BPA and its analogues in thermal papers: an assessment of presence and dermal exposure

Abstract

Thermal papers are a significant source of exposure to bisphenol A (BPA) and other phenolic compounds (PCs), absorbed through the skin via dermal contact. This study analyzed thermal paper receipts from various commercial settings in Türkiye to assess BPA and its structural analogs. For both deterministic and probabilistic risk assessments, the estimated daily intake (EDI), hazard quotient (HQ), and hazard index (HI) were calculated for the general population and workers exposed via dermal contact from handling thermal receipts. The results showed that BPA and bisphenol S (BPS) were the most frequently detected chemicals (detected in 99% and 100% of samples, respectively) with concentrations ranging from 1.98–1061 μg per g paper and 0.070–210 μg per g paper in thermal paper receipts in Türkiye, respectively. The EDI of PCs based on the mean concentration determined in the samples for the general population ranged between 0.00000184 μg per kg per day and 0.000445 μg per kg per day, whereas it ranged between 0.0000919 μg per kg per day and 0.022 μg per kg per day for occupational exposure of workers. The EDI value based on the mean concentration detected in samples was 0.000445 μg per kg per day and 0.00223 μg per kg per day for the general population and occupational exposure, respectively. Exposure to BPS was lower, resulting in exposure values of 0.000039 μg per kg per day and 0.002 μg per kg per day for the general population and occupational exposure, respectively. Although these mean concentration based exposure levels are below the U.S. EPA reference dose (50 μg per kg per day for BPA), they exceed the more stringent European Food Safety Authority (EFSA) total daily intake (TDI) limits set for BPA (0.0002 μg per kg per day) in some cases, indicating potential health risks. The HQ and HI analyses further underscore the risks, particularly for workers, with HI values surpassing safe thresholds. The study calls for stricter regulations on BPA and its analogs in thermal papers due to the significant risks, even from BPA-free products that use BPS as a substitute.