An article published on November 28, 2018, by regulatory news provider Chemical Watch focused on how “a major can coatings producer has worked with other stakeholders to develop an alternative to bisphenol A-based epoxies.” This article was originally published within the Business Guide to Safer Chemicals: Fourth Edition produced by Chemical Watch (FPF reported).
Thomas Mallen, technical director at Sherwin-Williams Packaging (formerly known as Valspar), estimated that for a long time “about 80% of metal packaging” used coatings made of epoxies based on bisphenol A (BPA, 80-05-9). However, BPA has now been placed on the EU’s list of substances of very high concern (SVHCs) due to its Category 1B reprotoxic properties (in January 2017, FPF reported), as well as “endocrine disrupting properties which cause probable serious effects to human health” (in June 2017, FPF reported) and “endocrine disrupting properties causing adverse effects to the environment” (in January 2018, FPF reported).
These and other regulatory changes signify “a clear regulatory drive towards removing BPA from the epoxies used in can coatings,” Mallen said. However, for a number of “technical, regulatory and societal” reasons, substituting BPA “without making compromises of safety, performance and high speed application” is “hugely challenging.”
To address these problems, Sherwin-Williams scientists “borrowed the concept of ‘Safety by Design’ from the pharmaceuticals industry,” applying it in particular to demonstrate the absence of endocrine activity for the molecules proposed as BPA replacements. The monomer used in the new epoxy coating product developed by the company is tetramethyl bisphenol F (TMBPF, CAS 5384-21-4) (FPF reported). This chemical was shown to not produce any estrogenic effects in both in vitro and in vivo tests (FPF reported). However, a later study revealed anti-estrogenic and anti-androgenic activity of TMBPF in vitro (FPF reported). An assessment published by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) in August 2017 concluded that, due to “significant lack of data,” the agency is currently “unable to rule out” potential endocrine activity of TMBPF (FPF reported).
Mallen explained that “one of the key things for us to develop trust between the stakeholders in society was to be transparent and put all the material from us and others on a dedicated website.” He further commented that “we feel like we met the challenge, although of course the journey continues.”
Chemical Watch (November 28, 2018). “BPA could get canned.”
Melody M. Bomgardner (March 5, 2019). “How a new epoxy could boot BPA from cans.” Chemical and Engineering News
Soto, A. et al. (2017) “Evidence of Absence: Estrogenicity Assessment of a New Food-Contact Coating and the Bisphenol Used in Its Synthesis.” Environmental Science and Technology. doi: 10.1021/acs.est.6b04704 (published January 18, 2017)