Contact allergy to petrolatums. (II). Attempts to identify the nature of the allergens.

Using several chromatographic and spectrometric procedures, it was established that the allergens present in pharmaceutical and cosmetic petrolatums are probably polycyclic aromatic hydrocarbons. These substances are impurities, and the quantity present is largely a function of the source of the petrolatum and the purification procedures. As the aromatic portion in petrolatum is a very complex and unstable mixture of chemically-related agents, only 2 out of the several possible allergens present could be identified: they were most probably phenanthrene derivatives with molecular weights of 230 and 244.