to look for in a face covering is its ability to form a seal around your nose and mouth.

When face coverings don’t fit snugly against the sides of the face and have gaps there is an exposure to what is being both inhaled and exhaled. Air with respiratory droplets containing the virus can leak in and out around the edges of the mask. This is why testing the fit of your mask or respirator is key to prevent air leakage and virus transmission.

Qualitative and Quantitative Fit Tests

You may have heard of the two different fit tests; “qualitative” fit testing and “quantitative” fit testing. Both test the effectiveness of a mask’s fit. A qualitative fit test is based on the wearer’s ability to detect a small amount of harmless solution, by smell or taste. The test is scored only on a pass/fail basis.

 A quantitative fit test uses a specialized instrument to objectively measure the amount of leakage from the tested mask or respirator. The machine takes measurements of the level of particles inside the mask compared to the air outside of the mask. 

Understanding the fit of your mask

While both of these tests require a certified fit tester and special instruments, you can still evaluate the effectiveness of your mask at home. A self-evaluation can be performed by cupping your hands around the outside edges of the mask. Exhale forcefully and feel for your breath flowing from the area near your eyes or from the sides of the mask. If you feel minimal air coming from these areas and warm air coming through the front of the mask, the mask is a good fit.

Air will always follow the path of least resistance, by feeling breath with your hands, you can identify gaps or leaks and correct them. Here are a few tips to improve the fit of your mask or respirator.

  1. Nose Wires; either sew in a small wire or look for a mask with nose wire included. After donning the mask with the ear loop straps mold the nose strip as tight as possible to the contours of your face.
  2. Double masking: Wearing a second mask over top can improve fit by pressing the inner mask closer to the face, thereby reducing the amount of air that leaks around the edges of the masks.
  3. Shave. Facial hair styles that cross the seal of the mask have the potential to create leaks. Having stubble can either pierce the mask or create an uneven surface — both allowing the possibility of a leak. Shaving is a personal choice however, some are choosing to remove facial hair to improve the seal of their masks. 

Respirators like the O2 Curve, offer a unique medical grade silicone for a superior seal. The silicone flexes to the conforms of the wearers face to ensure a seal is maintained, even when talking. These respirators seal above the chin, thereby reducing interference with facial hair and results in respiratory protection that is more compatible with facial hair. Click here to watch a video on O2’s medical advisor explaining how to fit test with the O2 Curve.


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