Aslo see: http://www.toxictattooink.blogspot.com (click enter if the page opens blank)
This section is being revised and brought up to date because the FDA has responded to the "Premier" Cosmetic Ink cluster of reactions.
For tattoo there seems to have been too few incidents reported and no clusters that would cause the FDA to investigate.
Cases of allergic reactions to tattoo ink are isolated and anecdotal and do not consititute a body of evidence that would indicate a need for regulation. This I think has been reflected in the FDA position.