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.