Detergent and skin irritation

Abstract

U ntil the late 19th century, the only man-made surfactant was soap. Soaps are the sodium or potassium salts of fatty acids or similar products formed by the saponification or neutralization of fats or oils with organic or inorganic bases. Soaps are less useful, however, in hard water, which is high in content of multivalent ions, such as calcium and magnesium. Despite this, its critical shortage in Germany after World War I provided an incentive for the development of synthetic soap substitutes, detergents.’ A synthetic process for sodium lauryl sulfate was described in Germany 6 decades ago.2 The term “deterge” derived from the Latin detergere, meaning to wipe off; the term “detergent,” which has existed at least since 1676, is used to mean a cleansing agent. Nowadays, a detergent includes almost any surface-active agent (surfactant) that concentrates at oilwater interfaces and holds cleansing as well as emulsifying properties. Since the late 194Os, synthetic surfactants have been used in ever-growing proportions in consumer and industrial cleaning formulations; among the various classes, anionic surfactants have been used most frequently.3 Recent figures for the United States indicate that anionic surfactants represent between 43 and 67% of the active ingredients in household, personal care, and industrial formulations. In 1992, total surfactant use was 2.3 billion kg, of which anionic surfactants made up 53%.3