I’ve been alerted to a recent NPR story and its FDA reference. Readers and listeners should make the distinction between tattoo inks and permanent makeup pigments–their formulas are very different; beyond that, I can’t comment on tattoo inks. As others have pointed out, the same color compounds that are used in permanent makeup pigments are the ones used in food, which we ingest in far greater quantities, and prescription drugs. They are approved for these uses, as well as in topical makeups that are applied every day. To these are added either alcohol or distilled water (and sometimes glycerin), as vehicles for the pigments.
In answer to the question of pigment and MRI safety, I am not aware of any actual cases of MRI difficulties, and I quote from my professional organization’s website (www.spcp.org):
” According to Dr. Frank Shellock of Tower Imaging in Los Angeles, CA, a top expert in MRI safety, [out of the thousands who have had permanent makeup applied], only a handful of people have reported minor problems around the eye area and no problems around the lip or brow area. … Test studies have confirmed that the ‘iron’ particles in pigment are too microscopic to react as true metal pieces but rather are more accurately compared with ‘metals’ which already exist microscopically in the body.”