Diethylhexylphthalate as an environmental contaminant--a review.

Di(2-ethylhexyl)phthalate (DEHP) is a priority pollutant in several countries; annual production amounts to 3-4 million tonnes. Approximately 95% is used as a plasticizer in polyvinylchloride (PVC). DEHP is emitted to the environment during the production of plastics and plastic products, during their use and after disposal. In the environment, physico-chemical degradation of DEHP is practically non-existent. Biodegradation occurs readily under aerobic conditions (t1/2 = 2-4 weeks), but not under anaerobic conditions. The acute toxicity of DEHP to mammals is low. Many subchronic and chronic effects have, however, been identified. The most important of these are: influence on the liver and energy metabolism, teratogenicity, adverse effects on male reproductive organs, carcinogenicity and influence on the immune system. On the basis of figures concerning human exposure, most of these effects are not likely to occur. With respect to carcinogenicity the situation is uncertain, especially for some risk groups. The ecotoxicology of DEHP is especially relevant for aquatic communities where data are contradictory: several authors have found adverse effects on Daphnia and fish species after exposure to the present environmental concentrations; others, however, produced less alarming results. Emissions of DEHP can be reduced by the biological treatment of wastewater and waste gas, the use of alternative plasticizers in PVC or the substitution of other plastics for PVC.