Vinyl chloride, carcinogenicity

P. R. Lawrence, T. R. Proctor, and P. Politzer, Int. ]. Quantum Chem., 26, 425 (1984). Reactive Properties of rrans-Dichloro-oxirane in Relation to Carcinogenicities of Vinyl Chloride and truns-Dichloro-ethylene. J. S. Murray and P. Politzer, Int. J. Quantum Chem., 31, 569 (1987). A Computational Study of Isomerization Equilibria Relation to Vinyl Chloride Carcinogenicity. P. Politzer and J. S. Murray, in Reviews in Computational Chemistry, Vol. 2, K. B. Lipkowitz and D. B. Boyd, Eds., VCH Publishers, New York, 1991, pp. 273—312. Molecular Electrostatic Potentials and Chemical Reactivity. 

C. Maltoni, Vinyl Chloride Carcinogenicity Available Scientific Evidence and Control Measures, Association of Plastics Manufacturers in Europe, Brussels, 1986. 

Vinyhdene chloride is hepatotoxic, but does not appear to be a carcinogen (13—18). Pharmacokinetic studies indicate that the behavior of vinyl chloride and vinyhdene chloride in rats and mice is substantially different (19). No unusual health problems have been observed in workers exposed to vinyhdene chloride monomer over varying periods (20). Because vinyhdene chloride degrades rapidly in the atmosphere, air pollution is not likely to be a problem (21). Worker exposure is the main concern. Sampling techniques for monitoring worker exposure to vinyhdene chloride vapor are being developed (22). 

Poly(vinyl chloride). Poly(vinyl chloride) (PVC) [9002-86-2] is a thermoplastic for building products. It is prepared by either the bulk or the suspension polymerization process. In each process residual monomer is removed because it is carcinogenic. Oxygen must be avoided throughout the process (see Vinyl polymers). 

Carcinogens Cancer-producing agents Skin Respiratory Bladder/urinary tract Liver Nasal Bone marrow Coal tar pitch dust crude anthracene dust mineral oil mist arsenic. Asbestos polycyclic aromatic hydrocarbons nickel ore arsenic bis-(chloromethyl) ether mustard gas. p-naphthylamine benzidine 4-am i nodi pheny lam ine. Vinyl chloride monomer. Mustard gas nickel ore. Benzene. 

Vinyl chloride -78 (Chloroethene) CH2 CHCI 472 4.0-22.0 1.0 2.1 -14 Colourless, sweet smelling liquefiable gas Polymerizes with light, heat, air or catalysts Normally inhibited Human carcinogen... 

Compounds considered carcinogenic that may be present in air emissions include benzene, butadiene, 1,2-dichloroethane, and vinyl chloride. A typical naphtha cracker at a petrochemical complex may release annually about 2,500 metric tons of alkenes, such as propylenes and ethylene, in producing 500,000 metric tons of ethylene. Boilers, process heaters, flares, and other process equipment (which in some cases may include catalyst regenerators) are responsible for the emission of PM (particulate matter), carbon monoxide, nitrogen oxides (200 tpy), based on 500,000 tpy of ethylene capacity, and sulfur oxides (600 tpy). 

Liver cancer can also be a consequence of exposure to hepatotoxic chemicals. Natural hepatocarcinogens include fungal aflatoxins. Synthetic hepato-carcinogens include nitrosoamines, certain chlorinated hydrocarbons, polychlorinated biphenyls (PCBs), chloroform, carbon tetrachloride, dimethyl-benzanthracene, and vinyl chloride.Table 5.15 lists the chemical compounds that induce liver cancer or cirrhosis in experimental animals or... 

The number of clear human epidemiologic studies is small. A total of approximately 50 compounds (c.g., benzene, vinyl chloride) and complex e.xposures (e.g., aluminum production, tobacco smoke) have sufficient data available to permit their classification as human carcinogens. The most potent human carcinogens known, the aflatoxins. are of natural origin. Their presence in food products through infestation by toxin-producing fungi constitute a serious problem in several tropical and subtropical countries. 

Degradation of trichloroethylene by anaerobes via reductive dehalogenation can be problematic because a common product is vinyl chloride, a known carcinogen (Ensley 1991). In an anaerobic colunm operated under methanogenic conditions, 100% transformation of injected tetrachloroethylene and trichloroethylene to... 

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... 

Tetrachoroethylene (perchloroethylene, PCE) is the only chlorinated ethene that resists aerobic biodegradation. This compound can be dechlorinated to less- or nonchlorinated ethenes only under anaerobic conditions. This process, known as reductive dehalogenation, was initially thought to be a co-metabolic activity. Recently, however, it was shown that some bacteria species can use PCE as terminal electron acceptor in their basic metabolism i.e., they couple their growth with the reductive dechlorination of PCE.35 Reductive dehalogenation is a promising method for the remediation of PCE-contaminated sites, provided that the process is well controlled to prevent the buildup of even more toxic intermediates, such as the vinyl chloride, a proven carcinogen. 

Lu, P.Y., Metcalf, R.L., Plummmer, N., Mandel, D. (1977) The environmental fate of three carcinogens benzol a Ipyrene, benzidine, and vinyl chloride evaluated in laboratory model ecosystems. Arch. Environ. Contam. Toxicol. 6, 129-142. 

Nature of the critical cellular adduct. It is to be expected that the properties and behavior of the adduct formed with DNA will be of key importance. For example, the carcinogenicity of vinyl chloride has been attributed to its 7-N-(2-oxoethyl) derivative of guanine [60, 61]. 

Significant activation occurs during the microbial metabolism of trichloroethylene (TCE). This compound was once widely used and now represents a major contaminant of many aquifers. Because TCE is metabolized by many bacteria, its elimination by bioremediation is being actively pursued. However, a major product frequently encountered is vinyl chloride, a potent carcinogen ... 

Vinyl chloride monomer (VCM) is the main substrate for the manufacture of polymers used as packaging materials for food. Since VCM is considered by lARC to be a human carcinogen, monomer levels in PVC food packaging materials are strictly controlled. To ensure a safe product, the residual content of VCM in the finished material or article is limited to one mg per kg in the final product (Council Directive 78/142/EEC). Furthermore, VCM should not be detectable in foodstuflfs. Commission Directives 80/766/EEC and 81/432/ EEC give the method of analysis for official control of the VCM level in food packaging materials and in foods - gas-phase chromatography using the headspace method, after dissolution or suspension of samples in N,N-dimethylacetamide. Both residual monomer content of the polymer and... 

Human exposure to migrating substances (e.g., di(2-ethylhexyl)phthalate) may result in reproductive disorders. There is a hazard that vinyl chloride monomers or bisphenol A migrating into food may induce carcinogenic, mutagenic, and teratogenic episodes. 

The 2003 ACGIH threshold limit valuetime-weighted average (TLV-TWA) for vinyl chloride is Ippm (3mg/m ) with an Al-confirmed human carcinogen designation. 

Maltoni C, Lefemine G Carcinogenicity bioassays of vinyl chloride. I. Research plan and early results. Environ Res 7 387-405, 1974... 

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