Jury still out on DEHP and medical devices

Words by Ole Grøndahl Hansen, project manager at PVCMed, an alliance of the PVC medical industry value chain

DEHP is one of the several plasticisers used in PVC medical devices. Scientists agree that DEHP can leach into the body from tubes, blood bags and other essential medical devices. A number of animal studies posit that DEHP can potentially harm reproduction among other adverse effects. Paradoxically, the main concern is whether patients are at risk from using life-saving medical devices.

The European Commission’s Scientific Committees have published opinions on DEHP in 2002, 2008 and 2014 (under review). These European Committees must give “sound and timely scientific advice” to the Commission based on “the principles of excellence, independence, impartiality [and] transparency. As such, their work forms the knowledge base of the legislative process regarding public health, consumer safety and the environment in the European Union.

The Committee on Emerging and Newly-Identified Health Risks (SCENIHR)—under whose wings the review of DEHP currently belongs—is composed of fifteen independent scientists from public research institutions appointed by the Commission for a three-year period.

The 2002 and 2008 opinions

According to the 2002 opinion, “there are no reports concerning any adverse effects in humans following exposure to DEHP-PVC, even in neonates or other groups of relatively high exposure.” Further, the Committee stressed that DEHP-PVC medical devices had contributed tremendously to health care. However, the lack of data did not rule out adverse effects on humans, and the authors called for further research.

In 2008, the SCENIHR assessed alternative plasticisers and new data on toxicity in animal and human studies. The verdict: “So far, there is no conclusive evidence that DEHP exposure via medical treatments has harmful effects in humans.” However, “the new information indicates that there is still a reason for some concern for prematurely born male neonates, because of the high human exposure during certain medical procedures. Again, further studies were recommended.

The authors advised a case-by-case approach for alternative plasticizers. Some could be suitable to replace DEHP, while others do not have the same functionalities. A risk assessment of the alternatives could not be performed due to lack of data.

The controversy and the 2014 update

In 2012, an LCA by consultant agency eco2win asserted that DEHP-PVC blood bags “pose a significant risk to human health, due to both PVC and DEHP. The PVC industry was surprised by these conclusions. The European Council of Vinyl Manufacturers commissioned the University of Manchester to review the eco2win LCA, which was found to be inadequate because it failed to follow key criteria normally expected from LCA studies. It also appeared to be motivated by a desire to phase out PVC blood bags regardless of the actual results.

Unfortunately, the 2014 update of the 2008 opinion didn’t provide a clearer picture. Male neonates, especially those in ICUs, are considered at high risk of DEHP exposure during medical procedures “due to their physical conditions, the immaturity of many systems and organs as well as their small size.” However, the 2014 Opinion states that “DEHP-containing plasticised PVC devices are important for many treatments and justified because of the benefits of these procedures.”

The 2014 draft opinion largely follows the previous opinion on alternative plasticizers. Some plasticizers’ toxicity and carcinogenicity were evaluated but human exposure data or information on leaching is “sparse” according to the draft opinion. For others, data on the toxicological profile is insufficient. The approval of the final SCENIHR opinion is expected by the end of April 2015.

An inconclusive conclusion and the road ahead

Authors of the 2014 update reject the asserted links between DEHP and diabetes, obesity and other illnesses in their review of epidemiological and clinical studies. Moreover, the SCENIHR emphasizes the importance of taking a cautious approach to life-saving medical devices.

The industry is actively working with relevant governmental bodies to find safe and suitable alternatives to DEHP in medical devices. Alternatives have been developed and are increasingly being used in a wide variety of medical applications allowing medical equipment purchasers to continue to benefit from PVC’s unique properties for patient comfort, economic affordability and hospital hygiene. A 2014 report by the Danish health and environment authorities and the PVCMed Alliance identified ten, already-in-use alternatives to DEHP and other phthalates in medical devices. Though more research is needed, most showed a better toxicological profile than DEHP.