Bisphenol S, a New Bisphenol Analogue, in Paper Products and Currency Bills and Its Association with Bisphenol A Residues

As the evidence of the toxic effects of bisphenol A (BPA) grows, its application in commercial products is gradually being replaced with other related compounds, such as bisphenol S (BPS). Nevertheless, very little is known about the occurrence of BPS in the environment. In this study, BPS was analyzed in 16 types of paper and paper products (n = 268), including thermal receipts, paper currencies, flyers, magazines, newspapers, food contact papers, airplane luggage tags, printing paper, kitchen rolls (i.e., paper towels), and toilet paper. All thermal receipt paper samples (n = 111) contained BPS at concentrations ranging from 0.0000138 to 22.0 mg/g (geometric mean: 0.181 mg/g). The overall mean concentrations of BPS in thermal receipt papers were similar to the concentrations reported earlier for BPA in the same set of samples. A significant negative correlation existed between BPS and BPA concentrations in thermal receipt paper samples (r = -0.55, p < 0.0001). BPS was detected in 87% of currency bill samples (n = 52) from 21 countries, at concentrations ranging from below the limit of quantification (LOQ) to 6.26 mu g/g (geometric mean: 0.029 mu g/g). BPS also was found in 14 other paper product types (n = 105), at concentrations ranging from 88%). To our knowledge, this is the first report on the occurrence of BPS in paper products and currency bills.