Bisphenol S (BPS) is an organic compound with the formula (HOC6H4)2SO2. It has two phenol functional groups on either side of asulfonyl group. It is commonly used in curing fast-drying epoxy resin adhesives. It is a bisphenol, and a close analog of bisphenol A(BPA) in which the dimethylmethylene group (C(CH3)2) is replaced with a sulfone group (SO2).