Whether we are storing, transporting, or heating it up, our food routinely contacts plastic. Are all plastics the same? Absolutely not! Some plastic products may look the same – hard or flexible, soft or brittle – but they could contain very different chemicals and have varying levels of safety.
Bisphenol A (BPA) is a controversial chemical used in the manufacture of several plastic products and coatings. Mounting research is finding that this once seemingly harmless chemical has been leaching into the oceans, affecting wildlife, and sometimes threatening human health through direct and indirect exposure.
BPA does not occur naturally in the environment; humans invented it nearly 120 years ago. The manufacturing industry has been using it since the 1940s to make epoxy resins that coat the inner lining of food and beverage cans (to protect food from being in direct contact with metal) and in the packaging of microwaveable and other pre-packaged or processed foods.
Some dental sealants contain BPA and manufacturers use it in the production of polycarbonate, a hard plastic often used for eyeglass lenses, exterior automobile parts, electronic parts, sporting equipment (e.g., helmets), and medical devices. Up until very recently, manufacturers often used polycarbonate to make baby bottles and cups, water bottles, and other food storage containers. Due to new scientific findings, public outcry, and government regulations, fewer of these products are now in the North American marketplace. Polycarbonate baby bottles currently fall under Canada’s Hazardous Products Act, which now prohibits their importation, advertisement, and sale.1
A significant but lesser-known application of BPA is in the coating of carbonless paper used in cash register receipts, for example.
So What’s the Problem with BPA?
In 2008, Health Canada’s Food Directorate released a statement that it had, “concluded that the current dietary exposure to BPA through food packaging uses is not expected to pose a health risk to the general population, including newborns and infants.”2 However, in 2010, Canada became the first country to declare BPA a toxic substance.
Like some other chemicals, BPA mimics the main female hormone, estrogen, which living cells could mistakenly interact with, as though it were the real thing. BPA can leach out of packaging and bottles into food, especially when heated. A recent Statistics Canada survey found that 91% of Canadians have BPA in their bodies.3 Research during the past twenty years has shown that exposure to BPA early in life may lead to premature puberty, prostate problems, breast cancer, and behavioural conditions.4,5
To improve the accuracy of exposure estimates, the Government of Canada is monitoring BPA in packaged foods through the analysis of a number of recent and ongoing studies.6,7,8
In a small Canadian study recently published in Environmental Health Perspectives, researchers evaluated the impact of switching to a fresh foods diet from one that includes packaged foods.9 Urine levels of BPA fell by 66% when the study participants consumed a fresh foods diet, confirming the researchers’ hypothesis that dietary intake is a major source of BPA exposure. These results suggest that it is possible to limit one’s exposure by increasing consumption of fresh foods and by choosing smart food storage methods. It also shows how efficient the body is in eliminating BPA.
Despite the body’s ability to flush BPA fairly quickly, research shows that continual exposure can cause harm. Very recent studies traced the source of BPA found on paper money to carbonless cash register receipts, which often come into contact with money. This suggests that we are exposed to more BPA from other sources (by being absorbed through the skin) and for longer durations than previously thought.10,11
BPA from discarded plastic products can also leach out into the ocean and soil and eventually affect humans and wildlife.A survey of twenty countries, recently presented at a meeting of the American Chemical Society, found that BPA levels in ocean water and sand were at levels many times higher than what Health Canada has deemed safe, and significantly higher than what previous research has found.12
How to Minimize Exposure in a World of BPA
Determining thresholds of safety and estimating the level of human and environmental exposure to BPA have been contentious issues for decades now, with non-industry studies often finding significantly higher levels of exposure and safety risks compared to studies led by the plastics industry. In addition to choosing fresh foods over packaged ones, to reduce your exposure to BPA, the Government of Canada further recommends that you use non-polycarbonate plastic containers to heat food and liquids, or use alternative materials such as glass, ceramic, or stainless steel. If you do use polycarbonate, then allow hot substances to cool before pouring them into the containers.
You might also avoid unnecessary exposure to BPA by minimizing hand contact with receipts and washing your hands after contact with paper money or carbonless cash register receipts. It is wise to keep these items – and other no carbon required (NCR) paper – from children.
The Society of the Plastics Industry, Inc. (SPI) developed a coding system to simplify the process of sorting and recycling plastic (not to indicate safety). Any plastic product with a code from 1-6 was manufactured without BPA. BPA falls under code 7 (other), but since this code is a catchall for any type of plastic that does not fit into categories 1-6, you cannot assume that a product contains polycarbonate or BPA just because it has that code. The new eco-friendly biodegradable plastics also fall under code 7. Polycarbonate plastics often also include a “PC” label. Unfortunately, the law does not require plastics manufacturers to mark SPI codes on products, and many do not include them at all. If you are uncertain, contact the product manufacturer.
To learn more about BPA and the latest information on this ongoing issue, visit the Health Canada website, www.hc-sc.gc.ca.
|Adapted from The Society of the Plastics Industry, Inc. (SPI)|
|SPI Code13,14||Type of Plastic||Uses/Products|
|1||Polyethylene terephthalate (PETE or PET) Nickname: polyester. Degrades with repeated use and can allow bacteria to develop. Sometimes contains traces of BPA.||Used for soft drink bottles, food packaging (e.g., condiment bottles, packaged food coverings, and containers for use in the oven), and non-food containers; also recycled into products like polyester fibres for filler, carpets, clothing, and other textiles.|
|2||High Density Polyethylene (HDPE)
|Usually used for food products with a short shelf life, such as milk and juice, as well as water and industrial cleaning supplies (laundry detergent, bleach); shampoo and cosmetics packaging; hard plastic containers and grocery bags; imitation wood; playground equipment; also recycled into similar products.|
|3||Polyvinyl Chloride (PVC) Vinyl (V)Sometimes contains toxic chemicals called adipates and phthalates (i.e., plasticizers), used to soften the plastic. They can leach out when this plastic contacts food.||Shrink-wrap, non-food packaging, shower curtains, lawn furniture, window frames, flooring, pipes, fencing, children’s toys and teethers, medical tubing/instruments, coatings, and more; also recycled into similar products.|
|4||Low Density Polyethylene (LDPE)||Laboratory equipment, food and non-food bags (e.g., produce, bread, dry-cleaning, garbage bags), buckets, toys, flexible lids and bottles, wires and cables, dispensing bottles, tubing, various moulded laboratory equipment, film products, injection moulding, heat-sealing applications, coatings for paper milk cartons and hot/cold beverage cups; also recycled into shipping envelopes, garbage can liners, floor tile, furniture, etc.|
|5||Polypropylene (PP) High melting point.||Condiment bottles, yogurt and margarine containers, medicine bottles, reusable coffee mugs and lids, automotive products (bumpers, interior trim), non-food packaging, industrial fibres; also recycled into similar products.|
|6||Polystyrene (PS) Low melting point.||Styrofoam® food (meat trays, egg cartons, clamshell containers) and non-food packaging, toys, flower pots, cafeteria trays, plastic utensils, insulation board, other Styrofoam® products; also recycled into similar products.|
|7||Other Plastics Includes polycarbonate (which contains BPA); the majority of code 7 plastics are not polycarbonate; includes biodegradable plastics and plastics made from a combination of plastics in codes 1-6.||Including acrylic, acrylonitrile butadiene styrene, fiberglass, nylon, polylactic acid bottles, plastic lumber applications, headlight lenses, and safety shields/glasses; also sometimes recycled into bottle and lumber applications.|