What is the efficiency of the High Efficiency Particulate Air (HEPA) filter?

HEPA filters are high-efficiency filters, those have great filtration capacity. This type of air filters have the efficiency to remove at least 99.97% particles in air up to 0.3μm in diameter. HEPA filters are also called high-efficiency particulate absorber. These filters are composed of small glass fibers those holds the particles pass through it. The efficiency of HEPA filters depends upon the fiber diameter and thickness.