There are two main criteria for choosing an effective air pollution mask:
1) High filtration efficiency against the most hazardous air pollutants (PM2.5)
2) An airtight fit to ensure that air does not leak around the sides.
1) High filtration efficiency against hazardous air pollutants (PM2.5)
Particulate matter is the most widespread and hazardous air pollutant affecting human health around the world. It it is important to choose a mask with a high filtration efficiency to protect against particulate matter, especially PM2.5 or fine particulate matters. PM2.5 is microscopic, less than < 2.5 microns in diameter and able to penetrate deep into the human body and even bloodstream, causing a wide range of health effects and reaching almost every organ in the body.
There are a range of standards available to measure the filtration efficiency of respiratory masks. KN95, N95, and FFP2 are all widely-recognized industry standards. Certifications according to these standards indicate a filtration efficiency of at least > 95% of airborne particle pollution under standard testing conditions (94% for FFP2 masks). It is strongly recommended to choose a mask that has been tested and certified according to at least one of these standards for fine particle pollution in order to achieve sufficient protection against PM2.5.
The IQAir Mask has been certified according to both KN95 and FFP2 standards.
2) An airtight fit to prevent air leakage
It is important to check that your air pollution mask has a good seal around the face, and particularly around the nose. When wearing your mask, you should not be able to feel any air escaping around the sides when you exhale. One good test is to try wearing glasses or sunglasses above your mask. If they fog up, this suggests that too much air is escaping from your mask. Air leakage indicates that your mask is not able to effectively filter all the air which reaches your body through inhalation.