DMPT (dimethylparatoluidine)is an amine accelerator that gives very short gel times. An amine accelerator accelerates the curing process of polyester and vinyl ester with BPO. The possible disadvantages of amine accelerators are that they give limited potlife, give a yellow to brown colour after curing and are sensitive to UV light at cured stage. In some cases, dimethyl paratoluidine serves as a promoter. A promoter gives a shorter gel time and faster curing, which is desirable in production with short cycle times such as: injection, pressing and polyester concrete. A promoter should also be used when working with thin layer thicknesses.