LOS ANGELES - The Food, Drug and Cosmetic Act's bar on private enforcement preempts California residents' unfair competition law (UCL) claims involving the addition of the allegedly unapproved drug hydrofluosilicic acid (HFSA) to the water supply, a federal judge held April 10 (Debra Foli, et al. v. The Metropolitan Water District of Southern California, et al., No. 11-1765, S.D. Calif.; 2012 U.S. Dist. LEXIS 50272).