Medtech Plasticizer Tied to ADHD in Children

Scientists have linked the plastic softeners in medical tubing to neurological problems in children hospitalized with critical illnesses.

Nancy Crotti

The softeners, known as phthalates, had previously been linked to ADHD, allergies, asthma, hormonal imbalances, insulin resistance, and obesity. FDA recommended reducing their use in medical devices as early as 2002, according to a report in the Washington Post.

"Phthalates have been banned from children's toys because of their potential toxic and hormone-disrupting effects, but they are still used to soften medical devices," said lead researcher Sören Verstraete, MD, of Katholieke Universiteit Leuven in Leuven, Belgium, in a statement. "We found a clear match between previously hospitalized children's long-term neurocognitive test results and their individual exposure to the phthalate DEHP during intensive care."

Di(2-ethylhexyl)phthalate, or DEHP, is the most commonly used plastic softener in medical devices made of polyvinyl chloride. Verstraete called the use of medical devices containing this phthalate "potentially harmful" for the brain development and function of critically ill children.

An alternative to DEHP known as DINCH that is also used in medical devices was found to also have troubling metabolic processes in mammals in a study published last year.

"Development of alternative plastic softeners for use in indwelling medical devices may be urgently indicated," he said.

The researchers studied 449 children who had been treated in a pediatric intensive care unit, and 100 healthy children. They tested for the presence of DEHP byproducts in the blood of 228 patients while they were in the PICU. The patients had one to 12 medical tubes and ranged in age from newborn to 16 years.

Four years later, the researchers performed neurological tests on all of the children. They found astrong association between a high exposure to DEHP during the PICU stay and attention deficit disorder. The researchers also conducted statistical analyses that adjusted for risk factors that could influence the neurocognitive outcome, as well as length of stay, complications, and treatments in the PICU.

They validated their finding in a different group of 221 PICU patients, according to the statement from the Endocrine Society.

Verstraete called the use of medical devices containing this phthalate "potentially harmful" to the brain development and function of critically ill children. "Development of alternative plastic softeners for use in indwelling medical devices may be urgently indicated," he added.

Congress banned phthalates from children's products in 2008.The Consumer Product Safety Commission permanently banned three phthalates, including DEHP and DPB, in products marketed to children younger than 12.

In December 2012, FDA restricted the use of both DBP and DEHP in pharmaceuticals, citing concerns that these chemicals are associated with health risks. 

Medtech companies, including Teknor Apex Co., have been studying and developing alternatives to DEHP for softening PVC.

DEHP has been used in an array of medical devices including IV bags and tubing, peritoneal dialysis bags and tubing, blood bags and tubing, heart bypass machine tubing, nasogastric feeding tubes, respiratory tubing, enteral nutrition, and feeding bags.

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