The uphill battle to educate consumers on phthalates continues, with recent studies bringing attention — and misinformation — about plastics into the spotlight.
Two studies out of New York University have researchers linking exposure to phthalates used as replacements for DEHP to both high blood pressure and insulin resistance in children and teenagers.
In the first study, published in the journal Hypertension, authors Teresa Attina and Leonardo Trasande, conclude that every 10-fold increase in phthalate exposure results in a 1.1 mm of mercury increase in blood pressure. The other study, published in The Journal of Clinical Endocrinology and Metabolism, says one in three adolescents with the highest DINP levels had the highest insulin resistance, putting them at risk for developing Type 2 diabetes.
A third study out this month, by a team of researchers at the University of California-Riverside and published in the journal Environmental Science and Technology, warns phthalates are being absorbed from the soil by plants. In cultivation experiments with lettuce, strawberries and carrots, researchers found DBP and DEHP and their primary metabolites in the plants. However, they also concluded that there was little movement of the phthalates from roots to leaves and that the phthalates were readily converted in the plant tissue to their monoesters.
In spite of ultimate conclusions or small sample populations, these studies and others like them bring out the worst and sometimes even the strangest types of “plastics panic.” Trasande, the NYU professor who studied phthalates, blood pressure and insulin, apparently offered his own “safe and simple steps” to avoid phthalates, including keeping plastic containers out of the microwave and dishwasher, discarding scratched plastic containers as their “protective coating” could be breached and expose users to phthalates and generally avoiding containers with 3, 6 or 7 resin ID codes. The “tips” were quickly picked up across the internet and on television, making appearances on NBC's Today show and the CBS Morning News.
That the vinyl and polystyrene “visual aids” on TV weren't actually items made with phthalates or anything someone would put in the microwave in the first place was hardly surprising to the American Chemistry Council's Steve Russell.
“As the plastics industry already knows, there is quite a bit of confusion among consumers about the resin identification codes, codes that were established to assist with and improve recycling so that plastics could be sorted more easily. That resin ID code has been frequently and widely misreported as being as a means to a way to identify what materials are in the plastics,” said Russell, ACC's vice president of plastics. “That's why ACC and [the Society of the Plastics Industry Inc.] and [the Association of Postconsumer Plastic Recyclers] and other organizations are working to develop better guidance on recycling by the type of container rather than the resin ID code. And hopefully cut down on some of the misreporting.”
Phthalates frequently get presented to those outside the industry as something new, said Eileen Conneely, high phthalates panel manager at ACC, even though they have been in use, and safe, for 50 years.
“The average consumer doesn't know about phthalates,” she said.
All these journal articles pretty much have the same caveats from their authors, that further studies are needed, Conneely said, even though phthalates have been thoroughly tested and found safe for commercial and consumer use.
“Phthalates are used as a softener for PVC plastics. Generally you're not going to find them in any microwavable containers,” she said. Phthalates are more commonly found in building and construction materials - wire and cable, roofing membranes - than food-contact plastics.
ACC has website, www.phthalates.org, to help better educate everyone, inside and outside the plastics industry, on how the plasticizers work, why they are used and their 50-year safety record. Conneely and Russell both acknowledge getting the right information out about phthalates and plastics in general is an uphill battle.
“Unfortunately, misreporting of the facts about plastics and their safety is something that happens a lot,” Russell said.
Gayle S. Putrich is a Washington-based Plastics News reporter. Follow her on Twitter @gsputrich