Volatile Corrosion Inhibitors and Boiler Water Additives: Potential for Nitrosamine Formation. Task III. Chemical Technology and Economics in Environmental Perspectives

摘要

Study investigated volatile corrosion inhibitors (VCIs) and the use of amines as boiler water additives. The major VCI's are dicyclohexylammonium nitrite (Dichan), 'nonnitrite' Dichan substitutes, and benzotriazole. The present market is about 310,000 kg/year; over 90% of the use is in the preparation of impregnated paper and other wrapping materials. Dichan can be converted to the corresponding nitrosamine; commercial products can contain up to 1 ppm of the nitrosamine. Nonnitrite subsitutes are less likely to be converted to nitrosamines but can likely be readily nitrosated under environmental conditions. Benzotriazole is likely to be environmentally stable and not converted to the corresponding nitrosamine. Population exposure to VCI's is large since it is estimated that over 20 million individual items are wrapped in VCI impregnated paper. Two cases of nitrosamine detection at levels of 100 and 90 ppm in VCI wrapping paper have been reported. A number of amines are employed for treating boiler water. The total market in 1978 was estimated to be 9,000 to 10,300 metric tons. The two most widely used neutralizing amines are cyclohexylamine and morpholine; octadecylamine is the most common film-forming amine. There is no experimental evidence to indicate whether or not nitrosamines are formed in boilers as a result of the addition of these amines.