[ 02 July 2010 ]

The use of DEHP in Medical Devices

Medical devices are crucial to the high standards of modern healthcare that we now take for granted. The many thousands of different types of devices which exist today are advanced modern products that have to respond to highly specific performance requirements. For many of them, PVC softened with the plasticiser di(2-ethylhexyl) phthalate (DEHP) is the ideal material. DEHP - the member of the phthalate family used in almost all PVC healthcare applications - is actually specified by the European Pharmacopoeia as the plasticiser for blood bags. For the vast majority of its uses there is no concern about the safety of DEHP. Indeed, in September 2002 the European Union's Scientific Committee on Medicinal Products and Medical Devices published an Opinion in which they said they could make no recommendation to limit the use of DEHP, even for the most highly exposed patients. As a result of new information on exposure to DEHP, the EU Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) was subsequently asked to give another opinion on the safety of medical devices containing DEHP plasticised PVC or other plasticisers on neonates and other groups possibly at risk. In its opinion given in February 2008, SCENIHR says there is reason for some concern for prematurely born male neonates although follow-up studies after high DEHP exposures in neonates do not indicate there is an effect of DEHP on the development of the human male reproductive system. They say that some other patient groups with relatively high DEHP exposures, including male foetuses of pregnant women may also result in some risk. But they point out that as it may be difficult to obtain the same functionalities in certain medical devices as with those made of PVC plasticised with DEHP, the risk and benefits of using alternatives should be carefully evaluated on a case by case basis. "These high exposure levels during certain medical procedures have to be seen in the light of treatment needed and the availability of suitable alternatives for each medical treatment", says the Committees report. It also adds: "It should be noted that medical devices made from plasticised PVC provide many effective treatments and that DEHP is a particularly effective plasticiser. In addition to its beneficial effect on mechanical properties, DEHP also stabilises the membranes of red blood cells enabling blood product storage in PVC blood bags for several weeks." The three European Union Directives relating to medical devices stipulate rigorous and exhaustive testing of materials and govern the materials that can be employed. The campaign that has been launched by the Committee for Sustainable Development in Health is very misleading and it threatens to endanger patients by forcing doctors to use devices which may be of inferior quality. There is no evidence of humans having been harmed as a result of exposure to DEHP from medical devices. In fact the opposite is true - there are two studies on adults who were exposed to high levels of DEHP when they were in intensive care as premature infants and they both show no adverse effects.