P2 mask

This type of facemask is also known, more correctly, as a P2 respirator and is able to filter out fine particles from the air. Initially the demand in Australia was for protection against bushfire smoke but then it became part of the protective gear against the spread of the Covid-19 virus.

While it is commonly referred to as a facemask there is a difference between a mask and a respirator.  A facemask, such as a surgical facemask, will prevent large droplets generated by the wearer from reaching other people but it is no protection against fine particles coming in. The P2 respirator is the best protection against fine particles, as in the bushfire smoke, or airborne infectious diseases.  The P classification indicates that the respirator can be used against particles and oil-based aerosols, and the 2 is the rating for the size of the particles that it can block.

An equivalent type of respirator is the N95. The N classification indicates that this respirator is not designed to protect against oil-based aerosols but will filter out fine particles.