Oxybenzone can become chlorinated in swimming pools because of the chlorine in the water. Chlorine also oxidizes oxybenzone quite well. There are three major products of the chlorination of oxybenzone.
Products of chlorination of oxybenzone. Source: Chlorination of oxybenzone: Kinetics, transformation, disinfection byproducts formation, and genotoxicity changes (Chemosphere 154 (2016) 521-527)