Analytical survey of N-nitroso contaminants in pesticide products

1. Levels of N-nitroso dialkylamines in dinitroaniline derivatives were high (up to 153 mg/kg) in the past, but have been decreased considerably in current production, due to process changes. 2. Butralin and pendimethalin contain significant amounts of N-nitroso parent compounds. 3. Most dimethylamine salts of phenoxyalkanoic acids presently contain low or non-detectable levels of NDMA. 4. Quaternary ammonium compounds contain NDMA levels up to 16.8 mg/kg. 5. Two morpholine derivatives appear to contain N-nitrosomorpholine. 6. The triethanolamine salt of dinoseb contains over 200 mg/kg N-nitrosodiethanolamine. 7. A large number of amides, carbamates, organophosphates, triazines, urea derivatives and miscellaneous nitrogen-containing pesticides do not contain N-nitrosamines above 1 mg/kg. 8. Most N-nitroso contaminants in pesticides can be avoided by simple process changes and the elimination of nitrite salts in the formulation.