They are used to adsorb harmful aerosols such as dust, smoke, mist droplets, toxic gases and toxic vapors and prevent them from being inhaled by humans.
A na-eji ha adsorb aerosols na-emerụ ahụ, gụnyere uzuzu, anwụrụ ọkụ, nsị mmiri, gas na-egbu egbu na vapors na-egbu egbu, site na ihe nzacha ahụ, na-egbochi ha ịbanye na mmadụ.