Why Is PEX Plumbing Bad? (Or Isn’t It?)

Since its rise to popularity in the ‘80s and ‘90s, PEX plumbing has continued to steal the spotlight, serving as a go-to pick in new construction. It’s flexible, making it easy to install and resistant to freezing and bursting.

Key Points:

  • PEX plumbing is a popular choice due to its flexibility, easy installation, and affordability.
  • However, PEX tubing is sensitive to UV light, non-recyclable, and susceptible to bacteria and rodent damage.
  • PEX is also incompatible with chlorine, which can cause the tubing to weaken and develop leaks over time.

On top of that, it’s inexpensive, requires few tools to install, and doesn’t demand dozens of joints throughout a single system. Given its benefits, it’s no surprise that it’s popular.

But is PEX plumbing a bad choice for your house?

The answer can be yes or no, as every situation is different. We’re here to explain, so continue reading to learn more!

What Is PEX Plumbing?

Cross-linked polyethylene, better known as PEX, is a popular material used for tubing. The material is flexible and easy to install, making it a go-to pick for DIYers.

While it’s often used for plumbing applications, it’s also a standard in various heating and cooling systems, like radiant floor heating. In addition, folks can use it to insulate electrical wires and cables.

PEX usually comes in red, white, and blue rolls, with red used for hot water, blue used for cold water, and white used for either.

What Is Wrong With PEX Plumbing?

1/2" Brass PEX Fittings, 15/30/45/90 PCS PEX Fittings, 5/10/15/30 Each Elbow TEE Straight Couplings, Crimp Cinch, PEX Brass Crimp Fitting Combo with 1/2" Tees"T", 1/2" Elbows, 1/2" Straight

While PEX plumbing is undeniably convenient due to its flexibility and easy installation, it has a few downsides. It isn’t suitable for every application, so while it might be ideal for some situations, it might be a lousy pick for others. Here are a few downfalls of PEX piping:

Light Sensitivity

Although PEX is decently durable, it crumbles in direct sunlight (literally). When the material is exposed to UV rays, like those in sunlight, it degrades faster.

UV light consumes the chlorine-inhibiting antioxidants added to offer better chlorine resistance, leaving the material defenseless against chlorine-induced oxidation and susceptible to damage.

Eventually, the material begins to break down as the chlorine ramps up the brittle oxidative failure of PEX. When this happens, the tubing will weaken, leading to ruptures and leaks throughout the system.

Due to this sensitivity, PEX is only suitable for underground or indoor applications without exposure to UV light.


Like most plastics, PEX tubing isn’t recyclable. So, when the PEX piping system in your home develops leaks or bursts, you’ll need to get rid of it. Of course, you can replace the damaged section with a new stretch of PEX, but you can’t recycle the old material if you’re replacing the entire system.

Unfortunately, the lengths of tubing you discard have nowhere to go. So, until someone develops a way to dispose of plastic, the tubing goes to the same place as other plastics.

Susceptible To Bacteria And Rodents

While the flexibility and plastic nature of PEX lends well to various applications, it can be a drawback when it comes to bacteria and rodents. While failure due to bacteria is very rare, it can happen.

This scenario usually occurs when PEX tubing is buried deep in the ground, where it’s susceptible to surrounding groundwater. The bacteria, which enjoy the abundant groundwater, can penetrate the PEX tubing and contaminate the water flowing through.

Aside from bacteria, PEX is susceptible to attacks from rodents. The flexible material makes for an easy target, allowing the cunning creatures to nibble holes in the tubing for easy water access. Their sharp teeth easily chomp through the material, so PEX is no match for them.

This is a common problem in homes with rodent issues, so if your home has a rodent problem, it’s essential to correct it. Otherwise, your plumbing system might end up with leaks after the rodents gnaw through the plumbing lines.

Incompatible With Chlorine

The water we get from public water systems is usually chlorinated. While the U.S. Environmental Protection Agency (EPA) regulates chlorine to a specific level to ensure its safe for human consumption, its presence isn’t ideal for PEX.

The two don’t mix well, as chlorination affects the durability and longevity of PEX tubing. The chlorine content in the water flowing through PEX tubing accelerates the brittle oxidative failure of the material, eventually leading to leakage and bursts.

Since this is a known problem, many manufacturers began adding antioxidants to combat the failure. However, while the additions help, they only slow down the process slightly. The antioxidants act as a barrier, which eventually degrades, giving the chlorine in the water access to the tubing material.

Is PEX A Bad Choice For Plumbing?

PEX Pipe 1/2 Inch Flexible Water Pipe 2 Rolls of X 100 Feet Tubing Red / Blue Potable Water Pex Tubing

While PEX tubing has its drawbacks, this is typical of every plumbing material. It’s essential to consider your situation, as every scenario is different. While PEX might work perfectly for one home, it might not be ideal for another.

It isn’t necessarily bad, but it might not be ideal for all situations. If you’re unsure whether PEX is a good choice for your home, we recommend consulting your local plumbing for advice specific to your situation.

Is PEX Pipe Unsafe?

PEX pipes are relatively new, with only around 35 years of use in the United States. While the material has been around for longer than that, the material has only been an option in the United States for approximately three and a half decades.

Given its short presence in the U.S., researchers haven’t had the opportunity to evaluate the material over the long run.

However, a recent study completed in 2021 evaluated eight types of PEX pipe brands. In this study, researchers discovered that 62 chemicals leached into water flowing through the pipes. Approximately half of those organic compounds that ended up in the water are considered toxicological but not carcinogenic.

So, the possibility of leached chemicals is there, and while they’re not carcinogenic, they can be toxicological. That said, this is only one study, so it’ll likely take more research to conclude whether PEX is a suitable fit.

Plus, the study disregarded other factors, like the types of fittings used, synergistic effects, and disinfection byproducts.

As of now, PEX isn’t entirely safe, but it’s not wholly unsafe, either. If you’re concerned about the potential leaching, avoid using the tubing for water lines supplying drinking water.

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