Shortened term for surface active agent. Surfactants degrease and emulsify oils and fats and suspend soil, allowing them to be washed away, as laundry products do. We sometimes refer to these substance as “detergent cleansing agents.” Surfactants and detergent cleansing agents are often used interchangeably by chemists and researchers (Sources: Food and Drug Administration, Office of Cosmetics and Colors Fact Sheet, February 3, 1995, www.fda.gov; Dermatology, 1995, volume 191, number 4, pages 276–280; Tenside, Surfactants, Detergents, 1997, volume 34, number 3, pages 156–168; and http://surfactants.net). Surfactants are used in most forms of cleansers and many of them are considered gentle and effective for most skin types. There are several types of surfactants that can be sensitizing, drying, and irritating for skin. When those are the main ingredients in a facial cleanser, body wash, or shampoo, they should be avoided. Chief among the drying, irritating surfactants is sodium lauryl sulfate. The similar-sounding ingredient sodium laureth sulfate is fine.