Toluene teratogenicity

The most frequently used solvent is toluene. Toluene boils at 231°F but forms an azeotrope with water boiling at 183°F. Because this is below the system operating temperature, hazards are present because of flammability and volatility. In addition, toluene presents special problems from a personnel exposure viewpoint as a suspected teratogen. 

Chronic maternal inhalation abuse of toluene during pregnancy has been associated with teratogenic effects in a number of case reports. Manifestations include microcephaly. 

Ono, A., Sekita, K., Ohno, K., Hirose, A., Ogawa, Y, Saito, M., Naito, K., Kancko, T., Furuya, T., Matsumoto, K., Tanaka, S. Kurokawa, Y. (1995) Reproductive and develomental toxicity studies of toluene I. Teratogenicity study of inhalation exposure in pregnant rats. J. toxicol. Sci., 20, 109-134... 

Toluene 15 ml highly flammable, toxic by inhalation, ingestion or by absorption through skin, serious irritant, experimental teratogen... 

Benzene is suspected to cause leukemia as well as birth defects. Although many laboratories have tried to phase out the use of benzene in recent years, six of the laboratory manuals in Table 1 still use it. Toluene, which is a common substitute for benzene, is also on the list of potential teratogens. However, 1t appears to be much less toxic than benzene. When benzene or toluene is needed only as a solvent, some other hydrocarbon (such as hexane)... 

Of the twenty potentially teratogenic chemicals listed in Table 1, the ones that appear to present most risk for the pregnant chemistry student are the organic liquids given in Table 2. Some of these (aniline, butanone, carbon disulfide, formaldehyde, and phenol) could easily be omitted from introductory laboratory courses. Benzene and toluene might be substituted by xylene (or perhaps by other hydrocarbons), and both chloroform and carbon tetrachloride could be replaced by methylene chloride. 

SAFETY PROFILE Moderately toxic by ingestion, skin contact, intravenous, and intraperitoneal routes. Mildly toxic by inhalation and subcutaneous routes. An experimental teratogen. Other experimental reproductive effects. A mild eye and skin irritant. Combustible when exposed to heat or flame can react with oxidizing materials. Moderate explosion hazard in the form of vapor when exposed to heat or flame. Mixture with hydrogen peroxide + polyacrylamide gel + toluene is explosive when dry. To fight fire, use alcohol foam, dry chemical. See also GLYCOL ETHERS. 

Women of child-bearing age should be careful when handling any substance of unknown properties. Certain substances are highly suspect teratogens and will cause abnormalities in an embryo or fetus. Among these are benzene, toluene, xylene, aniline, nitrobenzene, phenol, formaldehyde, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), polychlori-... 

Some single organic solvents, for example, toluene, xylene, and ethanol, are known teratogens. Regretfully, many of the studies in the literature lump all organic solvent exposures together and fail to identify the specific... 

Because benzene is nonpolar, it cannot be passed in urine, and will remain in the body until oxidized. Benzene itself is not dangerous to health, but in order to be passed, it is oxidized by cytochrome P-450 in the liver. This produces benzene oxide, a highly teratogenic and carcinogenic compound. Benzene has been replaced by toluene as an industrial solvent, because toluene can be oxidized to benzoic acid, which is mostly harmless to health, and is quickly passed. The decomposition of benzoic acid into benzene and carbon dioxide in soda pop has become an issue recently. 

In conclusion, similar to benzene, toluene does not appear to be teratogenic. It is fetotoxic, causing a reduction in fetal weight in mice and rats and retarded ossification and some increase in skeletal anomalies in rats at doses that are below those toxic to the dam as well as at toxic doses. Embryolethality has also been seen with inhalation of very high concentrations lethal to some of the dams or following oral administration of non-toxic doses. ... 

Many monocyclic aromatic compounds, including chlorobenzene, dichlorobenzene, trichlorobenzene, tetrachlorobenzene, pentachlorobenzene, ethyl benzene, toluene, and nitrobenzene are not carcinogenic. By contrast, oral administration of hexachlorobenzene to hamsters produced liver tumors, liver haemangiotheliomas, and thyroid adenomas (LARC, 1979). Although hexachlorobenzene is also fetotoxic and produces some teratogenic effects,it is not mutagenic to yeast. Other compounds that are either promoters or known/suspected carcinogens include benzene, 2,6-dinitrotoluene, 2,4,6-... 

Table 19.2 summarizes the data reported by Holmberg in 1979, who first identified this phenomenon. values were not included in the Holmberg paper, but are added here to show lipophilicity and hydrophilicity. Holmberg identified 13 mothers who had been exposed to solvent mixtures on the job during pregnancies and the resultant CNS defects in their children. It should be noted that his report included one mother who was exposed only to toluene, a chemical that has since been established as teratogenic [4, 5]. 

Toluene 700 Psychiatric change, cognitive dysfunction, fatigue, myopathy, nephrotoxicity, teratogen Gasoline, paints, adhesives, inks, solvents 0.13 pgA by GC with FID 6 pg/ 1 by GC-MS... 

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