The most commonly used liquids are alcohol, propylene glycol, polyethylene glycol, and plain water. Powders may be incorporated into protective creams, lotions, and ointments. Gels are water-based substances thickened without oil or fat. The skin doesn't absorb gels as well as it absorbs preparations containing oil or fat. The principal cleansing agents are soaps, detergents, and solvents.
Soap is the most popular cleanser, but synthetic detergents are used as well.
Because baby shampoos are excellent cleansing agents and are usually gentle to the skin, they're good for cleansing wounds, cuts, and abrasions. Also, people with psoriasis, eczema, and other scaling diseases can use baby shampoos to wash away dead skin. Many chemicals are added to cleansing agents. For example, antidandruff shampoos and lotions may contain zinc dipyrithione, selenium sulfide, or tar extracts to help treat flaking skin. Many different kinds of preparations help protect the skin.