How to properly adjust a half-mask

How to properly adjust a half-mask


The fit of a half-mask respirator must respect some important notions to ensure the optimal protection of the user. 

We’ll walk you through the steps you need to take to get there.

  1. First, lengthen the head harness straps. This allows you to be comfortable when you put it on your head.
  2. Take the respirator in your hand, nasal side up. Then, place the respirator over your mouth.
  3. You can then slip the head harness over the back of your head.
  4. The bottom straps can then be attached at the nape of your neck.
  5. To adjust your respirator properly, you’ll need to pull on the top straps on either side of your head. This will allow you to adjust the head harness for comfort.
  6. Do the same for the lower straps.
  7. To ensure a good seal between the mask and your face, it’s crucial to perform a positive and negative pressure test. The presence of a beard or any other type of facial hair under the seal of a mask can lead to leaks, reducing the protection offered to the wearer.        
    • The negative pressure test: place both hands over the two holes/filters and inhale. If the mask sticks to your face, you have a good seal.    
    • The positive pressure test: use the palm of your hand to close the valve at the bottom of the mask, then try to exhale. If you feel air coming out of the mask, it’s a sign of a poor seal.     

If pressure tests are inconclusive, reposition the mask on your face or readjust the straps to prevent leaks.

It’s important to follow these crucial steps before entering a contaminated area that could affect your health if your respirator isn’t sufficiently airtight.

We can help you with your fit testing!

At SPI Health and Safety, we can perform qualitative and quantitative fit tests on your respiratory protection equipment in just 20-30 minutes.

We’ll even train you to carry out your own fit tests!

Find out more about our training courses

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