Phase response analysis of light-perturbed closed and aging Ru-catalyzed Belousov-Zhabotinsky (BZ) reactions with malonic, methyl-, ethyl-, butyl-, and phenylmalonic acids as organic substrates suggests two major responses of the light-perturbed Ru-catalyzed BZ system. One is the photoproduction of bromous acid (HBrO2) in the beginning of the reaction when little bromoorganic species are present, while another response is the photoproduction of bromide ions in the presence of bromomalonic acid or bromomalonic acid derivatives. From this analysis the light-induced production of bromide ions directly from bromate can be excluded. The experimentally observed phase response curves agree well with calculations performed with the Oregonator model. An oxidative quenching mechanism for the photoproduction of bromide is suggested. Interestingly, during illumination of the Ru(II)/MA subsystem, i.e., in the absence of BrMA and bromate, the oxidative quenching does also occur.