1,3-Benzenedisulfonic acid, 4,5-dihydroxy- (9CI) 149-45-1 149-46-2 3,5-Disulfopyrocatechol 4,5-Dihydroxy-1,3-benzenedisulfonic acid 4,5-Dihydroxybenzene-1,3-disulphonic acid Catechol-3,5-disulfonic acid EINECS 205-742-0 Pyrocatechol-3,5-disulfonic acid Tiron free acid m-Benzenedisulfonic acid, 4,5-dihydroxy-