In 2022, we tested 571 cash register receipts collected from U.S. stores, restaurants, gas stations, and other establishments. We identified the color developer--a chemical layer on the paper that allows for fast printing at the point of sale--on each receipt. We found bisphenol S (BPS) was by far the most common color developer. BPS has been marketed as an alternative to the well-known hormone disruptor bisphenol A (BPA), but evidence is mounting that its hazards are at least as concerning. Our study documented a reduction since 2017 in usage of bisphenol A-containing receipts and an increase in both bisphenol S and non-bisphenol alternatives.
Our identification of one of the alternatives, called NKK-1304, appears to be the first report in the scientific literature of this chemical in thermal paper. We were able to identify this chemical using information found in patent applications.
The study was published in October 2023 in the journal Environmental Pollution.
This study provides the first large survey of U.S. receipts in many years, filling a need for monitoring receipts, which have been demonstrated as significant sources of exposure to endocrine-disrupting chemicals, particularly for workers who handle them. Our data also revealed a significant difference between national retailers versus regional and local retailers in the trend away from bisphenols. Large, national retailers were more likely to be using bisphenol-free alternatives. In contrast, small retailers had mostly stopped using BPA but most frequently had chosen BPS as the alternative.
Our study also showed that a relatively inexpensive and rapid technique, infrared spectroscopy, successfully identified receipt chemicals. Most studies on chemicals in receipts and other uses of thermal paper (such as labels on packaging) have relied on more expensive and time-consuming analytical methods.
Citation: Gillian Zaharias Miller, Daniela Tapia Pitzzu, Melissa Cooper Sargent, Jeff Gearhart, "Bisphenols and alternative developers in thermal paper receipts from the U.S. market assessed by Fourier transform infrared spectroscopy." Environmental Pollution v. 335, 15 October 2023, 122232