Nitrosamines hazards

Inhibition of a nitrosation reaction is possible, e. g., with ascorbic acid, which is oxidized by nitrite to its dehydro form, while nitrite is reduced to NO. Similarly, tocopherols and some other food constituents inhibit substitution reactions. Representative suitable measures to decrease exo-and endogenic nitrosamine hazards are ... 

V-Nitrosamines are potentially hazardous and should be handled in designated hoods and with protective clothing. Nitrosamines can be destroyed by treatment with aluminum—nickel alloy under basic conditions (78,79). 

From the above it can be concluded that the risk for lung cancer induction from chronic indoor exposure to Rn-d is unlikely to be higher than 1.10 4/mSv. in order to understand the magnitude of this risk it has to be emphasized that man can be exposed to a multitude of different hazardous materials in the indoor atmosphere besides Rn-d, such as formaldehyde, nitrogen dioxide, carbon monoxide, nitrosamines, polyaromatic hydrocarbons, volatile organic compounds, asbestos and pesticides (Gammage and Kaye, 1985). 

A survey is made of French and European Union legislation relating to hazardous chemicals in the workplace, and particular attention is paid to regulations concerning exposure to chemicals in the rubber industiy. The carcinogenicity of nitrosamines formed during vulcanisation processes is examined, and methods used in their detection are discussed. 2 refs. 

Ito et al. (1995) examined the combined dietary administration to rats of 19 organophosphate pesticides and 1 organochlorine pesticide, aU permitted for use in Japan, each at its ADI level. The dietary exposure at this level did not enhance the development of diethyl nitrosamine initiated pre-neoplastic lesions whereas at 100 times the ADI, the number and area of lesions were increased. The authors concluded that the study provided direct support for the present use of the safety factor approach in the quantitative hazard evaluation of pesticides. 

Relative Risks of Nitrosamines. The mere existence of reproducible variations in carcinogenicity from one nitrosamine to another is directly relevant to the question of potential human health hazards from environmental nitrosamines. The problem of nitrosamines in cooked bacon is a simple and straightforward example. 

This analysis, along with some observations concerning the possible absolute hazards arising from nitrosamines in bacon, has been detailed in an earlier report (17). 

In summary, it appears that the differences in carcinogenic potency for both cyclic and acyclic N-nitrosodialkylamines are real and systematic, and that the potencies of environmental nitrosamines should be considered in assessing the relative hazards associated with these compounds. In addition, it can be shown that the carcinogenicity of nitrosamines can be associated... 

With regard to worker exposure to nitrosamines present in agricultural chemicals, the volatile nature of these materials suggests inhalation and dermal contact as the major routes of absorption. There is a potential hazard of exposure to field applicators, especially commercial farmers and growers who regularly spray their crops and land. Manufacturers of the formulations may have workers who are exposed to unusually... 

A Health Hazard Evaluation of Nitrosamines in a Tire Manufacturing Plant... 

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). 

Specifications require a statement as to the content of the active ingredient. It is also important that the content of impurities be defined if these interfere with the active ingredient, or are phytotoxic, such as -nitrophenol in para-thion or are corrosive to packages or machinery or induce chemical degradation or are unduly hazardous to man or the environment, such as chlorinated dioxins or nitrosamines. 

DOT CLASSIFICATION Forbidden (dry) Explosive I.IA Label Explosive I.IA SAFETY PROFILE Many nitrosamines are carcinogens. A very dangerous fire hazard. 

The polychlorinated biphenyls occur widely as environmental pollutants and have been observed in the food chain. GC-MS has been applied in various aspects of their analysis (for leading references see [504, 505,513]). In the general area of food chemistry and contamination control, claims for the presence of carcinogenic nitrosamines in foodstuffs have been evaluated by specific GC-MS techniques [514,515]. However, it has been suggested that there may be a current over obsessive interest in the possible hazards of a few ppb of nitrosoamines in food [516]. 

RIFM has recommended discontinuance of the use of acetylethyl tetramethyltetralin, 6-methylcoumarin, musk ambrette, and musk ketone. Another self-imposed ingredient restriction concerns the use of potential nitrosating agents in products containing various (secondary) alkanol amines, in light of the hazard of nitrosamine formation. In the European Union, (E.U.), the use of tri- and di-ethanolamine is restricted. 

Nitrosamine exposure is not an acute hazard. Flealth hazards associated with nitrosamine exposure are limited to cancer, and liver and kidney damage associated with chronic exposure. No specific... 

Another potential hazard in using fillers is the possible formation of toxic materials. Twelve samples of siliea fillers were studied with respect to their effect on the formation of N-nitrosamines in rubber compounds. Figures 20.1 and 20.2 provide these data. Filler absorption of NO inereases as the fillerk specific surface area increases. This absorbed NO was found to react with amines in rubber and to produee N-nitrosamines. Greater absorption... 

Preoccupation with the occurrence and behavior of minute amounts of nitrosamines in the human environment will probably divert skills from more profitable studies of the behavior of nitrosamines in experimental systems... If [this essay] leaves the reader with the impression that nitrosamines have a much greater potential as research tools than they have as health hazards, it will have served its purpose. 

Despite intensive experimental investigations, however, the hazard to humans from small doses of nitrosamines present in our food and water are difficult to assess, and until further experimental evidence is available, no firm opinion can be given. 

Nitrosoamines or nitrasamines are derivatives of amines, containing V-nitroso groups ( N—N=0)- Typically, a nitrosamine is formed by the reaction of an amine with a nitrite. These substances are also produced by the action of nitrate-reducing bacteria. Nitrosoamines occur in trace quantities in tobacco smoke, processed food, meat products, and salted fish. Many nitrosoamines are used as gasoline and lubricant additives, antioxidants, stabilizers, and softeners for copolymers. These compounds are noncombustible liquids or solids at ambient temperature. The hazardous properties of nitrosoamines are different from those of their parent aliphatic or aromatic amines. 

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