Preservative Sensitization—Safety With and Safety Without

Preservatives serve the necessary purpose of preventing microbial contamination and maintaining cosmetic product integrity and safety; however, there are limitations to their use. Preservatives, including formaldehyde (FA) and formaldehyde releasers (FRPs), isothiazolinones, iodopropynyl butylcarbamate (IPBC), methyldibromoglutaronitrile (MDBGN), parabens, thimerosal, and triclosan, are a leading cause of allergic and irritant contact dermatitis, and there is increasing evidence that some may even cause toxic effects including endocrinological effects. One approach to minimizing these effects is the use of self-preserving or preservative-free cosmetic formulations. This article will outline these preservatives, their role in cosmetics, scientific evidence for allergy and toxic effects, and potential alternatives.