Plastic Packaging for Food: Life-Saver or Life-Raider?April 15, 2013
Plastic food wraps and containers offer convenience, re-usability, and protection from grime and disease. They also pose invisible threats to our endocrine systems and our health. We are increasingly aware that chemicals in the plastics that contact our food slip into our bodies. How does this migration occur? Should we be worried about contamination from our food containers? And what can we as citizens and food-serving businesses do to protect ourselves?
Answers to the second two questions don’t come easily for consumers because so much is still unknown about the toxicity and make-up of the plastic materials that surround us. But a number of recent studies and publications are shining lights on the effects of food-containing plastics on our environmental and public health. For example, Susan Freinkel’s Plastic: A Toxic Love Story presents a clear and readable account of the infinite ways plastics have infiltrated our daily lives and what this means. The answers in this post draw primarily from Freinkel’s book, which I recommend to anyone as a great introduction to the remarkable and tragic history of our addiction to plastics. I’ve also drawn some info from an upcoming Rapid Response report on Sous Vide cooking by PPRC’s own Michelle Gaither. (we’ll post the Rapid Response report later this week).
How does plastic get into our food?
Plastics are tremendously variable (forgive me, plastic) substances. At the heart of this variability lies a host of additives that plastic manufacturers blend with polymers to give plastics desired properties. Additives in food packaging serve as antioxidants, stabilizers, plasticizers, lubricants, anti-microbials, and heat resistors, among other things. Additives that are lightly bound to polymers can escape, or drop off a polymer’s complex daisy chains, when these chains contact enough heat, light, or other destabilizing forces. When released, some chemical additives are drawn to fats. This tendency makes fatty foods – like cheeses, meats, and oils – common sources of our exposure to toxic plastic substances.
Should we worry?
We know that some additives interfere with our fragile hormonal regulatory systems. These so-called “endocrine disruptors” introduce noise into the symphony of hormones controlled by our endocrine system. Endocrine disruptors can enhance or block the production of hormones that are crucial to our sexual development, metabolism, and cognitive function. Studies suggest that exposure to these chemicals can cause early-puberty in females, reduced sperm counts in males, altered functions of reproductive organs, obesity, and increased rates of some breast, ovarian, testicular, and prostate cancers (Yang, et al. 2011). Unlike most other known toxins, the toxicity of endocrine disruptors does not simply increase with increased doses of the toxin. Studies like Vandenburg et al (2012) suggest that low-dose exposures can have dramatic effects. These effects depend not only on the dose but on the timing of exposure. Therefore, expectant mothers, in-utero babies, and young children are uniquely susceptible to endocrine disruptors.
Over the last few decades, a few additives – namely bisphenol-A (BPA) and phthalates – have caught the attention of researchers, regulators, and media for their endocrine disrupting effects. BPA is used in rigid plastic like polycarbonate (typically labeled number 7). While manufacturers advertise “BPA free” containers, we still don’t know the safety of current replacements for BPA additives. You can get a more detailed breakdown on BPA and its alternatives from a recent Rapid Response report on BPA exposure from receipts. Phthalates are typically used as plasticizers to make vinyl plastics, like polyvinyl chloride (PVC), more pliable. Many phthalates, like di(2-ethylhexyl)phthalate (DEHP), have known associations with kidney, liver, and reproductive harm.
Some good news – sort of – is that the FDA regulates, or at least tries to regulate, plastic containers and materials that come into contact with food. For FDA approval, plastics manufacturers (of Food Contact Substances) submit their products to tests that measure chemical migration at temperatures that the container or wrap is likely to encounter during ordinary use. However, scientists don’t know enough about the toxicity of many of the additives we encounter to determine whether or not these chemicals are safe for us in the long run. The FDA maintains an inventory of additives approved as safe for their intended use. But this list currently includes controversial chemicals like phthalates and BPA. So one could argue that FDA “approval” does not hold much weight. In addition to contacting media-flagged chemicals (currently being scrutinized by the scientific community), we contact hundreds of additives that we know little or nothing about because researchers haven’t yet studied their toxic effects. A recent study (Yang et al., 2001) suggests that many of the 455 commercially available plastic products – even some widely considered safe by manufactuers and the FDA, such as high-density polyethylene (HDPE) and low-densitypolyethylene (LDPE) – leach additives when exposed to stress.
Consumers and businesses are often powerless to find out exactly which chemicals exist in the plastic cookware they buy. Under our current chemical regulatory system, manufacturers generally are not required to list the ingredients of their materials. When asked for ingredients lists, some manufacturers are unwilling to provide them. Such blockades to accessing information about plastic constituents harms our ability to regulate potentially harmful toxins. Before toxicologists can assess the toxicity of any plastic container, they need to know which polymers and additives make up a product.
Such ongoing uncertainties are scary. As Freinkel suggests, we are all lab rats in a tremendously large experiment on the long term effects of low-level barrages of plastic toxins. To an extent, we need to accept that we are now all “part plastic.”
What can we do now?
But does this mean we should all just sit around and see what happens, or which health affects arise? As Freinkel suggests, no way. Consumers and businesses aren’t powerless in the face of invisible toxic threats. We can make important decisions to minimize our exposures. Check out The Ecologist’s quick guide to storing food safely in plastic containers to see which types of containers are safe and which ones to watch out for. Here are a few tips that anyone can follow to protect against unwanted exposure:
Avoid microwaving or heating food in plastic containers.
Avoid PVC (#3) containers, food wrap, and juice bottles.
Avoid (#7) containers for food contact use. (#7) includes several resins, one of them being polycarbonate. Some polycarbonates may still be manufactured with BPA.
Avoid storing plastic water bottles in hot places like the backseat of your car. Instead use refillable bottles.
Avoid cooking in “turkey” or oven bags.
As for businesses working with Sous Vide packaging or plastic films, Michelle Gaither provides a few legal and good-practice tips. Businesses should:
Demand disclosure of SV packaging material, or disclosure of ingredients.
Demand safer plastics from suppliers.
Allow PPRC to conduct a preliminary review of toxicity data and endpoints of the constituents. PPRC is able to assist businesses in this manner under our Rapid Response service.
What can we do in the long term?
Finally, as Freinkel and chemical law specialists like John Wargo point out, the most effective way to protect ourselves from the harmful effects of plastic toxins would be to change our current chemical regulatory system. Rather than rely on the current framework of chemical management, which deems chemicals “innocent until proven guilty,” consumers and businesses could help demand a more precautionary and preventative approach to approving chemicals for production. Demanding more producer accountability and labeling of chemicals in polymer products would help scientific testing of worrisome plastic toxins proceed more quickly and effectively. Changing a regulatory system, however, takes a lot of time and work. It requires viable and agreeable political and scientific alternatives.
Do you have suggestions about how to avoid potentially harmful plastic food packaging? Or do you know of any tips or resources for consumers and businesses who want to ensure they are using safe plastic products? Please let us know what you think in the comments.
-Cyrus Philbrick, Communications Manager
and Michelle Gaither, Industrial Engineer