In vitro quantitative chemical analysis of tattoo pigments.

BACKGROUND The composition of cosmetic tattoos might prove relevant to their treatment by high-powered lasers. OBJECTIVES To test the accuracy and completeness of information supplied by the tattoo ink manufacturers and to perform an elemental assay of tattoo pigments using scanning electron microscopy with energy-dispersive x-ray analysis. DESIGN Samples of 30 tattoo inks were examined using "standardless" energy-dispersive spectrometry. This technique uses quantitative electron x-ray microanalysis. The technique reliably identifies all elements with the exception of those elements with atomic numbers less than 11. SETTING A major national referral laboratory for microscopic examination and biochemical analysis of tissue. These results were compared with ink compositions compiled from manufacturer-supplied material safety data sheets. MAIN OUTCOME MEASURES (1) The percentage of any given element in whole tattoo pigments. (2) The presence or absence of elements and/or compounds as recorded in material safety data sheets supplied by the tattoo ink manufacturers. RESULTS Of the 30 tattoo inks studied, the most commonly identified elements were aluminum (87% of the pigments), oxygen (73% of the pigments), titanium (67% of the pigments), and carbon (67% of the pigments). The relative contribution of elements to the tattoo ink compositions was highly variable between different compounds. Overall, the manufacturer-supplied data sheets were consistent with the elemental analysis, but there were important exceptions. CONCLUSION The composition of elements in tattoo inks varies greatly, even among like-colored pigments. Knowledge of the chemical composition of popular tattoo inks might aid the clinician in effective laser removal.