In the packaging and converting sector, few issues have proved more controversial than the safety of bisphenol A (BPA). Major regulatory bodies, such as the European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA), maintain that
it is safe. Yet news stories continue to emerge that cause public disquiet.
Earlier this year, the FDA decided to ban the use of BPA in baby bottles and sippy cups, a year after the European Union took similar measures regarding polycarbonate feeding bottles for children under a year old. The FDA was quick to emphasise that its decision was not a policy reversal, merely the codification of what manufacturers were already doing - in 2009, six major US manufacturers stopped using BPA in domestically available baby bottles in response to customer concerns - but the seemingly mixed message did little for consumer confidence.
A few weeks ago, another study emerged that further complicates the issue. Published in the Journal of the American Medical Association, it suggested a possible link between BPA exposure and childhood obesity. This comes on top of previous studies that found a potential link between the chemical and body weight in adulthood. So what is BPA and why does the picture remain so confused?
BPA is a colourless, solid organic compound used in plastic food packaging and in the epoxy resin that coats tin cans. It has weak hormone-like qualities, mimicking the behaviour of oestrogen.
The chemical is ubiquitous. A study in 2011 estimated that detectable levels could be found in the urine of 90% of Americans. Most of it leaches into the body from packaging materials that have been washed, heated or exposed to stress.
Although many scientists believe that the small amounts found in packaging can be rapidly absorbed and detoxified by humans, others fear that persistent exposure could lead to negative health effects, ranging from impaired foetal and infant brain development to an increased risk of breast cancer.
Various pressure groups such as Healthy Children Healthy World (HCHW) have, according to Forbes, been bombarding packaging manufacturers with thousands of letters accusing them of putting the lives of children at risk.
The European Commission has decided to act. In February of this year, the Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids (CEF) asked the EFSA to conduct a sweeping re-evaluation of its position on BPA. Scheduled for completion by May 2013, the process will see EFSA revisit thousands of studies into effects of the chemical on the human body, from both dietary and non-dietary sources.
Dr Anna Federica Castoldi, a senior scientific officer with the organisation's CEF unit, is coordinating the process and is responsible for all EFSA work on BPA.
"In the initial opinion in 2006, the tolerable daily intake (TDI) of BPA was set at 0.05µg/kg of bodyweight," she says. "In 2011, we did another comprehensive review in which we confirmed the 2006 TDI, but the panel acknowledged that there were some uncertainties relating to the effects of BPA on the brain and immune system, and perhaps increased susceptibility to breast cancer for animals that experienced pre-natal exposure.
"These studies, however, had a lot of shortcomings and the relevance to humans could not be established. A lot of new toxicology studies have become available since," Castoldi claims.
This highlights how difficult it is to draw definite conclusions - changes may be observed, but proving what caused them is another matter. One study demonstrated a possible connection between BPA exposure and changes to the neurotransmitters of rats. But there was no way of confirming if this was the direct result of BPA exposure or purely adaptive. Other studies pertaining to the risk of breast cancer were similarly flawed.
"With some of the studies to do with increased neo-natal exposure to breast cancer, initial internal levels of BPA were not measured," Castoldi explains. "The animals were exposed orally through lactation, but it is known that the amount of BPA in milk is so low that the effects really are negligible. So, although these studies were good in some ways, there were details missing that were important to our interpretation. And you cannot base your opinion on something that is very partial."
With some manufacturers already moving away from BPA, if mainly for reasons of marketability, it is difficult to know how to proceed. Should producers err on the side of caution despite the views of regulatory bodies?
Nick Mullin, CEO of the Metal Packaging Manufacturers Association (MPMA), thinks not. The MPMA is a UK-based industry body, which has the main responsibility of representing and advising its members on operational, regulatory and environmental issues.
"In recent years, there have been many hundreds of studies undertaken into BPA, and its safety has been thoroughly evaluated by many authorities," he says. "The food supply chain is advised by these bodies and the advice is that BPA from food-contact materials does not represent a risk to consumers.
"One re-evaluation conducted as recently as November 2011 upheld its key conclusion that the existing TDI for BPA 'would protect all human populations from lifetime exposure to this substance through diet'."
The organisation's position is not just that its members should use EFSA standards as a guide, but that any move away from them might have serious repercussions. If the packaging industry strays from this standardised, peer-reviewed approach to safety, the number of potential hazards is likely only to grow.
"We have agencies across the world tasked with maintaining the well-being of our population," Mullin says. "These agencies tend
to err on the side of caution in their evaluations and assessments of food supply chain activity, and the sector operates within these regulatory measures. The question arises that if we move away from this process, where do we go? Who will be the arbiter of safe practice?"
Acknowledge and act
Campbell's, the food-manufacturing giant, took a different view - or so it seemed. Earlier this year, it was reported that the company was to phase out the use of BPA in the manufacturing of all its products.
Although this trend had been gathering pace in the plastics market, mainly in products designed for young children, Campbell's was the first major producer of canned goods to consider alternatives.
The decision was seen by many news sources as being a great example of customer opinion having a tangible effect on the behaviour of big corporations.
Respected publications such as Forbes and Business Week ran with the story, while Food Production Daily quoted an anonymous source with supposedly close links to Campbell's as saying the manufacturer is "estimating that the full switch to BPA alternatives will come about before 2015".
But these stories proved to be not all they originally seemed.
Like a number of other manufacturers, the company was to stop using BPA for some of its less acidic products. This is only around 5% of Campbell's total output - nowhere near as impressive as the initial story made out.
The company's vice-president of corporate social responsibility and sustainability David Stangis explained to Forbes: "Despite
what's been reported in the press, we're not there yet... We will move away [from BPA] when we find substitutes, but it's a long way off."
It transpires that the claim first emerged in a joint press release between the HCHW and a non-profit organisation called the Breast Cancer Fund. While Campbell's never backed up the claim, it didn't publicly refute it either, suggesting a desire to benefit from the positive press in the hope that no questions would be asked.
In reality, as Mullin points out, there is no one-size-fits-all alternative to BPA. For the time being, the best thing to do is to acknowledge the potential hazards and act accordingly.
"Current materials have been developed over decades to meet the needs of different production processes, manufacturing techniques and, most critically, the thousands of products to be contained," he explains. "The need is for non-technical bodies to defer to the regulatory authorities and to understand the fundamental difference between identifying a possible hazard and assessing the
risk associated with that hazard.
"For example, is water safe? What happens if instead of drinking one to two litres a day, 10 to 20L are consumed?" he posits. "Water can be hazardous, but we have effectively recognised and assessed the risk."
Sensationalism vs science
Meanwhile, the EFSA re-evaluation continues in earnest. In May this year, the body put out a public request for BPA migration data, receiving thousands of samples from member states and industry bodies. It also has an arrangement with the University of Parma, which monitors all new literature on BPA and filters out the most significant findings for examination. In the US, on the other hand, the FDA is carrying out an investigation of its own.
"The US has invested $30 million in new BPA studies," Castoldi says. "The FDA has recently finished a 90-day modified study into rats. The rats were not exposed for as long as they normally would be, but just through the pre-natal period.
"Now, this August, a huge carcinogenicity study has been started in which they will evaluate all the up-to-date toxicology research to see if there are any effects in this respect," she continues. "People are continuously trying to see if these uncertainties can be resolved."
The findings of the EFSA re-evaluation will be published in May 2013. Even if the opinion has changed and BPA is deemed
a hazard, certain areas of the global packaging industry are in no position to adapt.
For now, the important thing is to not allow hysteria and media sensationalism to get in the way of scientific fact.