Quantification of p‐phenylenediamine and 2‐hydroxy‐1,4‐naphthoquinone in henna tattoos

Abstract

Very few studies are available in which the components of henna products used by tattoo artists have been analysed. The aim of this study was to quantify the amounts of lawsone (2-hydroxy-1,4-naphthoquinone, the active ingredient in henna) and p-phenylenediamine (PPD) in products used by tattoo artists and in commercial henna preparations used as hair dyes or to create temporary tattoos. We used high-performance liquid chromatography to detect and quantify lawsone and PPD concentrations in three products used by henna tattoo artists, 11 commercially available henna preparations, and a batch of henna leaves (Lawsonia inermis). The henna leaves contained 1.85-1.87% lawsone. Only one of the three preparations used by tattoo artists contained lawsone (0.21-0.35%), and all three were adulterated with PPD (1-64%). Of the 11 commercial henna preparations analysed, nine contained lawsone (1-2%) and two contained PPD (2% and 12%). Products purporting to be henna, but that in fact contain no henna, are being offered. Moreover, these products may contain PPD, which is associated with health risks, especially severe allergic reactions.