“Sustainable design”, the philosophy of designing products to comply with the principles of social, economic, and ecological sustainability, has recently been gaining significant interest in the electronics industry. In addition to their continuing attention on reducing energy consumption, Original Equipment Manufacturers (OEMs) are placing greater restrictions on the use of halogens as flame retardant substances in plastics. This paper sheds some light on the requirements now being placed on high temperature plastics for terminal blocks, and we look at some of the possible solutions now available.