If the food’s in plastic, what’s in the food?

By Susan Freinkel, Washington Post

In a study published last year in the journal Environmental Health Perspectives, researchers put five San Francisco families on a three-day diet of food that hadn’t been in contact with plastic.
When they compared urine samples before and after the diet, the scientists were stunned to see what a difference a few days could make: The participants’ levels of bisphenol A (BPA), which is used to harden polycarbonate plastic, plunged—by two-thirds, on average—while those of the phthalate DEHP, which imparts flexibility to plastics, dropped by more than half.

The findings seemed to confirm what many experts suspected: Plastic food packaging is a major source of these potentially harmful chemicals, which most Americans harbor in their bodies. Other studies have shown phthalates (pronounced THAL-ates) passing into food from processing equipment and food-prep gloves, gaskets and seals on non-plastic containers, inks used on labels—which can permeate packaging—and even the plastic film used in agriculture.

The government has long known that tiny amounts of chemicals used to make plastics can sometimes migrate into food. The Food and Drug Administration regulates these migrants as “indirect food additives” and has approved more than 3,000 such chemicals for use in food-contact applications since 1958. It judges safety based on models that estimate how much of a given substance might end up on someone’s dinner plate. If the concentration is low enough (and when these substances occur in food, it is almost always in trace amounts), further safety testing isn’t required.

Meanwhile, however, scientists are beginning to piece together data about the ubiquity of chemicals in the food supply and the cumulative impact of chemicals at minute doses. What they’re finding has some health advocates worried.

This is “a huge issue, and no [regulator] is paying attention,” says Janet Nudelman, program and policy director at the Breast Cancer Fund, a nonprofit that focuses on the environmental causes of the disease. “It doesn’t make sense to regulate the safety of food and then put the food in an unsafe package.”

How common are these chemicals? Researchers have found traces of styrene, a likely carcinogen, in instant noodles sold in polystyrene cups. They’ve detected nonylphenol—an estrogen-mimicking chemical produced by the breakdown of antioxidants used in plastics—in apple juice and baby formula. They’ve found traces of other hormone-disrupting chemicals in various foods: fire retardants in butter, Teflon components in microwave popcorn, and dibutyltin—a heat stabilizer for polyvinyl chloride—in beer, margarine, mayonnaise, processed cheese and wine. They’ve found unidentified estrogenic substances leaching from plastic water bottles.

Finding out which chemicals might have seeped into your groceries is nearly impossible, given the limited information collected and disclosed by regulators, the scientific challenges of this research and the secrecy of the food and packaging industries, which view their components as proprietary information. Although scientists are learning more about the pathways of these substances—and their potential effect on health—there is an enormous debate among scientists, policymakers and industry experts about what levels are safe.

The issue is complicated by questions about cumulative exposure, as Americans come into contact with multiple chemical-leaching products every day. Those questions are still unresolved, says Linda Birnbaum, director of the National Institute of Environmental Health Science, part of the National Institutes of Health. Still, she said, “we do know that if chemicals act by the same pathway that they will act in an additive manner”—meaning that a variety of chemicals ingested separately in very small doses may act on certain organ systems or tissues as if they were a single cumulative dose.

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,” says Thomas Neltner, director of a Pew Charitable Trusts project that examines how the FDA regulates food additives. “Unless someone in the FDA goes back and looks at those decisions in light of the scientific developments in the past 30 years, it’s pretty hard to say what is and isn’t safe in the food supply.”

“The whole system is stacked in favor of the food and packaging companies and against the protecting of public health,” Nudelman, of the Breast Cancer Fund, says. She and 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.

It’s not just consumers who lack information. The companies that make the food in the packages can face the same black box. Brand owners often do not know the complete chemical contents of their packaging, which typically comes through a long line of suppliers.

What’s more, they might have trouble getting answers if they ask. 

Nancy Hirshberg, vice president of natural resources at Stonyfield Farm, describes how in 2010, the organic yogurt producer decided to launch a multipack yogurt for children in a container made of PLA, a corn-based plastic. Because children are particularly vulnerable to the effects of hormone disrupters and other chemicals, the company wanted to ensure that no harmful chemicals would migrate into the food.

Stonyfield was able to figure out all but 3 percent of the ingredients in the new packaging. But when asked to identify that 3 percent, the plastic supplier balked at revealing what it considered a trade secret. To break the impasse, Stonyfield hired a consultant who put together a list of 2,600 chemicals that the dairy didn’t want in its packaging. The supplier confirmed that none were in the yogurt cups, and a third party verified the information.