Different photolysis kinetics and photooxidation reactivities of neutral and anionic hydroxylated polybrominated diphenyl ethers

► Direct photolysis of anionic HO-PBDEs is faster than that of the neutral forms. ► Anionic HO-PBDEs show higher reactivities towards 1O2 and OH than the neutral forms. ► Structure-reactivity equations were built to predict the photochemical reactivities. ► Direct photolysis is the dominant phototransformation pathway.