Hazard teratogenic

Toxic air pollutants are pollutants which are hazardous to human health or the environment but which are not specifically regulated by the CAA. These pollutants are typically carcinogens, mutagens, and teratogens. The CAAA of 1977 failed to result in substantial reductions in the emissions of these harmful substances. 

U.S. EPA may list a waste as hazardous for any and all of the above reasons. The majority of listed wastes fall into the toxic waste category. To decide if a waste should be a toxic listed waste, U.S. EPA first determines whether it typically contains harmful chemical constituents. An appendix to RCRA contains a list of chemical compounds or elements that scientific studies have shown to have toxic, carcinogenic, mutagenic, or teratogenic effects on humans or other life forms. If a waste contains chemical constituents found on the appendix list, U.S. EPA then evaluates 11 other factors to determine if the wastestream is likely to pose a threat in the absence of special restrictions on its handling. These additional considerations include a risk assessment and study of past cases of damage caused by the waste. 

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. 

Christian, M.S. (1983). Assessment of reproductive toxicity State of the art. In Assessment of Reproductive and Teratogenic Hazards (Christian, M.S., Galbraith, M., Voytek, P. and Mehlman, M.A., Eds.). Princeton Scientific Publishers, Princeton, pp. 65-76. 

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. 

In order to fully assess the hazardous properties of a substance with respect to reproductive toxicity, the key data requirements are a two-generation study and a prenatal developmental toxicity (teratogenicity) smdy in two species (EC 2003). 

Re TA, Loehr RF, Rodwell DE, et al The absence of teratogenic hazard potential of g-phenylenediamine in Sprague-Dawley rats. FundamAppl Toxicol 1 421M25, 1981... 

Hexachlorobutadiene did not adversely affect reproduction in animals except at high doses (150 mg/kg/day for 10 weeks). Although there was some evidence of fetotoxicity in animals after inhalation (10 ppm) or oral (15 mg/kg/day) exposure, embryolethality and teratogenicity were not detected. Oral studies in animals indicate that hexachlorobutadiene may increase the risk of renal cancer at dose levels of 20 mg/kg/day. The effects of hexachlorobutadiene are most pronounced after repeated chronic exposure to low doses, suggesting that effects are cumulative. For this reason, there is greater concern for populations living near hazardous waste sites, where exposure to low levels may occur for long periods of time, than for acute exposure scenarios. 

Withdrawal of medication from an epileptic pregnant woman is not without its hazards, to the patient and possibly to the fetus. It is not clear whether maternal seizures can directly affect the fetus. If it is feasible, the physician should prescribe only one drug at the lowest effective dosage to minimize teratogenic risks. 

Key words Teratogenicity, Alternative methods, 3 Rs, Hazard assessment... 

Johnson EM (1980) A subvertebrate system for rapid determination of potential teratogenic hazards. J Environ Pathol Toxicol 4(5-6) 153-156... 

The mammalian result was considered indicative of a teratogenic potential when either the rodent or rabbit studies were positive. Therefore, a negative FETAX result was considered non-predictive if either the rat or rabbit were positive. To some extent, this biased the determined predictivity with respect to human hazard against FETAX, as for aspirin (see above). 

Hazard and Risk Assessment of Teratogenic Chemicais Under REACH... 

In accordance with both the old and the new European classification system teratogenic effects constitute a health hazard but a separate classification for teratogenicity is not provided. Instead, teratogens are classified as developmental toxicants, with developmental toxicity falling within the hazard class of reproductive toxicity. 

Assignment of Risk-Phrases/Hazard Statements to Teratogenic Chemicals... 

In the chemical safety report, the hazard assessment of a particular substance is based on the data set provided in the technical dossier. This contains substance-specific information on physicochemical properties as well as on toxicological and ecotoxicological hazards. One objective of the hazard assessment is the substance s hazard identification, which comprises the determination of its physicochemical and hazardous properties for the purpose of classification. Concerning human health hazards, both human and nonhuman information is taken into consideration and evaluated with respect to the classification criteria laid down in the Dangerous Substances Directive and in the CLP Regulation, respectively. However, in most cases human data do not exist, so the hazard identification has to be based on data from animal experiments. With respect to teratogenicity, this hazardous property may in principle be detected in the following toxicity studies ... 

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