Both epoxies and polycarbonates can have varying molecular weights depending on the manufacturing conditions. A common occurrence in the manufacturing of BPA-based epoxies or polycarbonates is the monomer not synthesizing completely which would leave some residual BPA monomer behind in the product. A breakdown of the final product can also occur. In the case of a breakdown of the polymer, certain conditions can cause the epoxy or polycarbonate to depolymerize when the material is under harsh environments or with aging during the service life of the material; during breakdown, the polymer “unzips” and becomes a free (i.e., discrete, non-polymerized). Both these occurrences can lead to excess of free BPA existing in the material and then possibly migrating from the epoxy or polycarbonate to other materials the product has been in contact with. It is for these reasons the use of BPA in manufacturing has been the source of debate and discussion in recent years.

As studies aimed at possible health effects of BPA are completed, and their results reviewed by regulatory agencies around the world, the overall safety of this compound is still in up for debate. Taking a look into the recent history of BPA, the European Food Safety Authority (EFSA) had established a tolerable daily intake (TDI) of 5 milligrams per kilogram of body weight per day for BPA in 2002. ¹  In January 2007 the EFSA set the TDI to 0.05 milligrams per kilogram of body weight per day due to a reevaluation of uncertainty factors in previously conducted studies.¹ However, in October 2008 the United States Food and Drug Administration (FDA) identified BPA’s no-observed-adverse-effect-level of 5 milligrams per kilogram of body weight per day which was the previous level set by the EFSA before reevaluation had occurred.²  Additionally, in July 2012, the FDA banned the use of BPA-based materials used to manufacture baby bottles as well as sippy cups in response to a petition from the American Chemical Council along with a follow up in July 2013 banning BPA-based materials in infant formula packaging .^{3, 4} The EFSA, in January 2015, reestablishing its new TDI of 4 micrograms per kilogram of body weight per day; however, it was concluded there were no current health concerns from dietary exposure for any persons at the time.⁵ Both the EFSA and FDA are continuing their investigations as new studies conclude and scientific evidence is collected, evaluated, and compared.^6,7

Regardless of industry, testing and evaluation of free BPA in products should not be considered any less vital even though current levels are seen as appropriate. Precise, accurate quantification of BPA in random sampling can provide a manufacturer with valuable information about the raw materials they receive and about their final products they export. International manufacturers of BPA based epoxies and polycarbonates must especially take regular testing into consideration due to the differences in tolerated exposure limits by the different regulatory agencies around the world. As long term studies conclude and the scientific merit evaluated by such regulatory agencies mentioned above, it does not appear the restrictions of BPA will loosen any time soon. Following the trend of the EFSA on their ever tightening TDI and the FDA banning the product in infant-geared products, it would seem that BPA will become more regulated in the future.