Human carcinogenic mixtures

It is very difficult to treat MDA as a single entity because the manufacturing processes of PMDA and MDA are essentially identical, with the exception of a separation step. This article focuses on the technology of 4,4 -MDA, and it also includes properties of isomers and oligomeric mixtures when they are of commercial importance. The 4,4 -MDA is a suspected human carcinogen, and therefore special handling of this material is required. AH of the MDA and PMDA produced is consumed in industries that are "destmctive" of MDA s chemical identity. Thus MDA loses its unique chemical identity and is not encountered by household consumers. 

Polycyclic aromatic hydrocarbons have been classified as human carcinogens because they induce cancers in experimental animals and because smoking and exposure to mixtures of chemicals containing polycyclic aromatic hydrocarbons in the workplace increase the risk of lung cancer in exposed individuals. In experimental animals, benzo(a)pyrene induces cancer in different organs depending on the route of administration.Furthermore, exposure to polycyclic aromatic hydrocarbons commonly occurs in occupations related to traffic (use of diesel engines in transportation and railways). 

According to OECD (2001b), the term carcinogen denotes a chemical substance or a mixture of chemical substances, which induce cancer or increase its incidence. Substances which have induced benign and malignant tumors in well-performed experimental studies on animals are considered also to be presumed or suspected human carcinogens unless there is strong evidence that the mechanism of tumor formation is not relevant for humans. ... 

Table 12.3 List of Agents, Substances, Mixtures, and Exposure Circumstances Known to be Human Carcinogens...

Sulfur mustards (designated H [mustard], HD [distilled mustard], and HT [HD and T mixture]) do not present acute lethal hazards. Their principal effect is severe blistering of the skin and mucous membranes. Epidemiological evidence indicates a causal relationship between exposure to mustard agent at high concentrations and the development of chronic nonreversible respiratory disorders, such as chronic bronchitis and asthma, and ocular diseases, such as delayed recurrent keratitis and prolonged, intractable conjunctivitis (IOM, 1993). Sulfur mustard has been classified as a known human carcinogen based on evidence of in-... 

Many of the hazards from the polymer industry arise from the monomers used as raw materials. Many monomers are reactive and flammable, with a tendency to form explosive vapor mixtures with air. All have a certain degree of toxicity vinyl chloride is a known human carcinogen. The combustion of many polymers may result in the evolution of toxic gases, such as hydrogen cyanide... 

TCDD is a possible human carcinogen when considered alone and a probable human carcinogen when considered in association with phenoxy herbicides and/or chlorophenols. The EPA has determined also that a mixture of CDDs with six chlorine atoms (4 of the 6 chlorine atoms at the 2, 3, 7, and 8 positions) is a probable human carcinogen. 

SAFETY PROFILE Suspected human carcinogen with experimental carcinogenic, neoplastigenic, and tumorigenic data. Experimental reproductive effects. Mutation data reported. A powerful oxidizer. Mixture with boron burns violently if ignited. See also CHROMIUM COMPOUNDS and CALCIUM COMPOUNDS. 

NIOSH REL TWA 15 ng(Ni)/m3 DOT CLASSIFICATION 5.1 Label Oxidizer SAFETY PROFILE Confirmed human carcinogen. Poison by intraperitoneal route. A powerful oxidizer. Mixtures with 2,2-dimethoxypropane explode when heated... 

Known or presumed human carcinogen including mixtures containing > 0.1% of such a substance. Signal word Danger... 

Suspected human carcinogen including mixtures Signal word Warning... 

Group 1 Known to be human carcinogens - this group is reserved for those chemicals where there is sufficient evidence of carcinogenicity from studies in humans which indicate a causal relationship between exposure to the agent, substance, or mixture and human cancer. 

Hazard Supports combustion, can form explosive mixture with air. Narcotic in high concentration. TLV 50 ppm not classifiable as a human carcinogen. 

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