N-エチルチオ尿素

Based upon an experimental value of -0.21 for log Kow(1), the Koc for N-ethylthiourea can be estimated to be 18 from a linear regression-derived equation(2,SRC). This estimated Koc suggests that N-ethylthiourea will be highly mobile in soil(3,SRC).

In the manufacture of rubber, irritant contact dermatitis may occur from a variety of acids, alkalies, detergents, and solvents used in the process. Allergic contact dermatitis occurs not infrequently and is almost always due to an organic accelerator or antioxidant. While the list of potential sensitizing accelerators and antioxidants is enormous, common allergens include ... thioureas. /Thioureas/

Since N-ethylthiourea can be used as a corrosion inhibitor for metal, as a bactericide, as a photographic chemical agent and as a chemical intermediate(1), release to the environment may occur during waste disposal from its production and use(SRC).

The Henry's Law constant for N-ethylthiourea can be estimated to be approximately 2.35X10-8 atm-cu m/mole at 25 °C using a chemical structure estimation method(1,SRC). Based on this value and the volatility characteristics associated with Henry's Law constant(2), N-ethylthiourea should be less volatile than water.

In tests to assess the environmental hazard of chemicals, thiourea was found to be stable towards hydrolysis and photolysis(1). Therefore, hydrolysis and photolysis of N-ethylthiourea, which is structurally similar to thiourea, may not be important(SRC). Based on an estimation method, the rate constant for the reaction of vapor-phase N-ethylthiourea with hydroxyl radicals has been estimated to be 9.96X10-11 cu cm/molecule-sec(2,SRC). Assuming the daily average concn of hydroxyl radicals in the atmosphere of 5X10+5/cu cm(3), the half-life for this reaction has been estimated to be 4 hrs(SRC).

Since N-ethylthiourea has been patented to be useful as a corrosion inhibitor for metal, as a bactericide, as a photographic chemical agent and as a chemical intermediate(1), the probable routes of exposure are inhalation of dust and skin absorption of the compound during its production, use and disposal(SRC).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 1,031 workers are potentially exposed to N-ethylthiourea in the USA(1).

The release of N-ethylthiourea in the environment is expected to occur during waste disposal from its production and use. If released to soil, biodegradation of N-ethylthiourea may be an important removal process. Because of the estimated low Koc value in soil, N-ethylthiourea may rapidly leach from soil. The volatilization of N-ethylthiourea from moist soil is not expected to be an important removal process. Neither photolysis nor hydrolysis are expected to be important in water. Based on its low Koc value, the compound will not remain adsorbed to particulate matter and sediment in water, but instead will be present in the water column. Based on its estimated low values for Henry's Law constant and bioconcentration factor, neither volatilization from water nor bioconcentration in aquatic organisms would be important for N-ethylthiourea. In the atmosphere, vapor phase N-ethylthiourea would be removed from the atmosphere with an estimated half-life of 4 hr due to reaction with hydroxyl radicals. The primary removal processes for particulate N-ethylthiourea from the atmosphere may be wet and dry deposition. Worker exposure to N-ethylthiourea is likely to occur both by dermal and inhalation routes during the production, use and disposal of the compound. (SRC)