Carcinogenic materials

Swallowing. If it is sufficiently irritant or caustic, a swallowed material may cause local effects on the mouth, pharynx, esophagus, and stomach. Additionally, carcinogenic materials may induce tumor formation in the alimentary tract. Also, the gastrointestinal tract is an important route by which toxic materials are absorbed. The sites of absorption and factors regulating absorption have been reviewed (42,43). 

Discussion. General procedures for the determination of nitrites are usually based upon some form of diazotisation reaction, often involving carcinogenic materials such as the naphthylamines. In the following method these compounds are avoided. 

Most of the materials used in the manufacture of chemicals are poisonous, to some extent. The potential hazard will depend on the inherent toxicity of the material and the frequency and duration of any exposure. It is usual to distinguish between the short-term effects (acute) and the long-term effects (chronic). A highly toxic material that causes immediate injury, such as phosgene or chlorine, would be classified as a safety hazard. Whereas a material whose effect was only apparent after long exposure at low concentrations, for instance, carcinogenic materials, such as vinyl chloride, would be classified as industrial... 

It is presumed that the effect of carcinogenic materials is to produce critical cell damage. Thus, carcinogenic health effects models generally are dose (i.e., integrated exposure) models, not exposure models. The lack of firm statistical bases often leads to the adoption of nonthreshold, linear models, even though thresholds and nonlinear effects might be expected. 

In the preparation of naphthalene intermediates the reactions must be employed in the correct sequence to achieve a desired orientation in the final product. A further crucial consideration can be the need to avoid steps that would result in the formation of carcinogenic materials. These points are illustrated in the following examples. 

Although various restrictions have been placed on carbon particulate emissions from different types of power plants, these particles can play a beneficial, as well as a detrimental, role in the overall plant process. The detrimental effects are well known. The presence of particulates in gas turbines can severely affect the lifetime of the blades soot particulates in diesel engines absorb carcinogenic materials, thereby posing a health hazard. It... 

Finally, some recognition must be made of the term carcinogen since many of the environmental effects noted in this book can lead to cancer. Carcinogens are cancer-causing substances, and there is a growing awareness of the presence of carcinogenic materials in the environment. A classification scheme is provided for such materials (Table 1.1). The number of substances with which a person... 

In a distillation apparatus fitted with mechanical stirrer, thermometer, and provisions for adding solids, to an agitated mixture of 26.7 gm (0.187 mole) erf 2-naphthylamine (CAUTION carcinogenic material) and 20 gm (0.163 mole) of nitrobenzene maintained at 180°C is added slowly 17 gm of powdered sodium hydroxide over a 20 min period. After completion of the addition, heating is continued for 10 min. After cooling, the reaction mixture is treated repeatedly with dilute hydrochloric acid. The excess nitrobenzene is then separated by steam distillation. The residue from the steam distillation is treated with ethanol at 70°C to precipitate insoluble impurities which are removed by filtration. On cooling the filtrate, product cyrstals separate which, after filtration, are taken up in petroleum ether, leaving petroleum ether-insoluble impurities behind. The petroleum ether extract is evaporated to dryness and the residue is recrystallized from ethanol at 75°C yield 17 gm (41 %), m.p. 84°C. 

Utilization of coal and oil shale to produce liquid and gaseous synfuels results in the generation of many hazardous sub-tances. Workers in these synfuel plants are likely to be exposed to potentially carcinogenic materials present in coal tars and oils. Among the various pathways of exposure, skin contamination by direct contact transfer or by adsorption of vapors and particulates into the skin presents a serious occupational health hazard. The skin irritant and potential carcinogenic properties of raw syncrudes and their distillate fractions have been reported (1. 2, 3). 

Most of the work on the inhibition of oxidative degradation of HTPB by incorporating anti-oxidants is in the form of patents or classified reports [225-227]. The use of N-phenyl-P-naphthylamine (PBNA) has been extensively studied [226, 228] for this purpose but it is reported to be a carcinogenic material and hence banned for use as a propellant ingredient in developed countries. 

The use of carcinogenic material should be avoided as far as possible, by replacement with non-toxic or at least less toxic substances. If their use cannot be avoided, appropriate technical and medicinal measures should be applied in order to protect the workers from their effects. Among such measures, the reduction of the exposure in terms of concentration and duration as well as a medical follow-up may be required. The exposure can be limited by using closed systems, avoiding any direct contact with the substance, or personal protection equipment. Moreover, the number of exposed operators should be limited. 

Cyclosporin Cyclosporin should not be administered through PVC tubing or stored in PVC containers, since it leaches some carcinogenic materials.211 Cyclosporin was less stable in dilute NaCl solutions and glucose and requires extensive mixing.212 The bioavailability of cyclosporin appears to increase if taken with food. Better bioavailability is reported with some microemulsions. 

Decontamination/Collection. Research operations should be analyzed to determine the types of waste, quantities of carcinogenic material, and handling procedures to be employed. All chemical carcinogens, including those contained in animal carcasses, should be deactivated, degraded if feasible, or packaged... 

Collection of chemical carcinogens, all waste products, animal carcasses and other materials from the laboratory should be performed by designated personnel on a scheduled basis or when necessary. The suspect or carcinogenic materials should not be placed on uncontrolled loading docks for pickup by general refuse collection personnel. At the National Institutes of Health, the special collection of hazardous materials, including chemical carcinogens, is done by personnel of the Fire Department. In the instance of one of the NCI contractor sites, Frederick Cancer Research Center, located at a military post, personnel from the safety offices perform this service. 

In January, 1976, the Environmental Protection Agency (17, 18) reported that radioactive material migrated from a surface burial facility and extended to the surrounding environment for several hundred feet from its original site. Radioactive material was detected in surface soil samples, in soil cores, in sediments from deep monitoring wells, and in sediments from intermittent streams which drained the burial sites. Again, whenever possible, if carcinogenic material cannot be rendered harmless, it should be disposed of by incineration. 

U.S. Department of Health, Education, and Welfare, National Institutes of Health. Disposal of suspected or known chemical carcinogenic material at NIH. Manual Issuance 3032-2. NIH - 1511-1. 

Questionable carcinogen. Mutation data reported. See also CARBON. A nuisance dust in high concentrations. While it is true that the tiny particulates of carbon black contain some molecules of carcinogenic materials, the carcinogens are apparently held tightly and are not eluted by hot or cold water, gastric juices, or blood plasma. 

Although various restrictions have been placed on carbon particulate emissions from different types of power plants, these particles can play a beneficial, as well as a detrimental, role in the overall plant process. The detrimental effects are well known. The presence of particulates in gas turbines can severely affect the lifetime of the blades soot particulates in diesel engines absorb carcinogenic materials, thereby posing a health hazard. It has even been postulated that, after a nuclear blast, the subsequent fires would create enormous amounts of soot whose dispersal into the atmosphere would absorb enough of the sun s radiation to create a nuclear winter on Earth. Nevertheless, particulates can be useful. In many industrial furnaces, for example, the presence of carbon particulates increases the radiative power of the flame, and thus can increase appreciably the heat transfer rates. 

A irbome particulate matter, which is formed by the condensation of gases or vapors or by mechanical or communitive processes, has been shown by many researchers to aflFect both flora and fauna. The two extremes of these affects are the accumulation of inert materials and of toxic or carcinogenic materials which lead to the eventual death of the biological specimen. As a result of such studies, society has attempted to reduce the total atmospheric burden by the enaction of emission control... 

As a starting point we proposed the use of carbon isotopes, and consequently produced and experimented with carbon 13. We also synthesized a carcinogenic material tagged with carbon 14 and conceived the possibility of finding it in the cancer tumors produced on animals. 

The new edition is aimed more to be a laboratory manual than a textbook. With this aim in mind, the text has been rearranged and shortened. Furthermore, dangerous experiments and those involving carcinogenic materials have been removed. 

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