I have heard a lot of tattooists say they won't use UV pigment because it's too dangerous. The fact is, I don't know of a single tattoo pigment that is FDA-approved for human use.  I do know, however, that there are UV pigments that are FDA-approved for animal/veterinary use. Whether you consider human clients to be animals is probably your call, but states that regulate tattooing have yet to regulate pigments, in general.

UV pigments for animal use do not contain phosphorus, which is the "dangerous" part of the offending inks that most tattooists are talking about. Phosphorus pigments are "glow-in-the-dark" AND UV active, thus giving the UV-only pigments a bad name. Armed with information, the choice to use UV on your clients is up to you. Good luck!