Thermal Receipt Paper and BPA: Does Trader Joe's Understand the Trade-Offs?
According to a November 2017 Bloomberg news headline, the Trader Joe's grocery chain has decided "to Remove Controversial Chemicals From Receipts." In particular, as noted in its own announcement, Trader Joe's is "now pursuing receipt paper that is free of phenol chemicals (including BPA and BPS)."
As background, BPA (bisphenol A) and BPS (bisphenol S) have long been used as key components of the thermally reactive coating present on most transaction-receipt paper. As if by magic, white paper running through a thermal printer emerges in the form of a printed receipt, which the store clerk then hands you to confirm your purchase.
Of course, what happens inside the printer is not magic, but chemistry. Triggered by heat applied to the paper from the printer head, a chemical reaction occurs in the paper's coating to produce a non-ink printed image.
Three chemicals in the coating are responsible, each of which plays a critical role. One is a dye that is normally colorless but can be converted into a different and colorful chemical structure by reaction with a developer. Both BPA and BPS have commonly been used as developers. The chemical reaction is facilitated by a third chemical, known as a sensitizer. Although the functional descriptions are commonly used in this technology, all three are chemicals.
What is conspicuously missing from the announcement and story is how to replace BPA and BPS in receipt paper. Unless Trader Joe’s is resorting to magic instead of chemistry, BPA and BPS will be replaced with, you guessed it, another chemical.
Just a few years ago, the U.S. Environmental Protection Agency (EPA) released a report titled "Bisphenol A Alternatives in Thermal Paper." As described in this lengthy report, EPA scientists evaluated the health and environmental attributes of 19 potential alternatives to Bisphenol-A in thermal paper.
Despite diligently searching for a safer alternative, EPA came up empty-handed. Its researchers concluded that "[n]o clearly safer alternatives to BPA were identified in this report – most alternatives have Moderate or High hazard designations for human health or aquatic toxicity endpoints."
Following release of the EPA report, two studies on human exposure to BPA from handling receipt paper were published in the scientific literature. One study, from the U.S. National Toxicology Program, examined exposure to cashiers handling receipts throughout their work shift, which is far beyond any typical consumer exposure. The other study, from the Finnish Institute of Occupational Health, examined exposure in a group of volunteers simulating the work of a cashier.
The results from both studies indicate that even cashiers are not exposed to significant levels of BPA, and support the safe use of Bisphenol-A in thermal paper.
Trader Joe's choice to move away from BPA and BPS, while not supported by the science, is likely an effort to respond to popular market place trends. But as with any trade-off, it's important to understand what is the value, the benefit - and the safety - of what you have traded for.