Catechol; 1,2-benzenediol; Ortho-benzenediol; 1,2-benzene diol; Catechin; C.i. 76500; C.i. oxidation base 26; 1,2-dihydroxybenzene; Ortho-dihydroxybenzene; Ortho-dioxybenzene; Ortho-hydroquinone; 2-hydroxyphenol; Ortho-hydroxyphenol; Oxyphenic acid; Ortho-phenylenediol; Pyrocatechin; Pyrocatechine; Pyrocatechol; Durafur developer c; Fouramine pch; Fourrine 68; Pelagol grey c.