Monitoring of Lawsone, p-phenylenediamine and heavy metals in commercial temporary black henna tattoos sold in Turkey

SummaryBackground Henna has a very low allergic potential, and severe allergic contact dermatitis is mainly caused by p-phenylenediamine (PPD), which is added to temporary black ‘henna tattoos’, and potentially also by some heavy metals. Objective To determine the presence of, and quantify, Lawsone, PPD and heavy metal contaminants (cobalt, nickel, lead, and chromium) in commercial temporary black henna tattoo mixtures (n = 25) sold in Turkey. Methods Lawsone and PPD concentrations were analysed with high-performance liquid chromatography, and heavy metal quantification was performed with inductively coupled plasma mass spectrometry. Results PPD was found in all 25 black henna tattoo samples purchased from tattoo shops; levels varied between 3.37% and 51.6%. Lawsone was detected (0.002–88.2%) in 21 of the 25 temporary black henna tattoo samples analysed. Heavy metal contaminant levels were 0.44–3.11 ppm for Co, 1.13–2.20 ppm for Ni, 1.59–17.7 ppm for Pb, and 35.0–76.9 ppm for Cr. Conclusions Our results suggest that commercial temporary black henna mixtures containing PPD levels up to 51.6% pose a risk of contact sensitization and severe allergic contact dermatitis among users. It is important to identify both the additives and metallic contaminants of black henna tattoo products; the significance of metal contaminants has still to be assessed.