Polyvinyl chloride, or PVC, undergoes a hardening process known as thermosetting before it begins its life as a common plumbing pipe material. This process gives the substance a hardy resistance to numerous chemicals, including bleach and even harsh drain openers. In short, it is safe to use bleach on PVC pipe, but you'll benefit in the long run if you know the basics "dos" and "don'ts" of treating PVC with various types chemicals.
There are numerous reasons to apply bleach to PVC pipe. You can use household bleach, or sodium hypochlorite, to clean external PVC pipes. Commonly, household bleach serves as a drain opener for clogged pipes; you can pour bleach down the drain to combat clogs without worrying about the safety of your PVC pipes, though you should always run warm water down the drain afterward. Bleach also remedies algae growth on the inside and outside of PVC pipes.
Though PVC resists 100-percent sodium hypochlorite well, using diluted bleach or a bleach solution is an even safer bet – polyvinyl chloride has excellent chemical compatibility with solutions containing 20 percent or less sodium hypochlorite. Dilute liquid bleach with water when cleaning PVC pipes externally. You can safely use calcium hypochlorite, bleaching powder, on PVC pipes as well.
Other Safe Chemicals
PVC has a very strong chemical resistance, which makes it ideal for use in chemical storage tanks, drainage systems and sewage systems. Polyvinyl chloride has good to excellent chemical compatibility with ammonia, a common ingredient in household cleaners. You can also use cleaners such as soda ash and borax, or sodium carbonate and sodium borate, on PVC pipe safely. Many chemicals that find themselves down the drain – such as citric acid, detergents, dyes and glucose – have no ill effects on PVC pipe.
Though generally resilient, PVC's chemical composition isn't infallible. Chemicals such as acetone and phenol, used in nail polish remover and paint strippers, can have severe effects on PVC pipes. Avoid applying any chemicals from the ethyl group – including ethylene bromide, ethylene chloride or ethylene chlorohydrin – to PVC pipes. Never pour lacquers, pine oil, sulfuric acid or turpentine down drains connected to PVC pipes.