FS05.3 New characterization and chemistry of Germall 115 and Germall II

Abstract

Germall 115 and Germall II are well known cosmetic preservatives, widely used as such since the early 1970’s and 1980’s, respectively. This investigation reveals that they have mistakenly been regarded as pure chemical entities with specific structures by the majority of the chemical society. In fact Germall 115 and Germall II both consist of complex mixtures of numerous and fast degradable allantoin‐formaldehyde condensation products and may not even contain the conventionally assigned chemical structures of imidazolidinyl urea (Germall 115) and diazolidinyl urea (Germall II). Equilibrium between different structures may be formed in different cosmetic formulations/test materials. This may have led to the discrepancies in the literature: Are the Germalls themselves sensitizers or are the allergic reactions caused by formaldehyde release? The identification and structure assignment of (4‐hydroxymethyl‐2,5‐dioxo‐imidazolidin‐4‐yl)‐urea (HU) will be presented, as it is the major and chemically stable degradation product of both Diazolidinyl urea and Imidazolidinyl urea. A guinea pig maximization test has been performed to determine the potential of HU to induce delayed contact hypersensibility in guinea pigs. Separate chemically stable TRUE Test patches containing the mixtures have shown clinical efficacy.