Concerns about Phthalates

• Reasons for Concern
• What about Other Plasticisers?
• The Swan Studies

Reasons for Concern

Over the last 20 years, concern has grown about the safety of the phthalate DEHP, the phthalate most commonly used to soften PVC medical devices.

Because DEHP is not bound to the PVC matrix, it leaches out from medical devices into the solutions the devices are transporting into the patient. The effect is particularly pronounced in fatty solutions, such as feeding formulations.

The male reproductive tract appears to be the most susceptible organ. Because DEHP alters the way the reproductive tract develops, exposure leads to permanent deformities and effects on fertility.

• hypospadia, a deformity of the penis
• undescended testicles, which indicates
  increased risk of testicular cancer later in life
• reduced sperm count and fertility
• indications of feminisation (see Swan studies)

What about Other Plasticisers?

DEHP isn't the only plasticiser — other phthalates such as DINCH are being touted as alternatives, as well as non-phthalate plasticisers such as citrates and adipates. There are two fundamental problems with these: firstly, much like DEHP there is little data on their safety; secondly, using a different plasticiser doesn't address the problems with the production and disposal of PVC.

It is therefore best to use PVC-free plastics wherever possible.

The Swan Studies

Shanna Swan, a professor at the University of Rochester School of Medicine and Dentistry, is well-known for research connecting environmental exposure to DEHP with developmental problems in boys.

Swan has completed two studies. Her most recent, of 106 mothers and sons, is her second to suggest phthalates are affecting humans.

Swan measured phthalate levels in mothers' urine during pregnancy, then examined the babies at 12 months. Boys whose mothers had the highest phthalate levels were more likely to have smaller penises, a shorter distance between the anus and base of the penis, and undescended testicles.

The US National Toxicology Panel is dismissive of ano-genital measurements as a "novel index" whose relevance in humans "has not been established". However, HCWH believes Swan's research is significant as it indicates environmental exposure to DEHP is sufficient to interfere with the sexual development of young males, with potential repercussions for developing cancer and other problems later in life.

For independent information, see Wikipedia's articles on DEHP and phthalates.