Intake of plasticisers possibly higher than assumed

18-Aug-2003

Plasticisers keep plastic products pliant. They are used in so many areas of daily life that they can be described as ubiquitous. The consumer, therefore, frequently comes into contact with these substances. One of the most frequently used plasticisers is diethyl hexyl phthalate, in short DEHP. This substance is considered to be "well investigated" in terms of its health risk. A comprehensive risk assessment is currently being undertaken within the framework of the European existing chemicals programme. Despite the damaging effects which DEHP can trigger, more extensive, risk-reducing measures are only deemed to be necessary for children but not for adults. This is justified by the fact that the estimated average daily intake of DEHP is within the tolerable dose range. BfR has now challenged this assessment and bases its arguments on the new study findings from the University of Erlangen. According to these findings, the daily DEHP intake may be far higher than assumed up to now. An important and, up to now underestimated, source could be food. BfR has drawn the attention of the European Chemicals Bureau (ECB) to the new study results and requested a review of the assessment particularly with regard to the reprotoxic effect of DEHP. According to the Institute this could lead to a new assessment of the risk with corresponding repercussions for the need for exposurereducing measures.

DEHP belongs to the group of phthalates. It has a low acute toxicity; the substance is not classified as mutagenic. Depending on the dose, DEHP may have damaging effects on the testicles, kidneys and liver. In animal experiments the substance impairs reproductive capacity and leads to congenital abnormalities of the sexual organs in male offspring. DEHP is used in the production of a large range of plastic products, mainly PVC materials. The substance is present, for instance, in car parts (panelling, controls), clothing, toys, food packaging, cosmetics and medical devices (dialysis tubes). Because of its physical properties DEHP can dissolve or outgas when it comes into contact with liquids or fats from plastics and then directly reach the consumer or indoor air. The European existing substance report states that the average daily intake of DEHP through respiratory air, skin and blood is 12 microgram per kilogram body weight and day (µg/kg body weight/day). This value is far lower than the tolerable daily intake of 50 µg/kg body weight/day, laid down by the EU Scientific Committee for Food, at which no damage to health is to be expected. However, the food path was not taken into account when assessing the exposure of the consumers in the existing substance report.

Study findings of the University of Erlangen now seem to indicate that this could have led to a significant underestimation of the actual intake level. There they examined urine samples from 85 participants for levels of DEHP degradation products and calculated an intake level which was far higher than that given in the existing substance report for some of the test persons. For 5% of the participants it was higher than 52.1 µg/body weight/day. The authors suspected food exposed to DEHP as the source. As between 50 and 70% of DEHP is resorbed in the gastro-intestinal tract, this exposure route could contribute to a major degree to DEHP intake. The Institute, therefore, believes it is necessary to identify and reduce the main sources of exposure.

The Federal Institute for Risk Assessment has drawn the attention of the European Chemical Bureau to the results of the study and requested a review of the ongoing risk assessment. As DEHP is not only the plasticiser with the largest production volume but possibly also with the severest reprotoxic effect, this could lead to a new assessment of the risk and, by extension, to a need for minimisation measures. The only national application restrictions for DEHP in the food sector are those within the framework of the plastics recommendations of BfR. Furthermore, the Institute has recommended that no phthalates be used in toy manufacture.

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