Comparing Plumbing Pipe Materials
PVC (polyvinyl chloride) is the most widely used pipe material, followed by iron, copper, and ABS (acrylonitrile-butadiene-styrene), another common type of plastic used in drainage pipes. New polyethylene and polypropylene products are more eco-friendly but less widely available. How do they all compare in materials, energy inputs and lifespan?
Iron and copper: Metal pipes often have high levels of recycled content, and are easily recycled. However, even recycled metal pipes are energy-intensive. Melting and forming copper and iron products at extreme temperatures consumes more energy than the production process for plastic pipes.
Metal pipes are stronger and more crack-resistant, but they also corrode faster, adding potentially dangerous residues to water. Werea KIMAB, a European corrosion and metals research institute, estimates iron drainpipes have a 50-year lifespan. However, epoxy pipe linings add up to 50 years of life to metal pipes while also improving the water quality by adding a barrier between the water and corroding metal.
PVC: Hard plastics are largely made with raw petroleum-based chemicals, and discarded pipes mostly end up in landfills. Some PVC products can be recycled, but recycling is expensive and the market demand is low because virgin PVC is cheap. However, environmental costs may be high. Greenpeace and other environmental groups oppose all use of PVC, which they say emits possibly harmful chemicals throughout production, use, and disposal. The Uni-Bell PVC Pipe Association estimates PVC pipes will last 100 years under normal conditions if properly installed.
Other plastics: Polyethylene and polypropylene are generally less toxic. Aquatherm, a German company, makes polypropylene pipes that are listed as GreenPeace International's only "future-friendly" plumbing product. These alternative plastics are more easily recycled, even though most available products do not have recycled content -- and they need to be replaced faster than PVC or lined iron. Aquatherm claims a 50-year lifespan for its pipes.