Afro woman wearing a half mask for respiratory protection

How does a respirator work?

Commonly known as a gas mask, a respirator is an air filtration system designed to protect your respiratory system and face from chemical particles and contaminants in the air.

In our opinion, the most important way to understand how a gas mask works is to study the mechanism of its air filter.

Is the respirator like any other mask?

A respirator has two features that prevent us from inhaling potentially toxic contaminants in the air. These are barriers in the filter on the front (full face mask) or on the sides of the mask (half mask):

  • The first is a particulate filter that removes any bacteria present in the inhaled air. There is essentially no chemistry involved here, just a physical barrier that forms a field between the toxins and the face. When a particle is inhaled, it hits the filter fibres and becomes entangled before it has a chance to reach the nose or mouth and travel down to the lungs.
  • The second element is based on a chemical process called adsorption, and removes toxic and chemical molecules such as gases from solvents. Through adsorption, a solid can trap particles on its surface, in the same way that a cigarette filter reduces the amount of toxins inhaled by a smoker.
Ethis Crea | Respiratory protection masks

To filter out harmful chemicals, most gas mask filters are made of activated charcoal or oxidised. When charcoal is activated by oxygen, it becomes torn with thousands of absorbent holes in each molecular structure. Any toxins that pass through the charcoal attach to these holes and can no longer enter the gas mask.

How effective is a respirator?

For the full face mask, a visor goes over the head and creates a tight seal with the face. Sometimes people don't put it on properly and gas can seep through the cracks. Many gases can also affect the skin. Even if your lungs are protected by a gas maskyour skin is not.

The protection of a respirator is therefore limited to the protection of your respiratory system and your eyes if it is complete.

Can a filter become blocked?

It is a delicate compromise between creating an effective filter that captures 99.99 % of toxic particles and leaving enough open pores to breathe. Gas masks are only meant to be worn for a short time before the filter clogs and compromises its effectiveness.

How long can you wear a respirator?

Masks are not designed for a long life. You can probably wear a gas mask for three or four hours before you have to change the filter. You must be trained to put on and take off the mask, as changing the filter may briefly expose you to particles and chemicals in the air.