Generally speaking, the existing car air purifier (including home) on the market is mainly using HEPA filter to filter. According to the U.S. Department of Energy standards, the particle diameter of 0.3 micron particles (such as dust, pollen, bacteria, etc.), HEPA filtration effect can reach more than 99.97%.

HEPA filtration is effective and safe, but it is also helpless for harmful gases. So there are products equipped with a negative ion generator technology, the use of high voltage discharge anion to remove odor, purify the air, bring green and healthy car environment.