Catalyzes the glutathione dependent oxygenation of dichloroacetic acid to glyoxylic acid in vitro. Possesses low glutathione thioltransferase activity toward 4-hydroxynonenal (4-HNE). Has no glutathione thioltransferase activity with adrenochrome, phenethyl isothiocyanate (PEITC), 5-hydroperoxyeicosatetraenoic acid ((5S)-HpETE), prostaglandin A2 (PGA2) or 2-hydroxyethyldisulfide (HED)