Raina Pang
Feb 3, 2012

Would you like a side of chemicals with that? The health risks of food contact substances

We’ve all been there…Starving at a gas station convenience store, eyeing the sandwiches in the refrigerated section. Is that egg salad sandwich safe to eat? At this moment, you may only be weighing the potential for food poisoning against your growling stomach. However, consumers may be getting more from packaged foods than they bargain for from food contact substances (FCS).

FCS include the materials used during manufacturing, packing, packaging, transporting and holding food. Because these materials can leech into food during contact, it is important to ensure that they are safe for human consumption. Regulations regarding FCS arise from the food contact notification program run by the food additive safety branch of the Food and Drug Administration (FDA). The current procedure for approval of a new FCS is detailed in Title 21 of the Code of Federal Regulations  and requires a “reasonable certainty in the minds of competent scientists that a substance is not harmful under the intended conditions of use” (21 CFR 170.3(i)).

So what is considered a “reasonable certainty”? Well, the required studies showing reasonable certainty depends on the expected individual daily exposure. Around 85 percent of FCS have an estimated daily individual exposure under 150 micrograms. These compounds only require short term in vitro genetic toxicity studies. This means, that  to be considered safe, the majority of the packing materiel that comes into contact with our food only needs to prove not carcinogenic to cells in a dish. Only FCS with estimated daily consumption greater than 150 micrograms a day require in vivo subchronic chromosome tests. For these studies, animals are fed a substance for three months to see the health effects. Depending on these preliminary tests, additional studies may be required to assess toxicity to the nervous system, embryos, fetuses and reproductive organs.

While the procedures of the food notification program should safeguard against the excessive consumption of harmful chemicals via food packaging, research consistently emerges suggesting that many common FCS may be damaging to our health.

One compound receiving attention over purported health effects is bisphenol phosphate A (BPA). BPA is used to harden polycarbonate plastics, make epoxy resin and line food and beverage containers. Despite a wealth of safety related studies (over 5000!) regarding BPA, the debate over the health effects of BPA remains contentious. In 2010, the FDA acknowledged some “uncertainties” in the health effects of BPA. Instead of banning the substance, the FDA committed to spending millions of dollars conducting follow up studies on the safety of BPA. The National Resource Defense Council (NRDC), however, felt that the current assessment of BPA shows that this substance poses a health risk and should be banned. After an ignored petition, the NRDC filed a lawsuit against the FDA seeking to ban the use of BPA. This lawsuit has prompted the FDA to agree to make a decision about BPA by March 2012, but some suggest that a full ban is unlikely.

Regardless of the FDA’s decision on BPA, reducing individual exposure may be important. A recent study conducted at Harvard University shows BPA levels dramatically increase after consumption of canned food. Individual measures to reduce BPA exposure include limiting consumption of canned and processed food; buying processed food in cartons, pouches or glass; using BPA free reusable bottles; and avoiding dental sealants made from BPA and receipts, which can be coated with BPA.

Perflourinated compounds (PFC) have also been featured in the news recently for reported negative health effects. PFCs are commonly used in food packaging, such as microwave popcorn bags, for their stain and stick resistant properties. These compounds break down slowly and can contaminate drinking water, food and food chains. Animal studies suggest that PFC exerts toxic effects on the immune system. To investigate the effect of these compounds on human immune response, Phillippe Grandjean and colleagues at Harvard compared antibody response to childhood vaccines in children exposed to high levels of PFC and those with low exposure. Response to vaccines is a good way to estimate immune function because immunizations expose a standardized dose of a virus at a standardized age. After vaccination, children with high PFC exposure showed reduced antibody response, which sometimes remained below the threshold required for long-term protection. This study shows that high exposure to PFC can be damaging to the immune response, but it was not undertaken in a way that could directly access the risk of PFC exposure from FCS versus general environmental exposure. In any case, studies such as this highlight that PFC exposure should be limited. Individuals can reduce their exposure to PFCs by avoiding microwave popcorn and non-stick pans and using glass containers to microwave food.

Emerging research suggesting commonly used FCS may cause negative health effects opens the door for new innovative food packaging solutions. Nanomaterials, which are being offered as a solution to a diverse range of scientific problems such as water filtration and drug delivery, hold potential as new FCS. Potential uses for these materials include barrier protection to prevent spoiling and food packages that can detect spoilage or contamination. While nanomaterials appear promising in food packaging, it is important to emphasize the establishment of the safety of these materials before we implement their use.

The debate over the safety of food packaging looms large. Current safeguards into how our food is packaged may miss important long-term health effects of FCS. The slow response to health effects of FCS means that consumers need to remain aware of emerging research on the potential health implications associated with FCS and make individual protective decisions, as if we don’t already have enough to worry about when it comes to food choices!