Sunday, April 20, 2014
Susan Freinkel / The Washington Post
(Continued from page 1)
Plastic food packaging is a major source of potentially harmful chemicals, but finding out which ones might have seeped into your food is nearly impossible.
The Associated Press
The American Chemistry Council said there is no cause for concern. "All materials intended for contact with food must meet stringent FDA safety requirements before they are allowed on the market," said spokeswoman Kathryn Murray St. John. "Scientific experts review the full weight of all the evidence when making such safety determinations."
When it comes to food packaging and processing, among the most frequently studied agents are phthalates, a family of chemicals used in lubricants and solvents and to make polyvinyl chloride pliable. (PVC is used throughout the food processing and packaging industries for such things as tubing, conveyor belts, food-prep gloves and packaging.)
Because they are not chemically bonded to the plastic, phthalates can escape fairly easily. Some appear to do little harm, but animal studies and human epidemiological studies suggest that one phthalate, called DEHP, can interfere with testosterone during development. Studies have associated low-dose exposure to the chemical with male reproductive disorders, thyroid dysfunction and subtle behavioral changes.
But measuring the amount of phthalates that end up in food is notoriously difficult. Because these chemicals are ubiquitous, they contaminate equipment in even purportedly sterile labs.
Perhaps the most controversial chemical in food packaging is BPA, which is chiefly found in the epoxy lining of food cans and which mimics natural estrogen in the body. Many researchers have correlated low-dose exposures to BPA with later problems such as breast cancer, heart disease and diabetes. But other studies have found no association. Canada declared BPA toxic in October 2010, but industry and regulators in the United States and other countries maintain that health concerns are overblown.
Last month, the FDA denied a petition to ban the chemical.
The fact that a plastic bottle or bag or tub can leach chemicals doesn't necessarily make it a hazard to human health. Indeed, to the FDA, the key issue isn't whether a chemical can migrate into food, but how much of that substance consumers might ingest.
If simulations and modeling studies predict that a serving contains less than 0.5 parts per billion of a suspect chemical – equivalent to half a grain of salt in an Olympic-size swimming pool – FDA's guidance does not call for any further safety testing.
On the premise that the dose makes the poison, the agency has approved a number of potentially hazardous substances for food-contact uses, including phosphoric acid, vinyl chloride and formaldehyde.
But critics now question that logic. For one thing, it doesn't take into account the emerging science on chemicals that interfere with natural hormones and might be harmful at much lower doses than has been thought to cause health problems.
According to Jane Muncke, a Swiss researcher who has reviewed decades' worth of literature on chemicals used in packaging, at least 50 compounds with known or suspected endocrine-disrupting activity have been approved as food-contact materials.
"Some of those chemicals were approved back in the 1960s, and I think we've learned a few things about health since then," said Thomas Neltner, director of a Pew Charitable Trusts project that examines how the FDA regulates food additives.
Another criticism is that the FDA doesn't consider cumulative dietary exposure.
"The risk assessments have been done only one chemical at a time, and yet that's not how we eat," said Arnold Schecter, an environmental health specialist at the University of Texas Health Science Center.
Others are concerned that the FDA relies on manufacturers to provide migration data and preliminary safety information, and that the agency protects its findings as confidential.
So consumers have no way of knowing what chemicals, and in what amounts, they are putting on the table every day.