Bisphenol S (BPS) is a chemical compound that is commonly used as an alternative to bisphenol A (BPA) in the production of various consumer products, including thermal paper. Thermal paper is a type of paper that is coated with a chemical layer containing BPS or other similar compounds. The chemical coating on thermal paper, which often includes BPS, is responsible for the paper's ability to change color when exposed to heat. When heat is applied, the chemical coating reacts and produces a visible image, making thermal paper widely used in applications such as cash register receipts, labels, and tickets. However, the use of BPS in thermal paper has raised concerns due to its potential health effects. Studies have suggested that BPS may have similar endocrine-disrupting properties as BPA, which means it can interfere with hormonal systems in the body. BPS has been found to have estrogenic activity and can potentially disrupt the normal functioning of the endocrine system. As a result, there is growing interest in finding safer alternatives to BPS in thermal paper. Some manufacturers have started using other chemicals or developing BPS-free thermal paper to address these concerns.