Ethylenethiourea

Abstract

Ethylenethiourea (ETU) is a manufacturing, processing;, and metabolic product of the ethylenebisdithiocarbamate (EBDC) fungicides. Toxicological studies indicate that .E'ru may produce goiterogenic, tumorogenic, tmd teratogenic effects in laboratory animals, raising the concern that residues may be found on. agriculturai commodities. Thin-layer chromatography, polarography, and radioisotopic methods are used for ETU ana1ysis, though electron capture or flame photometric gas-liquid chromatography are the preferred methods because of their greater sensitivity, specificity, and accuracy. ~rivatization of ETUis usually necessa:i-y prior to gas liquid. chromatography. ETU is degraded by. oxidative reactions in biological systems and by.photolytic reactions, especially in the presence of photosensitizers. Degradation products of ETU detected in photochemical, soil, and plant systems include 2wimidazolidinone (EU), 2-ilnidaZline, . 2,4-imidazolidinedione (hydantoin), tmd 3-(2-iinidazolin-2-y1)..:2-imiaaiolidinethione (Jaffe's base). Ethyleneurea, oxalic acid, glycine, and urea have been detected in animal urine. The amo1mt of E'lU residue detected in the environment depends on the amoWlt applied with the EBDC i\.ingicide, the rate of formation as a result of EBDC degradation, and the rate . of degradation. Residues of ETU have been detected in crops receiving EBDC fungicides. Levels of E'lU detected are.well below 0.1 ppm and occur primarily as surface residues.