Is Your Old Water Filter Still Removing PFAS Effectively?

You probably installed a water filter to make your home safer and your water cleaner, but how do you know if it’s still doing its job? Specifically, is it still protecting you from per- and polyfluoroalkyl substances or PFAS, those invisible, long-lasting “forever chemicals” that have made their way into water supplies across the country?

PFAS are incredibly persistent in the environment and your body. These chemicals can cause a wide range of health concerns including thyroid issues, hormone disruption, and even certain cancers. Many home water filtration systems claim to remove PFAS, but if your filter is old or overused, it could be operating less effectively.

If you’re relying on a filter that hasn’t been changed in months or years, this is your wake-up call. Here’s what you need to know to determine whether your water filter is still capable of removing PFAS effectively, and what to do if it isn’t.

Understanding How PFAS Enters Your Drinking Water

Originally, PFAS played a role in manufacturing products like non-stick cookware, firefighting foam, stain-resistant fabrics, and even food packaging. Once introduced into the environment, they don’t break down. Instead, they seep into soil and groundwater, eventually finding their way into municipal water systems and private wells.

Even low levels of PFAS exposure can accumulate in your body over time because the body has a hard time getting rid of them. That’s why the EPA has set health advisory levels for certain PFAS compounds at nearly zero, meaning any detectable level in drinking water is a potential concern.

Removing these chemicals is where your water filter is supposed to help. However, not all filters are capable of handling PFAS, and even those that are can lose their effectiveness over time.

How Do Water Filters Remove PFAS?

The most effective filters for PFAS are whole-home water filtration systems, ion exchange resins, and reverse osmosis systems. Each of these technologies targets different chemical properties of PFAS compounds. A combination of these systems can work together to create a complete water solution for your home.

• Whole House Water Filtration: Eliminate PFAS before they ever enter your home, by filtering your entire water supply.
• Ion Exchange: Swaps out PFAS molecules with harmless ions, often used in more advanced filtration systems.
• Reverse Osmosis Water Filter: Uses a semipermeable membrane to block PFAS molecules entirely. It’s one of the most effective methods but often more expensive and requires professional installation.

Whichever system you use, its performance depends heavily on maintenance. That includes regular cartridge changes and proper system flushing. When you use a filter beyond its capacity, PFAS can slip through unnoticed.

Signs Your Filter May No Longer Be Effective

You can’t see PFAS. You can’t taste or smell them either. That’s what makes them so dangerous, and why relying solely on the look or feel of your water isn’t enough. Instead, you need to evaluate your filter system based on usage, age, and performance specs.

Here are some clear indicators your filter may no longer be protecting you:

• You’ve exceeded the manufacturer’s recommended filter lifespan. Most filters have a gallon limit or time frame (e.g., three or six months). Ignoring this recommendation drastically increases the chances of your filter failing you.
• You’ve noticed reduced water flow. This can indicate a clogged filter, which not only affects flow but may also force water through without proper filtration.
• Your filter isn’t certified for PFAS. Even if it’s working as intended, it may lack the ability to catch PFAS in the first place. Look for filters certified under NSF/ANSI Standard 53 or 58 for PFAS reduction.
• You live in an area with known PFAS contamination. If you haven’t updated your system in years, you may not have a system made to filter certain contaminants in your water. You may need to upgrade to a filter made to filter PFAS.

Why Filter Replacement Matters for PFAS

PFAS molecules are tiny, much smaller than common contaminants like chlorine or sediment. As your filter ages, the materials inside it degrade, meaning fewer PFAS molecules get trapped or exchanged. In some cases, saturated carbon filters can even start releasing captured contaminants back into your water, a process known as “breakthrough.”

PFAS accumulation in the body happens over time, and the damage they cause doesn’t always appear immediately. That’s why consistency and filter maintenance matter. A properly functioning filter can give you a healthier long-term outlook.

Even premium filters with high PFAS removal ratings are only effective when used properly and replaced on time. Skipping even one replacement cycle could open the door to unwanted exposure.

How to Choose the Right Replacement Filter

If it’s been a while since you’ve looked at your filtration system, now is the perfect time to assess your options. Before buying a new filter cartridge or upgrading your system, ask yourself:

• Is the filter certified for PFAS removal? Check for NSF/ANSI certifications that specifically include PFAS or PFOA/PFOS.
• What’s the recommended replacement cycle? Don’t guess. Check the manufacturer’s gallon limit or time frame and stick to it.
• Are you using the right filter for your area? If your local water supply is known to contain PFAS (check your city’s water quality report or well testing results), consider upgrading to a more robust system like reverse osmosis.
• Do you need whole-home or point-of-use filtration? For cooking, drinking, and bathing, point-of-use filters might not be enough. Shower water can also be a PFAS exposure source, especially for children or those with sensitive skin.

Why a Proactive Approach is Best

Replacing your water filter on time may seem like a chore, but it plays a critical role in keeping PFAS out of your body. If you’re unsure about your system’s effectiveness, you may want to consider professional testing or upgrading to a filtration system designed specifically for PFAS.

Some manufacturers also offer water filter subscription services that send replacements on schedule, taking the guesswork out of the process. If you’re managing a whole-home system, set calendar reminders or sign up for service alerts to stay ahead.

And if your system is more than a few years old or you’re using basic pitchers or faucet filters, now might be the time to invest in a higher-performance system that better handles today’s water quality challenges.

Protect the Water in Your Home

Your water filter is supposed to be your frontline defense against chemical contaminants like PFAS. But just like any protective tool, it loses power over time. Letting your filter go too long without replacement is like wearing a worn-out seatbelt; you might feel safer than you actually are.

Staying protected doesn’t have to be complicated. Check your filter’s specs. Replace it on schedule. Upgrade if needed. Your family’s health relies on water that’s not just clean, but safe from chemicals you can’t see.

So the next time you fill a glass or start the coffee maker, ask yourself: Is your filter really doing its job? If you’re not sure, it might be time to make a change.