Toxic linings in cans
A key health issue surrounding canned food is the use of a substance called Bisphenol-A (BPA) which is used in the lining on the inside of cans or lids to stop the metal contaminating the food. Unfortunately, BPA itself can leak into the food.
BPA is an endocrine-disrupting chemical, meaning that it has potentially deleterious effects on reproduction and brain development. It is primarily used in the production of polycarbonate plastics and epoxy resins, which have many uses, from CDs and medical devices to impact-resistant safety equipment and dental sealants.
In 2015, the European Food Safety Authority (EFSA) published the results of a re-evaluation of BPA carried out by one of its expert panels. This review found that BPA “poses no health risks to consumers because current exposure to the chemical is too low to cause harm.”
However, the EFSA also significantly lowered the estimated safe level (tolerable daily intake or TDI) to 4 micrograms per kilogram of body weight, although this is temporary pending the outcome of a long-term study into the pre- and postnatal effects of BPA exposure.
The EFSA’s study found that public exposure to BPA is “well below” the new TDI of 4 µg/kg of body weight per day, with the highest estimated exposure being 3-5 times lower than the new TDI. Dietary exposure is highest among infants and toddlers, given their higher food consumption per kilo of bodyweight, but this is still more than four times below the new TDI.
A person would have to ingest more than 400 µg of BPA per kg of body weight per day to cause adverse kidney and liver effects. However, the EFSA said that effects of BPA on the reproductive, nervous, immune, metabolic and cardiovascular systems, as well as in the development of cancer “are not considered likely at present but they could not be excluded.”
Choosing BPA-free packaging does not necessarily mean consumers are avoiding potentially harmful chemicals. A recent study by a consortium of North American non-profit organisations tested 192 cans from a range of companies and found four coating types besides BPA in use: acrylic resins, oleoresin, polyester resins and polyvinyl chloride (PVC) copolymers.
The report described these as “regrettable substitute[s]” as several of these are known or potential carcinogens, including PVC and polystyrene:
We know very little about the additives used in these compounds to give them the properties that make them stable and effective can linings. Our research does demonstrate that there are multiple formulations of most of these compounds, but there is no way to determine the specific chemicals used or how they are produced ... the lack of safety data and unknown additives mean we have no reliable data attesting to the safety of [several of] these compounds.
Where do the companies stand?
Most of the companies in this guide have no policy on the use of BPA in their food packaging. Only two brands, Mr Organic and Essential, were totally BPA-free, while Biona and Kraft Heinz are partially BPA-free.
||Uses BPA or no policy
In its response to Ethical Consumer’s company questionnaire, Suma explained why it continues to use BPA in its cans:
“We currently use BPA as a lining in our cans following advice from the European Food Safety Authority. Independent studies have shown that, even when consumed at high levels, BPA is rapidly absorbed, detoxified, and eliminated from humans. The government advises that the levels of BPA found in food from food contact materials are not a concern to health. We continue to monitor developments in food safety and technology and are looking at possible alternatives.”
When asked about the use of BPA in its cans, Waitrose replied:
“BPA is only permitted for use in Waitrose-branded canned goods where its presence in protective coatings and linings is critical in ensuring product safety. The use of BPA in this application will be phased out as developments in packaging technology provide a viable alternative. Testing of canned product containing BPA-based protective coatings and linings is carried out to demonstrate that any migration of BPA into the product is within statutory limits.”
Essential Trading stated that it did not intentionally use BPA in its canned goods and glass jar lids. Essential Trading prefer the term ‘BPA non-intent’ because “BPA is ubiquitous in the natural environment, and very small amounts may be detected in non-BPA substances, as current technology measures in parts per billion.”
If you’re concerned about BPA or other undisclosed chemical linings of cans, you can choose baked beans in glass jars from Biona, Bionova and Essential. The advantage is that the use of BPA is minimised – unfortunately, it may still be used to line the metal lid of the Biona and Bionova brands.
- Buy Mr Organic or Essential BPA-free baked beans
- Buy baked beans in glass jars from Biona or Bionova
- Reduce the number of tinned goods you eat
- Make your own baked beans – plenty of recipes on the web
The problems with tin
‘Tin’ cans are, in fact, largely made out of steel. However, to prevent oxidation, the steel is often covered with a fine coating of tin, creating a material called ‘tinplate’.