Generally, the deodorizing effect of the air purifier is related to the negative ion concentration, and the higher the negative ion concentration, the more obvious the deodorizing effect. But ozone and negative ions are always produced together. Ozone is a non-toxic safe gas, but concentrations above 1.5 ppm will irritate the human respiratory system. Therefore, when choosing an air purifier with negative ion function, try to choose a brand that specializes in air purifiers. After years of research, the technology will be more mature. In addition to the partial odor of the activated carbon filter in the air purifier, the negative ion function is the main force of deodorization.