Carcinogenic distillates

A second vital observation was made when Mayneord, a physicist, joined in the research effort and decided to examine the conspicuous fluorescence of the many carcinogenic distillates present in Kennaway s laboratory. He found that most of the carcinogenic tars exhibited a common fluorescence spectrum (X 400, 418 and 440 nm) but, in subsequent studies with Hieger, none of the hydrocarbons available at that time exhibited these spectral characteristics (7 ). The spectrum of benz[a]anthracene was found to be similar to, but of longer wavelength than, that of the carcinogenic preparations but this similarity directed Kennaway s attention to Clar s report of the synthesis of dibenz[a hjanthracene (10). Tumors were obtained when this hydrocarbon was repeatedly painted on to mice and thus it was established that the properties necessary to elicit tumors in animals were contained within the structure of a single pure chemical compound (11). 

Sodium hydroxide [CORROSIVE] Chloroform [TOXIC CARCINOGEN] Distilled water... 

Ethyl Carbamate. In November 1985, the Canadian Government indicated that it had detected ethyl carbamate [51-79-6] (urethane), a suspected carcinogen, in some wines and distilled spirits. Since that time, the U.S. distilled spirits industry has mounted a serious effort to monitor and reduce the amount of ethyl carbamate (EC) in its products. In December 1985, the Canadian Government set limits of 150 ppb in distilled spirits and 400 ppb in fmit brandies, cordials, and Hqueurs. The FDA accepted a plan in 1987 from the Distilled Spirits Council of the United States (DISCUS) to reduce ethyl carbamate in whiskey to 125 ppb or less, beginning with all new production in January 1989. 

Phosphorus (white) [7723-14-0] M 31.0, m 590, d 1.82. Purified by melting under dilute H2S04" dichromate (possible carcinogen) mixture and allowed to stand for several days in the dark at room temperature. It remains liquid, and the initial milky appearance due to insoluble, oxidisable material gradually disappears. The phosporus can then be distilled under vacuum in the dark [Holmes Trans Faraday Soc 58 1916... 

Man has served as the unintentional guinea pig for the identification of some major classes of carcinogens. These include the polycyclic aromatic hydrocarbons (PAH), or polyarenes, which have been identified as the active components of soot, which was recognized by the London surgeon Percivall Pott two centuries ago as responsible for cancer of the scrotum in chimney sweeps. Subsequently, polycyclic hydrocarbons have been implicated as agents responsible for skin cancer in other occupations such as shale oil distillation and mule spinning in the cotton industry. 

Nessel, C.S., A comprehensive evaluation of the carcinogenic potential of middle distillate fuels, Drug Chem. Toxicol., 22, 165, 1999. 

Benzene is reagent grade quality and distilled from sodium/benzophenone ketyl. This solvent is a suspect carcinogen and should be handled in a well-ventilated hood. 

Biles R, McKee R, Lewis S, et al. 1988. Dermal carcinogenic activity of petroleum-derived middle distillate fuels. Toxicology 53 301-314. 

Blackburn GR, Deitch RA, Schreiner CA, et al. 1986. Predicting carcinogenicity of petroleum distillation fractions using a modified Salmonella mutagenicity assay. Cell Biol Toxicol 2 63-84. 

Lewis SC, King RW, Cragg ST, et al. 1984. Skin carcinogenic potential of petroleum hydrocarbons n. Crade oil, distillate fractions and chemical class subfractions. In MacFarland HN, Holdsworth CE, MacGregot JA, et al., eds. Advances in modem environmental toxicology. Vol. VI Applied toxicology of petroleum hydrocarbons. Princeton, NJ Princeton Scientific Publishers, Inc. 

Other examples are carcinogenicity studies on complex mixtures (petroleum middle distillates, foundry fumes, pesticides, heterocyclic amines, diesel exhaust, and solid particles) neurotoxicity studies of mixtures of solvents alone or in combination with exposure to physical factors and toxicity stndies of outdoor air pollutants, focusing... 

Safrole, which is both toxic and carcinogenic, occurs in sassafras oil up to 90%. There are two commercially important sassafras oils the Brazilian oil is obtained from the trunk wood of Ocotea pretiosa and the Chinese oil is obtained from Cinnamomum camphora by steam distillation of wood chips. Safrole from... 

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). 

Dichloromethyl methyl ether (98%) was purchased from Aldrich Chemical Company, Inc. (listed as a, a-dichloromethyl methyl ether), and used without purification. Better results can be obtained if the material is distilled under nitrogen prior to use. Unlike chloromethyl methyl ether and bis(chloromethyl) ether, dichloromethyl methyl ether is reported to have no significant carcinogenic activity.6 However, as a precaution it should be handled carefully in a well-ventilated hood. 

The hexamethylphosphorus triamide is obtained from the Eastman Kodak Company. It is distilled under reduced pressure (water aspirator) to yield a clear, colorless oil, b.p. 46-48° (7 mm.). It is then stored under nitrogen (rubber septums should be avoided as they tend to deteriorate on prolonged contact with phosphine vapors). Hexamethylphosphorus triamide that has not been freshly distilled often requires much longer reaction times. Since this chemical is an irritant, all operations with it should be performed in a well-ventilated hood. Hexamethylphosphoramide is a classified carcinogen see Org. Syn., 55, 103 (1976). It should not be confused with hexamethylphosphorus triamide used in this preparation. 

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