Bisphenol S (BPS) is an organic compound with the formula (C6H4OH)2SO2. It has two phenol functional groups on either side of a sulfonyl group. It is commonly used as a reactant in epoxy reactions, and is used in curing fast-drying epoxy resin glues. Bisphenol S has become commonly used as a plasticizing agent following the widespread bans on the use of the related compound bisphenol A due to its estrogen-mimicking properties, and bisphenol S can now be found in a variety of common consumer products. However, bisphenol S has been shown to have similar estrogenic activity to bisphenol A, and so its main advantage in these applications is merely that it escapes the legal prohibition on bisphenol A and allows products containing bisphenol S to be labelled "BPA free". Bisphenol S is used in curing fast-drying epoxy glues, and as an anticorrosive. It is also commonly used as a reactant in polymer reactions.