Rubber products, nitrosamine contamination

The nitrosamine contamination of rubber products originates from amine-containing accelerators and... 

Migration of nitrosamines into consumer products can occur via direct contact of materials such as waxed containers, elastic and rubber etc.81. Morpholine is used extensively as an industrial solvent for wax formulations. The wax formulations are used for coating fruits and vegetables to prevent moisture loss and increase shelf-life of the products. Paper and cardboard packed with morpholine was also found to give rise to NDMA, as these packaging materials were found to be contaminated with NDMA as well. Besides this, rubber products also provided a migratory source for both nitrosamines and nitros-able amine precursors, as trace levels of NDEA and TV-nitrosodibutylamine (NDBA) have been reported in cured meats with amine-based accelerators in the rubber nettings82. 

A-Nitrosamines in rubber products are by-products of the reactions taking place during the vulcanization of rubber mixtures [80]. They are formed from some chemical compounds such as secondary amines (accelerators, antioxidants) via nitrosation by nitrogen oxides present in the surrounding air. These reactions occur inside the rubber product and on its surface. The resulting A-nitrosamines from the interior of the rubber can diffuse to the surface of the article, and then to the environment or media in which the product is used. A-Nitrosamines can also be incorporated in the rubber mixture by contamination of raw materials during preparation. 

N-Nitroso compounds occur in many operations in the rubber industry. Some nitrosamines (nitrosodiphenylamine, N-N-dinitrosopentamethylenetetramine, polymerized N-nitroso 2,2,4-trimethyl-l,2-dihydroquinoline and N-methyl-N-4-dinitroso aniline) are used as organic accelerators and antioxidants in the production of rubber and often the products are found to be contaminated with such compounds [19]. 

Uses/Sources. Research chemical impurity in herbicides treflan, isopropalin, and triflu-ralin contaminant in wastewater from chemical factories and production of cheese and brandy and other liquors. AT-nitrosamines are frequently produced during rubber processing and may be airborne in the workplace. 

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