Tris(2-chloroethyl) phosphate (TCEP) is a chemical compound used as a flame retardant, plasticizer, and viscosity regulator in various types of polymers including polyurethanes, polyester resins, and polyacrylates.

[2] Because of its suspected reproductive toxicity, it is listed as a substance of very high concern under the European Union's REACH regulations.

Its use has been largely replaced by tris(chloropropyl) phosphate, which is safer.

[3]