The gold standard for years has been copper pipe, with its only known drawback from a heath standpoint being the lead based solder that was used in the joints until 20 years ago when it was banned. Those living in older homes should have their water tested to see if lead is a problem. Plastic pipe such as PVC (polyvinyl chloride, used for cold water only), and CPVC (chlorinated polyvinyl chloride, used for both hot and cold water) have been around for years, and both are approved for use with drinking water. Neither can be described as environmentally friendly from a production or recycling standpoint, however, and the glue used to join them together contains some strong solvents as well. There is some concern about the leaching of chemicals that can give water a plastic taste, though the taste usually improves after a few months. Safety issues are mainly considered a concern in PVC pipe that was manufactured before 1977. While I’ve not seen any compelling evidence of the health risk of drinking water from PVC or CPVC plumbing, there is always the possibility that something will turn up in the future. Flexible PEX (cross-lined polyethylene, used for both hot and cold water) tubing is becoming the pipe of choice for plumbers today, since it’s easy to install. It, too, can impart a plastic taste to water that goes away with time, but since it isn’t glued together, there are fewer toxic solvents used in installing it. PEX tubing, PVC pipe, and CPVC pipe marked “NSF-61” or “NSF-PW” indicate that they have passed testing for potentially harmful chemicals leaching into the water.
