Analytical survey of tattoo inks – a chemical and legal perspective with focus on sensitizing substances
Background: Tattoo inks have been reported to elicit allergic contact dermatitis. Objectives: To investigate the labels and the contents of metals and pigments in tattoo inks, considering restrictions within the European Union. Methods: 73 tattoo inks currently available on the market, either bought or donated (already used), were investigated for trace metals and pigments by inductively coupled plasma mass spectrometry and by matrix assisted laser desorption/ionization time of flight tandem mass spectrometry. Results: 93% of the bought tattoo inks violated European legal requirements on labeling. 50% of the tattoo inks declared at least one pigment ingredient wrongly. 61% inks contained pigments of concern, especially for red inks. Iron, aluminium, titanium, and copper (most in green/blue inks) were the main metals detected in the inks. The level of metal impurities was only in a few cases exceeding current restriction limits. Total chromium (0.35-139 µg/g) and nickel (0.1-41 µg/g) were found in almost all samples. The levels of iron, chromium, manganese, cobalt, nickel, zinc, lead, and arsenic were found to significantly covary. Conclusions: It is important for tattoo ink manufacturers to follow the regulations and decrease nickel and chromium impurities, to prevent contact allergy and toxic reactions among the users. ; QC 20211124