What exactly is a HEPA filter?
The HEPA (High Efficiency Particle Arresting) filter was developed by the US Atomic Energy Commission to filter out sub-micron particles. All True Medical HEPA is laser-tested and must remove a minimum of 99.97% of all particulate matter greater than 0.3 microns in size. A human hair is about 300 times too large to penetrate a HEPA filter.