Antimicrobials or preservatives are used in all cosmetic emulsions as well as in dermatologic medications. Parabens, sorbic acid, phenolics, formaldehyde, organic mercurials, quaternary ammonium compounds, betaines, dimethoxane, and dehydroacetic acid represent the chemicals most often employed for this purpose. It is my purpose to present a comprehensive review of the relative sensitizing potential of each chemical, delineate their usage, and explore diagnostic techniques as well as proper substitution therapy. Attention is also called to the problems of the cosmetic chemist as well as to advantages and disadvantages of particular antimicrobial chemicals.
Schorr WF. Cosmetic AllergyA Comprehensive Study of the Many Groups of Chemical Antimicrobial Agents. Arch Dermatol. 1971;104(5):459-466. doi:10.1001/archderm.1971.04000230001001