Concentration of bisphenol A in thermal paper

Bisphenol A (BPA) is widely used as a color developer in thermal paper. Thermal paper is ubiquitous in daily life due to its use in cash register receipts, so opportunities for human contact abound. For this study, 10 blank cash register receipts were obtained from businesses in suburban Boston. BPA was extracted and analysis of concentration was performed using gas chromatograph/flame ionization detector. In some receipts, BPA was not detected but in others it was as high as 19 mg for a 12-inch long receipt, which is in line with concentrations indicated in patents. This study is intended to highlight the potential for human exposure to BPA as well as the ease with which exposure may be reduced through the use of BPA-free thermal paper.