Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles (PubMed:1417752). Has a sulfatase activity (PubMed:1417752). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Homodimer. Expressed at low levels in liver. In lung, expressed at low levels in ciliated bronchiolar cells, alveolar macrophages and alveolar type II cells. Belongs to the GST superfamily. Theta family.