Plastics are used in the delivery of utilities to our homes often in hidden ways. Underground pipes and ducting which may have previously been made of metals or ceramics are being replaced by plastics such as medium density polyethylene. The synthetic alternatives have some flex so will not break if there is any slight ground movement, they will not corrode over time, and are coloured to indicate their different uses. Blue (1) is for water pipes and yellow 2 for service and mains gas and. Other colours include black - domestic mains electric cable, low voltage; red - high voltage electric cables; green - broadband, telephone, and non-motorway CCTV cables; grey - BT or telecommunications cables; purple - motorway service cables for speed cameras, traffic cameras, emergency phones etc; and orange - street lighting and traffic signalling cables.
The 500 series bath taps (3) were designed by Martyn Rowlands for IMI Opella Ltd in the 1960s. They were the first all plastic taps and won a Design Award in 1966. They are made of polyacetal which is highly dimensionally stable and is wear, impact and shock resistant.
Polyvinyl chloride (PVC) is used to cover electrical cable in many applications as it provides waterproofing and electrical insulation. This example of a cable (4) is for domestic or industrial use, the wires are sheathed in coloured PVC which identifies their function. The brown live wire carries electricity to the appliance, socket, or switch, whilst the blue neutral wire transfers electricity away from the appliance to avoid overloading.
Electrical plugs, sockets and switches have had many shapes and forms since the introduction of domestic electricity in the 1890s. If the house did not have enough sockets, appliances were even plugged into light fittings (5). The standard 3 pin plugs and sockets, as we know them in the UK today, were introduced in 1947. Until that point multiple forms were used at the same time (6-10). Before 1992 appliances were sold without a pre-wired plug, but due to many incidents resulting in injury and deaths, the law was changed meaning electrical goods had to be sold with attached plugs and resulting in the introduction of moulded plugs (11). This helps to prevent harm but makes it more difficult to mend broken appliances.