Since tattoos became overwhelmingly fashionable worldwide, the demand for removal has proportionally increased, Nd:YAG Q-switch laser being the most commonly used tool for the purpose. In this framework we investigated the composition and products of laser treatment of green tattoo ink, the Green Concentrate from Eternal. The ink characterization has been carried out by IR, UV-Vis, EDX spectroscopies, and SEM imaging. It revealed the presence of the pigment PG7, rather than PG36 as reported on the bottle label, along with non-fully halogenated analogues. The morphology is an extended sheath with embedded grains. Subsequent laser treatments were performed on both dried and extracted inks, dispersed either in water or in propan-2-ol, chosen for their different polarities, as it is the case in the skin layers. The products were analyzed by gas chromatography-mass spectrometry, UV-Vis spectroscopy, SEM imaging, and dynamic light scattering. The outcome is a complex fragmentation pattern that depends both on the solvent and on the initial aggregation state. The fragment compounds are toxic at various degrees according to the Classification Labelling and Packaging regulations. Several shapes of aggregates are produced as an effect of both downsizing and re-aggregation, with potentially harmful aspect ratios.

Within the framework of a nationwide project to boost students' enrollment in scientific disciplines in Italy, a multilevel science project was designed with a focus on the chemistry of tattoo inks, offering immediate connection with 16−18 year-old high school students. The approach takes into account time constraints, since all sessions have a maximum span of 8 h, and the heterogeneity of the audience, made up of students without background restrictions. Tattoos are perceived as a form of body art and can be conveniently used as the "A" in the STEAM (science, technology, engineering, art, and mathematics) methodology. The project involved active lectures and guided inquiry into the simple chemical concepts related to tattoo inks, addressed in practical units with multioutcome experiments and comparative instrumental analysis. The connections with correlated issues, such as norms regarding tattoo ink composition and verification, were also discussed. The efficacy of the tattoo ink Scientific Degree Plan experience was then evaluated through two types of surveys: one on the enjoyment of the plan and the other on mastery of the chemical concepts at the end of the experience.