Basic safety testing for tattoo ingredients

Currently, no mandatory safety testings exist for tattoo ink ingredients exist. For many ingredients and impurities, data on toxic properties exist due to their use in other applications.

For most pigments, only very limited information on their safety is available. They are often impure and manufactured with additional ingredients, like resins, polymers or surfactants.

Which data would you consider necessary for a minimum safety evaluation? A lot of safety data (carcinogenicity, reprotoxicity) would require animal testing - would you approve to carry out animal testing for tattoo ingredients?