The chemical compound BPA (bisphenol A), commonly used in plastic products, has been controversial for years due to its adverse health effects. KU Leuven researchers have developed a BPA alternative with similar functionality that has no harmful effects on health or the environment.
From lunch boxes, reusable water bottles and cutting boards to snuffle mats for dogs and children’s bibs, anyone searching online for "BPA-free" products will be spoilt for choice. BPA-free means the product does not contain bisphenol A, an indispensable building-block chemical for the production of plastics and additives found in countless products. However, there’s currently no fully functional substitute for bisphenol A, and products labelled BPA-free may still contain other harmful bisphenols.
The use of this chemical has long been the subject of debate. The European Chemicals Agency (ECHA) has listed BPA as an endocrine disruptor and reproductive toxicant. The use of BPA has already been partially restricted in drinking bottles and cups for babies and toddlers, and in food packaging for children up to the age of three. In April, after extensive research, the European Food Safety Authority (EFSA) set a new, much stricter tolerable daily intake level (or TDI) of 0.2 nanograms per kilogram of body weight per day. The newly established TDI is 20,000 times lower than the previous one.
Alternative with similar properties
The Sustainable Catalysis and Engineering research group at KU Leuven is exploring potential substitutes. "The chemical structure of BPA has a few notable strengths: it makes materials very strong and heat-resistant. That’s why it’s used in so many products," postdoctoral researcher Laura Trullemans explains. "The challenge is to maintain these properties while avoiding harmful effects on health and the environment."
The researchers developed alternative molecules preserving the core structure of BPA while supplementing other chemical compounds. "In tests on human cells, we have observed that our alternatives significantly reduce or completely eliminate hormonal activity," Trullemans points out. "Even when present in high concentrations, the chemical substances we have developed hardly bind with hormone receptors. Materials made with our BPA alternative are of the same quality as BPA-based materials."
Safe as well as sustainable
Not only are the new chemicals more environmentally-friendly, but the chemical process is also greener. "Our process differs from current BPA production methods as we avoid using any toxic substances. What’s more, the high yield generated by our process, coupled with the reuse of reagents, results in much less waste. This allows us to optimise yields in a sustainable way," says Professor Bert Sels, head of the research group. "In addition, it’s possible to produce our safer molecules using bio-based materials. The combination of safety and sustainability, also referred to as "safe and sustainable by design," stands as an explicit EU objective."
The research is currently being conducted on a laboratory scale, meaning practical implementation will still take some time. "We will conduct additional tests to ensure the safety of the molecule," Bert Sels points out. "In addition, we need to increase the scale of production, optimise the sustainability of the production process and investigate its use in specific applications. The use of BPA and other bisphenols is likely to be further restricted in the future. So the need for a fully functional alternative is urgent."
Bregt Van Hoeyveld, translated by Yente De Moor