Personal care products reported to cause allergic contact dermatitis from the presence of formaldehyde need to be re-examined in light of recent chemical developments in our understanding of the film former, toluene sulfonamide formaldehyde resin, the preservatives diazolidinyl urea and imidazolidinyl urea, and formalin. This paper will elucidate these chemistries as well as review how formaldehyde is used in personal care products in raw materials and formaldehyde donor preservatives.