Ethylenethiourea (ETU) is a carcinogenic degradation product of major ethylene bis (dithi0carbamate) fungicides with biological activity attributed to poorly characterized oxidation products. The reaction of ETU with H202 was examined in aqueous medium at pH 5, 7, and 9 by'H NMR spectroscopy giving five principal products: sequential formation of sulfenic, sulfinic, and sulfonic acids as well as imidazoline and ethyleneurea. Maximum ...