I've used millennium and skin candy. Both are lagit brands. I've had no issues with any tattoo done with them. I used to use crazy chameleon and loved it. But I dont know what happened to them. Ive had several of my own u.v. pieces for over 9 years. No issues, and they still glow. I say to each their own. I provide the option of u.v. to clients. I , all these inks are phosphorous free. And while no ink has an FDA approval, the pigments used in these inks have been approved for permanently marking animals. While not noted for humans.... No ink is... So there ya go... Just my two cents.