A new study indicates that tattoo inks could have potentially harmful ingredients in them and that many inks do not accurately explain what Americans are putting under their skin. The study, posted in the journal Analytical Chemistry, said that of 54 inks tested, 45 — or 83 percent — contained ingredients not listed on the label. “Major, unlisted adulterants include poly(ethylene glycol), propylene glycol, and higher alkanes. Many of the adulterants pose possible allergic or other health risks,” the study reported. “Taken together, the results from this study highlight the potential for a si…