Our food, it seems, is always touching plastic. Plastics play a part in every phase of food production and preparation. Food gets processed on plastic equipment, and packaged and shipped in plastic-lined boxes and cans. At home, we store and reheat the leftovers in plastic containers.
As for that strange plastic taste in last week's lo mein -- that's just the aftertaste of convenience. It couldn't possibly be harmful, right?
Recent health controversies have spawned new discussions about the safety of plastics in the food industry. In particular, research that's found potential health risks from bisphenol A (BPA), a common chemical in food packaging, has many concerned.
"For many years, the plastics incorporating BPA were believed to be safe," says Anila Jacob, MD, senior scientist with the Environmental Working Group, a nonprofit advocacy organization. Now that there are many questions about BPA, "that does raise broader questions about the safety of plastics in general," Jacob tells WebMD.
Plastics make getting, eating, and storing food more efficient. But are they also making us sick?
Plastic in Food: Inevitable Transfer
It's long been known that infinitesimal bits of plastic get into our food from containers. The process is called "leaching" or "migration." The chemical industry acknowledges that you can't avoid this transfer, noting on its web site that "[v]irtually all food packaging materials contain substances that can migrate into the food they contact."
The amounts are small, says Laura Vandenberg, PhD, postdoctoral fellow in biology at Tufts University in Boston. "But almost any plastic container can be expected to leach trace amounts of plastics into food," she says.
Heating food in plastic seems to increase the amount that's transferred to food. Migration also increases when plastic touches fatty, salty, or acidic foods. How much actually gets into our bodies? Vandenberg says that to her knowledge, there's no research that can answer that question.
Although most of the chemicals making the culinary crossing are considered "safe," Jacob tells WebMD that's generally not because they've been proved safe, but rather they haven't been proven to be unsafe.
"There is very little published research on the potential adverse health effects of chemicals that leach from plastic food containers, so it's difficult to say they're safe with any degree of certainty, especially with long-term use," says Jacob.
Two suspects are under active investigation: bisphenol A and a class of chemicals called phthalates.