PEX manufacturers fortify the material against chlorine by adding antioxidants during the manufacturing process that protect PEX from chlorine. However, these antioxidants are “sacrificial” in that they are consumed by the action of neutralizing chlorine's impact on the pipe.
Since the mid-2000s, testing according to ASTM F2023 is a mandatory requirement for all PEX cold- and hot-water plumbing tubing, as per tubing standards ASTM F876 and CSA B137. 5. As a result, PEX tubing has proven to be a reliable piping material for chlorinated potable water applications.
Chlorine degradation of PEX occurs when the chlorine in drinking water, which is added to keep it clean and safe for human consumption, attacks the PEX piping, breaking down molecular bonds, resulting in micro-cracks that gradually expand to the point of a pipe failure.
Note that we do not recommend using PEX Tubing with Chemicals at temperatures over 180°F. Although PEX Tubing is considered fully resistant to many chemicals, we recommend a reduction of the maximum pressure applied at 180°F to 80%.
However, there has been controversy over the validity of the chlorine resistance test (ASTM F2023). Therefore, we recommend only using PEX pipe with the highest chlorine resistance rating (5) no matter what your pipe is used for, even cold water.
PEX pipes are very thick but they are still susceptible to rodent damage that can cause pipes to crack or break. Possible Leaching: Although uncommon, some homeowners and plumbing companies have reported a few PEX pipes leaching harmful contaminants like BPA (Bisphenol A) into the water supply.
As recommended by the Chlorine Institute's pamphlet 6 “Piping Systems for Dry Chlorine”, all pressurized piping should be seamless carbon steel, grade B, Schedule 80, type S, ASTM A- 106.
Material Concerns: One of the primary concerns about Pex plumbing is the material itself. While Pex pipes are undoubtedly flexible, making them easier to install in tight spaces, they are not as durable as traditional materials like copper or even PVC.
PEX Pipe Class Action Lawsuits
A number of manufacturers, including Uponor, Viega, Nibco and Zurn, have already been sued over their PEX piping products.
PEX A offers higher burst resistance, capable of withstanding up to 500 PSI in extreme cold, while PEX B, being more rigid, is less resilient.
The more chlorine in the water the more corrosion. This has a corrosive effect on the inside of the pipes and slowly erodes the piping over time. Eventually, chlorine eats all the way through the pipes and creates pinhole leaks, which if left unchecked, can cause a myriad of problems within the home.
PEX: Due to its flexibility and durability, PEX piping should last at least 50 years. PVC / CPVC: Under typical conditions, these pipes should last up to 100 years. Keep in mind that PVC pipes are often used for drainage because extreme heat can damage them.
4 – Bleach can damage pipes.
Bleach reacts with metal and is very corrosive, with rust or oxidation caused by the trading of electrons between the metal and bleach molecules. Copper pipes can also be damaged making them more prone to plumbing leaks. With PVC pipes, bleach dissolves the sealant used around the pipes.
Common Causes of PEX Pipe Failures
In addition, extreme bends and kinks place a very high local stress on the wall of the pipe, making it more susceptible to oxidative degradation. This is especially true in southern climates where water chlorine levels run high.
Bacteria
In extreme cases, the bacteria caused by moisture can penetrate inside the PEX pipes and contaminate the water.
The problem with PEX seems to be that it's contaminated -- it leaves the factory with chemicals used in its manufacture still on the pipe. In time it cleans up, but during that time those chemicals are going into the water.
Most research suggests that PEX isn't ideal for drinking water. Filtering water from PEX lines makes it safe for consumption. Most homeowners stick to other pipe options for water supply lines, like copper.
PEX pipes may be prohibited in certain places if they don't meet safety standards. For example, PEX plumbing was banned in California before 2010. Now, PEX pipes are legal but come with mandatory use standards to ensure safety. Check with your city and state to find out if PEX is legal in your area.
Based on this analysis, the PEX pipe material examined appears to have good resistance to chlorinated water. References 1. USEPA.
PEX pipes are the top option for plumbing in Florida. But that doesn't mean you should automatically pass up a house that uses other materials.
PEX Pipe Is Vulnerable
Rodents Chewing Through PEX Pipe is a common problem in our area. It doesn't matter how old your home is, if you have an attic, you need to watch for rodent damage to PEX Pipe or PVC. If you're hearing rustling noises coming from the attic, it's time to do an inspection.
PEX manufacturers fortify the material against chlorine by adding antioxidants during the manufacturing process that protect PEX from chlorine. However, these antioxidants are “sacrificial” in that they are consumed by the action of neutralizing chlorine's impact on the pipe.
AISI 316L stainless steel and resistance to chlorine compounds for disinfection. AISI 316L stainless steel used for Eurotubi pressfittings and pipes offers increased resistance to treatments with chlorine-based compounds, provided that the prescribed doses are respected.
PVC and CPVC. In addition to holding up well in the short term, PVC and CPVC have the best long-term resistance to chlorine. Chlorine is rarely if ever, the cause for failure or breakdown with these types of pipes, and other causes are likely to cause issues before chlorine does.