“Epoxy resin has been around for some 40 years, and is not so easy to replace,” said Dominique Fort, AkzoNobel ‘s marketing director for coatings. It is not only the performance of BPA-containing coatings that have been optimised over time, but also their cost. He added: “Many of the components of BPA-NI coatings have been proven, but they are still not mainstream. I think that until industry makes the full transition to the new coatings, you will see a cost impact.”
Some commentators have talked about that impact in terms of a premium of up to 10% compared with traditional coatings. This is because the first generation of BPA-NI solutions uses a range of raw materials, none of which is produced on anything like the scale seen with BPA. These are then combined to create multiple variants in relatively small volumes, each tailored to a different coating role.
Paying more while getting less
To make matters worse, customers are paying more while getting less. One industry expert explained: “The lower performance of BPA-NI coatings has forced can makers to reduce the claimed shelf-life of products in their cans.” In the worst cases, this could mean a cut in declared shelf-life from three-years in epoxy-coated cans to less than one year in first-generation BPA-NI coated cans. Many of these coatings are based on polyester or acrylic.
So what has driven the move towards BPA-NI alternatives, given their drawbacks? Over a year ago, France unilaterally banned the use of direct food-contact BPA. No safe threshold or specific migration limit (SML) was given. Since then, the move has affected can makers and their customers outside as well as inside France.
Earlier this year, coatings supplier PPG estimated that no fewer than seven can plants in England and Wales had partially converted to BPA-NI options.
When regulators in California added BPA to the Proposition 65 list of substances requiring a warning on product packaging or as an emergency stop-gap measure at point-of-sale, this also helped to shift perceptions in Europe. The Californian requirements came into effect this summer.
Rescind its national ban
Meanwhile, the European Commission has proposed an SML for BPA. The hope is that, once established, this would allow France to rescind its national ban.
Adding to the challenges is the fact that several key components of first-generation BPA-NI coatings are under heavy scrutiny in North America and Europe. Fort added: “Today it’s BPA, tomorrow it will be other substances styrenes in California or formaldehyde in the EU.” Formaldehyde has already been designated a ‘substance of concern’ in the EU.
Among the second-generation solutions currently under development are spray coatings based on polyethylene and polypropylene that have none of the food-contact issues of some other substances.