Nitrosamines in industrial

The symposium upon which this volume is based was organized at a turning point in nitrosamine research. Almost all types of commercial products have been tested for volatile nitrosamines, and there have been a number of outstanding accomplishments of combined university-gov-emment-private industry actions to lower or eliminate volatile nitrosamines in those products found to be contaminated. However, there is still a major gap of knowledge with regard to compounds that are not amenable to analysis by gas chromatography, and this is clearly a frontier of current research. There are also many important questions regarding chemistry, mechanism of action, and relation to human disease whose answers lie in the future of research in this field. 

The complex pattern of human exposure to environmental N-nitroso compounds is summarized. Recent results are given in three areas, where a significant reduction of human exposure has been achieved after elucidation of its causes 1, N-Nitrosodimethylamine in beer. 2, Volatile N-nitrosamines in baby nipples and pacifiers and 3. occupational exposure in the rubber industry. 

Determination of Certain Nitrosamines in Municipal and Industrial Discharges using LLE and GC... 

Nitrosamines are toxic compounds as well as potent animal and human carcinogens (Patnaik, 1992). These substances occur in trace quantities in tobacco smoke, meat products, and salted fish. Some of these compounds are classified by U.S. EPA as priority pollutants in industrial wastewaters, potable waters, and hazardous wastes. These nitrosamines are listed in Table 2.16.1. Such pollutants occurring in environmental samples can be determined by U.S. EPA s analytical procedures (U.S. EPA 1990, 1992). 

The presence of A-nitrosamines in the atmosphere, workplace, food, and articles of common use should be monitored and later eliminated. Checking the presence of nitrosamines is particularly important for products intended for direct contact with food and the human body. This applies especially to rubber articles intended for infants and children (e.g., pacifiers and toys) and products used in the food industry (e.g., hoses, belts, machine parts). Despite the fact that nitrosamines in rubber products are present in very low concentrations (parts per million and lower), these compounds can threaten health. 

Fajen JM. 1980. Industrial hygiene study of workers exposed to nitrosamines. In Proceedings of the first NCI/EPA/NIOSH collaborative workshop Progress on joint environmental and occupational cancer studies. May 6-8, Rockville, MD. 

Frank CW, Berry CM. 1981. N-Nitrosamines. In Clayton GD, Clayton FE, eds. Patty s industrial hygiene and toxicology. 3rd ed. New York, NY John Wiley Sons, 3117-3133. 

A24. Ducos, P. and R. Gaudin Occupational exposure to volatile nitrosamines in the rubber industry in France CAH Notes Doc. 123 (1986) 145-150. 26A38. 

A161. Solenova, L.G., L.V. Krishosheeva, G.A. Smirnov, and A.Y. Khesina A-Nitrosamines in the air of industries producing rubber shoes and industrial rubber goods 26A176. Gig. Tr. Prof. Zabol. (1990) (6) 23-25. 

Anon., 1980, Investigations on formation and occurrence of volatile nitrosamines in Danish cheese. The Government Research Institute for Dairy Industry and The National Food Institute,... 

Emissions of nitrosamines (specifically, iV-nitrosamines) arouse particular concern owing to associated cancer risks." All secondary amines are potential precursors to N-nitrosamines and it will be apparent from considerations of the reactions both prior to cure and accompanying cure (e.g. eqns (24), (27)) that amines may be commonly encountered in vulcanized mixes and the vapours from them. Some of the amines already encountered in emissions from rubber are listed in Table 8. It should be made clear from the outset that not all the amines listed are secondary, and that primary amines are not direct precursors to AT-nitrosamines. Considerable attention has been focused on iV-nitrosamine formation within the rubber industry, and various monitoring exercises have detected such nitrosamines in both vapours and solvent extracts.In one study airborne concentrations in excess of 1 mg/m were found for dimethylnitrosamine (A/ -nitrosodimethylamine), and as high as 4-6mg/m for N-nitrosomorpholine." However, the amine is only one-half of the equation and effort has also been directed to establishing the identity... 

This compound used to be employed as an industrial solvent and was used in cutting oils. However, workers exposed to it suffered liver damage and developed jaundice, and the compound, as well as other nitrosamines, was found to be a carcinogen. A number of other nitrosamines were later found in industrial materials and as by-products of food processing and preservation. Because of their potential as carcinogens, nitrosamines are avoided in the practice of green chemistry. 

Cyclohexylamine is miscible with water, with which it forms an azeotrope (55.8% H2O) at 96.4°C, making it especially suitable for low pressure steam systems in which it acts as a protective film-former in addition to being a neutralizing amine. Nearly two-thirds of 1989 U.S. production of 5000 —6000 t/yr cyclohexylamine serviced this appHcation (69). Carbon dioxide corrosion is inhibited by deposition of nonwettable film on metal (70). In high pressure systems CHA is chemically more stable than morpholine [110-91-8] (71). A primary amine, CHA does not directiy generate nitrosamine upon nitrite exposure as does morpholine. CHA is used for corrosion inhibitor radiator alcohol solutions, also in paper- and metal-coating industries for moisture and oxidation protection. 

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