Boric acid is a weak preservative, and boric acid aqueous solution is weakly acidic, which combines with amino groups in protein of bacteria to play a bacteriostatic role and has a weak inhibitory effect on bacteria and fungi. Small irritation is the biggest feature of this product. It can be used as cleaner for skin and mucous membrane damage, including acute eczema and dermatitis with massive exudation, stomatitis and pharyngolaryngitis, external auditory canal mycosis, impetigo, chronic ulcer and bedsore of lower leg, etc..