Butyl 3-mercaptopropionate (BuMP) by Bruno Bock is butyl 3-mercaptopropionate. Acts as a chain transfer agent. It is a clear, in short optical path colorless liquid with characteristic odor. Butyl 3-mercaptopropionate (BuMP) reacts like other mercaptanes and possesses longterm stability. Butyl 3-mercaptopropionate (BuMP) is incompatible with oxidizing agents. Used in the manufacturing of certain polymers.