Water is used in the formulation of virtually every type of cosmetic and personal care product. It can be found in lotions, creams, bath products, cleansing products, deodorants, makeup, moisturizers, oral hygiene products, personal cleanliness products, skin care products, shampoo, hair conditioners, shaving products, and suntan products.

Water is primarily used as a solvent in cosmetics and personal care products in which it dissolves many of the ingredients that impart skin benefits, such as conditioning agents and cleansing agents. Water also forms emulsions in which the oil and water components of the product are combined to form creams and lotions. These are sometimes referred to as oil-in-water emulsions or as water-in-oil depending on the ratios of the oil phase and water phase.