What is bisphenol A (BPA)?
Bisphenol A (or BPA) is a chemical substance used in the manufacture of polycarbonate plastics and epoxy resins. Polycarbonate plastic can be used for a whole host of products and foodgrade containers (including feeding bottles, medical and dental equipment, dental prostheses, etc). Epoxy resins have been used for over 50 years in the manufacture of lacquers traditionally considered suitable for food contact.
Why discuss this here?
Periodically, BPA comes to public attention. Currently there is much debate on this subject but up till now the scientific community has not yet expressed an official position. There are suspicions that in high concentrations, it could be harmful to human health.
In January 2010 the FDA published a document entitled “Update on Bisphenol A for Use in Food Contact Applications”, which is the latest document we have on the matter. We quote from the document: “FDA also recognizes substantial uncertainties with respect to the overall interpretation of these studies and their potential implications for human health effects of BPA exposure. These uncertainties relate to issues such as the routes of exposure employed, the lack of consistency among some of the measured endpoints or results between studies, the relevance of some animal models to human health, differences in the metabolism (and detoxification) of and responses to BPA both at different ages and in different species, and limited or absent dose response information for some studies.”
FDA has commissioned further studies from specialized agencies to address uncertainties raised by the general public, to support the transition to a more robust regulatory framework for BPA and to provide a rapid response and – if necessary – protect consumers .
What is the position of Weilburger Coatings regarding bisphenol?
Weilburger Coatings strictly abides by national and international standards for BPA use as well as FDA and EFSA regulations, pending the results of further studies and research.
BPA has been in use for over 50 years. In the United States alone it is estimated that BPA consumption for the manufacture of food contact materials is around 45,000 tons per year. In itself, this is a significant statistic, which we cannot fail to take into account: to date, no proof exists of potentially adverse effects to human health.
Are there any Bisphenol A free epoxy lacquers on the market?
In theory, it is possible to manufacture BPA-free epoxy-phenol interior coatings for aluminium packaging. However, up till now no manufacturer has succeeded in coming up with a reliable industrial solution for a number of reasons. Epoxy-phenol lacquers are well known for their exceptionally broad spectrum of chemical resistance to both acidic and alkaline products as well as to products containing organic solvents.
In actual fact, polyester-based lacquers combined with BPA-free phenol hardeners are available but their fields of application are very limited.
Furthermore, these lacquers have less chemical resistance, making them more liable to release monomeric and oligomeric substances. This gives rise to further concern regarding the overall migration limits of substances other than bisphenol A; in addition, their effects on the human body are not known as they have never been studied.
Moreover, many packaging manufacturers cannot handle production processes which differ according to the chemical composition of the various products the packaging is designed to contain; specific interaction also takes place between the material contained and the actual packaging. This makes it necessary to use well known and widely tested products of universal validity.
Another hypothetical solution to the problem is to use a so-called polymer purification process. In this case, the lacquers would be obtained from epoxy-phenol polymers with an almost zero BPA content, through a multi-stage process of substance extraction. However, this process is very expensive and would increase the cost of the raw material to up to five times higher than the current one, making it impossible to compete with standard epoxy products.