When receiving biological fluids such as nutrients, blood or blood components that have been stored in PVC containers, patients may be exposed to plasticisers via the intravenous route. PVC tubing used either in the administration of fluids or for dialysis may also contribute to the exposure of plasticisers.
When lipid-containing fluids (i.e. fluids which contain fats) are stored in plasticised PVC containers or conveyed through PVC tubing, some of the plasticiser will migrate into the fluid. The rate of migration is highly dependent on the properties of the fluid, storage time, storage temperature and the type of plasticiser used. Due to the low solubility of plasticisers in water, aqueous medical solutions extract practically no plasticiser from containers or tubing. Data collected on DEHP (the most commonly used plasticiser in medical devices) exposure in patients undergoing medical treatment have shown that even the highest exposures of DEHP provide a significant safety margin when compared with levels of exposure which have been seen to produce no effect in animal studies.
However, responding to public concerns, despite the absence of any adverse effect observed in humans through exposure to DEHP via medical devices, the EU-Commission has asked a scientific committee to look into the issue. This committee, the Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR), published its Opinion during 2008. The Opinion stated that “there is limited evidence suggesting a relation between DEHP exposure and some effects in humans” and “so far, there is no conclusive scientific evidence that DEHP exposure via medical treatments has harmful effects in humans”.
The Opinion goes on to take a precautionary approach by stating that, even in the absence of clinical or epidemiological evidence of harmful effects in humans, “there is a reason for some concern for premature born male neonates for which the DEHP exposure may be transiently above the dose inducing reproductive toxicity in animal studies.” According to the Committee a few other patient groups besides neonates may also be at risk, i.e. “the male foetus and male infant of pregnant women or lactating women, respectively, in haemodialysis”.
The reason for concern of these patient groups is that the potential level of DEHP-exposure can exceed the exposure limits determined (with an appropriate safety margin) from doses that result in reproductive effects observed during animal studies.