While the Internet has provided consumers with a wealth of information on a number of important issues, it also has given way to misinformation and inaccuracies about cosmetics and personal care products and their ingredients. Preservatives, for example, have come under attack and led some consumers to seek “preservative-free” products. Yet the U.S. Food and Drug Administration (FDA) states, “Cosmetics need not be sterile, however, they must not be contaminated with microorganisms that may be pathogenic, and the density of non-pathogenic microorganisms should be low. In addition, cosmetics should remain in this condition when used by consumers.”1
Because all microorganisms require water for growth, most aqueous-based, multi-use products require preservation to protect against spoilage from bacteria, yeast and fungi. Conversely, non-aqueous personal care products such as dry powders or lipsticks present a low risk for growth of microorganisms during use.2 Other types of personal care products may be inherently hostile to the growth of microorganisms due to the nature of their ingredients or the type of packaging used, which may inhibit contamination.2
Preservatives play an important role in controlling a range of microorganisms, e.g., bacteria and fungi, that may be introduced into cosmetics and other personal care products during normal use by consumers. Growth of microbes in these products, as one Personal Care Products Council video shows,3 can adversely affect consumer health and the aesthetic or functional qualities of products.4, 5 Formaldehyde-donor (FD) preservatives are one family of ingredients whose chemistry, safety, efficacy, benefits and limitations have been widely studied for the control of microbial growth in personal care products. Their properties and efficacy are reviewed here.