Plasticizer Interaction with Stored Blood Produces a Toxic Metabolite, Mono(2-Ethylhexyl)Phthalate

Abstract

AbstractMost medical devices utilized in blood storage and transfusion, as well as in many medical and surgical procedures, are manufactured with polyvinylchloride (PVC) plastic containing the plasticizer di(2-ethylhexyl)phthalate (DEHP). During exposure of blood to the plastic surface, the DEHP is leached into the plasma where it is converted to mono(2-ethylhexyl)phthalate (MEHP) by a plasma enzyme in vivo or ex vivo during storage in plastic containers. The toxic effects of MEHP when infused into rats were investigated. The amount of MEHP infused was based on MEHP levels found in a variety of stored blood products (>6 ug/mL in red cell concentrates) and values actually measured during exchange transfusion (5 ug/mL) and cardiopulmonary bypass surgery (2.7 ug/mL). When the circulating level of MEHP in the rat's blood was >125 ug/mL, a greater than 50% decrease in heart rate and blood pressure was observed. This represents a margin of safety of only 25 fold higher than levels measured in humans during exchange transfusions. Although DEHP and MEHP have low oral toxicity, acute exposure by infusion may have lethal effects.