So, too, is a 2022 National Institute for Occupational Safety and Health animal study showing dermal (skin) absorption by PFAS leading to immune system dysfunction.
Known to cause many serious health problems, including cancer, PFAS are not regulated in the U.S. So unfortunately, it’s up to you to protect yourself from these forever chemicals.
One way you can do that is by filtering the water you use at home, as much as possible.
When it comes to drinking water filters, you have many choices, and they do not filter water equally well. So how can you be sure your water filtration method removes PFAS?
In this article, we compare the efficiency of all major types of water filters for eliminating PFAS. Although PFAS removal is not your only concern when it comes to clean drinking water, it’s a major one. Fortunately, water filters that trap PFAS will also remove other harmful chemicals.
Our handy table on water filters that remove PFAS will guide your purchasing decision so that you can make the best choice for you and your family.
Table of Contents
- What Are PFAS?
- What Products are PFAS In?
- Are PFAS Bad for Health?
- Are PFAS Regulated in the United States?
- How to Remove PFAS from Water at Home
- US EPA-Approved Water Filters That Remove PFAS
- 1. Granulated Activated Carbon (GAC)
- 2. Anion Exchange Resin (AER)
- 3. Reverse Osmosis Filters & Nanofiltration
- What About Water Distillation for PFAS Removal?
- Pros and Cons of Water Filtration Methods That Remove PFAS
- Final Thoughts on Water Filters That Remove PFAS
This article includes affiliate links, which means we may earn a commission if you decide to make a purchase.
Editor’s Note: I don’t believe that it should be up to individuals to spend money filtering chemicals that corporations have dumped into our environment in order to protect their health. But unfortunately, that’s our current reality. All water filtration methods come with a cost of some sort, and I know that not everyone can afford a high-quality filter.
If you have the means, I believe it’s worth the investment. If you don’t have the means, keep in mind that in most cases, any water filter is better than no filter at all (as long as you’re actually changing out the membranes when they’re full). Remember to do the best you can, even if it’s not perfect.
What Are PFAS?
Per- and polyfluoroalkyl substances (PFAS), aka “forever chemicals,” is the common name given to a huge chemical family dating back to the 1930s when they were first made in the lab. Currently, there are estimated to be roughly 12,000 different kinds of PFAS (maybe more; no one is quite sure).
All PFAS contain one or more atoms of the element, fluorine, attached to carbon atoms. The fluorine-carbon bond is one of the strongest in nature. It is not easily broken. This is why PFAS are called forever chemicals. They persist in soil, air, water, and living organisms, building up over time, mostly unchanged.
Two PFAS in particular, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), were commonly used to make other PFAS. Teflon is the most well known PFAS made this way.
Because of their harmful effects, PFOA and PFOS have been banned in the United States since 2015. They have largely been replaced by a mixture of PFAS called GenX. Unfortunately, GenX is no better; in fact, it can actually be more toxic than its banned cousins.
What Products are PFAS In?
PFAS are popular chemicals because they repel both water and oil. Who doesn’t like non-stick, stain-free, crease-free, or smudge-proof? You can find PFAS in:
- Firefighting foam
- Camping gear
- Clothes and underwear
- Food packaging
- Non-stick cookware
- Carpets and furniture
- Personal care products
Are PFAS Bad for Health?
There are many serious health effects associated with PFAS. For instance, based on human and animal studies, here are only a few of them:
- Testicular, bladder, or kidney cancer
- Thyroid dysfunction
- Non-alcoholic fatty liver disease
- Weakened response to vaccines
- Reduced fertility
- Birth defects
Are PFAS Regulated in the United States?
You may be surprised to hear that it wasn’t until 2016 that the United States Environmental Protection Agency (US EPA) established a non-enforceable lifetime health advisory of 70 parts per trillion (ppt) for combined PFOA and PFOS in drinking water.
Remember: PFOA and PFOS are just two out of 12,000+ different kinds of PFAS. This means public water utilities do not have to treat water for PFAS contamination.
Finally, in March 2023, the US EPA proposed a national primary drinking water regulation for six PFAS in drinking water. They set the maximum at only 4 ppt for:
- Mixture of PFNA, PFHxS, PFBS, and HFPO-DA (GenX)
The lowered standard is an acknowledgement of how toxic PFAS are. Only the most sophisticated labs can even measure something so small. (To give you an idea, 1 ppt is equivalent to one drop of water in 20 Olympic-sized swimming pools!)
If passed as predicted by 2024, public utilities must meet enforceable standards called Maximum Contaminant Levels (MCLs). This means they must notify residents if MCLs are exceeded and take steps to become compliant.
Since PFAS are still widely used, they will be present in drinking water. In fact, it’s estimated by the USGS that almost half of all Americans use water that is contaminated with PFAS. Up to 75% of rural households and 25% of urban dwellings are at risk.
Those on private wells need to be especially aware of the hazard.
Here is a graphic showing PFAS results from the USGS testing sites.
You can explore the Environmental Working Group’s interactive PFAS map (current as of June 2022) to find out if your town or city already has water contaminated with PFAS.
How to Remove PFAS from Water at Home
A chemical truth about PFAS is that they dissolve in water where they’d stay indefinitely unless you took action to remove them. Whether you receive water from a public utility or rely on a well, PFAS contamination is possible.
Unfortunately, inexpensive filters including Brita or Pur do not remove PFAS from drinking water… Many don’t even reduce PFAS.
Before you invest in an expensive home water filtration system, you may hear that it’s a good idea to get your water tested for PFAS by a professional lab—if you can afford it. Testing for a dozen PFAS could cost $400 on up.
If your water doesn’t contain those tested for, but does have a few of the other 12,000 PFAS in existence, you may get a false sense of security. And to make matters worse, tests do not even exist for all PFAS.
Additionally, remember that water testing is a one-time occurrence. Since water contamination profiles change regularly— maybe daily—it’s possible to get negative results for PFAS on the day of the test. Yet if you would have waited a day or two, that result could have been positive. Yikes!
So what’s the best course of action?
Since PFAS are so ubiquitous, assume your home water is contaminated. In which case investing in a filtration system becomes totally justified.
US EPA-Approved Water Filters That Remove PFAS
The United States Environmental Protection Agency (US EPA) has done studies on the most effective drinking water filtration systems that remove PFAS. Here’s a brief rundown on the US EPA-approved methods followed by a summary table of highlights.
(FYI: US EPA maintains a drinking water treatability database with updated, referenced information on more than 120 contaminants and over 30 filtration methods.)
1. Granulated Activated Carbon (GAC)
Adsorption refers to the physical attachment of PFAS in the millions of tiny nooks and crannies in activated carbon. Powdered activated carbon is not effective at adsorbing PFAS.
With this method, filters placed where you use water (like the kitchen and bathroom) are more effective than filters placed at the main water line into your home. The reason is water could pick up PFAS already in your home from adhesives used to join pipes via joints.
A pre-filter to trap larger contaminants before they reach GAC is the optimal setup to minimize GAC saturation from them, leaving GAC open to adsorbing smaller but hazardous contaminants such as volatile organic chemicals (VOCs) or PFAS.
An advantage of GAC over other methods is that 99.99% of it can be regenerated through heat with PFAS destroyed in the process. That recycled GAC can later be reused.
According to federal regulations, if spent GAC contains hazardous substances, (like PFAS are proposed as being), it must be regenerated in a National Sanitation Foundation-certified regeneration facility only.
Today, this regeneration occurs on industrial levels only, even though some sources appear to suggest that a home oven operating at 200℉ will work. (Please don’t attempt this. Inquire if a company selling a home GAC system you’re thinking of purchasing will allow you to send back spent filters for regeneration.)
Today, regenerated GAC is used for non-potable purposes such as wastewater treatment.
Although the US EPA doesn’t include activated carbon block filters (like Boroux—formerly known as Berkey—or Epic Water Filters) as an effective way to remove PFAS from drinking water, it seems they theoretically could work, too.
Carbon block filters consist of pulverized and compressed activated carbon granules glued together with a purported food-grade binder of unknown identity. Often, they are positioned before a sensitive reverse osmosis (RO) filter (see below for more about RO) to trap larger contaminants, allowing the RO membrane free to catch smaller molecules.
Sometimes, carbon block filters are impregnated with resins (plastic beads) to function like an ion exchange-activated carbon system (see below for more about ion exchange). In this case, it’s difficult to know which filtration method is capturing the PFAS.
Boroux (which used to be called Berkey), for example, seems to be using a carbon block filter to capture some types of PFAS, while using “a proprietary blend of 5 other media” to capture other types of PFAS. While it’s not clear exactly what this priority blend is made up of, it does include impregnated ion exchange plastic beads, which help filter out the PFAS that can’t be filtered by the carbon block.
If in doubt, inquire about any aspect of the filtration system before purchasing it. Incidentally, given the dual nature of this filter, it seems recyclability or regeneration would be impossible.
Many sources state coconut shell is the best form of carbon for PFAS removal as GAC or as carbon block. However, independent testing shows agglomerated bituminous coal removes some PFAS that will slip through coconut carbon. Most sources agree coconut activated carbon is more expensive than coal.
Granulated activated carbon filters are effective at removing PFAS depending on many variables such as:
- Type of carbon used (bituminous coal is best)
- Depth of the bed of carbon (more the better)
- Flow rate of the water (keep it slow)
- Amount and type of other pollutants present (often hampers adsorption, but this is out of your control)
Practically, this can make buying a GAC water filter difficult because they’re not all created equally. Some GAC water filters are much more effective than others at removing PFAS.
2. Anion Exchange Resin (AER)
In water, PFAS exist in anionic form. This means they carry a negative electric charge. Because of this, they’re called anions. We can note this by writing “PFAS⁻”.
Because opposite charges attract, PFAS⁻ will adhere to positively charged plastic beads (resins) inside a filtration column while displacing (exchanging) the chloride anions already on the column.
Newly formed ionic pairs, each consisting of one negative and one positive ion, become stuck, allowing PFAS-free water to pass out of the column.
AER filters tend to be more expensive than GAC.
Unlike GAC, however, most ion exchange resins are single use. This means they cannot be regenerated and reused. It is possible to regenerate them to their initial condition using a saturated salt solution (brine).
However, this is rarely the case when specialty AER columns are used to remove PFAS. Instead, resins are usually incinerated, potentially releasing PFAS and their burned byproducts into the air.
3. Reverse Osmosis Filters & Nanofiltration
Both reverse osmosis (RO) and nanofiltration (NF) methods involve a delicate membrane under high pressure. This means these methods require high energy input, unlike the other methods.
Because RO membranes will be damaged by chloride (which is usually present in treated water), you may find a GAC pre-filter installed before incoming water hits the RO membrane. The pre-filter traps the chloride.
Under most conditions, RO and NF are as effective at removing PFAS as the other methods described here. However, there is an important difference.
Both of these filtration methods produce a waste stream that contains the removed PFAS and will not be recuperated. This amounts to roughly five gallons of wastewater produced for every gallon of purified water (although that amount can vary depending on the specific filter).
So, these water filtration methods are not the best in water-scarce areas.
Worse, the contaminated water and membranes, like spent AER columns, may require a special hazardous waste handling permit. In 2022, the US EPA proposed classifying PFOA and PFOS as hazardous. If approved after the public comment period, such a permit will be necessary. For homeowners, this means RO, NF, and AER will be even more expensive.
What About Water Distillation for PFAS Removal?
In doing research for this timely and urgent topic of PFAS contamination in drinking water, I searched extensively for the water filtration methods proven effective to remove PFAS. In the section above, I featured the methods receiving US EPA approval.
Unfortunately, water distillation was not mentioned. Nor was it listed in the comprehensive reference list in the US EPA database although methods tried and failed (such as ozone) were described.
However, water distillation will remove >99% of all PFAS in water. The reason is simple: the boiling points of PFAS are well above the boiling point of water. This means only pure water will vaporize in the distilling chamber, then condense into liquid droplets.
The PFAS? They stay dissolved in the residual liquid water of the tank. (PSA: If you distill your water, you should never boil to dryness for safety reasons.)
For DIYers, you can distill water cheaply at home. For everyone else, I recommend a countertop or whole-home distillation setup. AquaNui offers USA-Made distillers that we’ve used successfully without incident for decades. (By popular demand, there is currently an 8-10-week lead time for delivery for their countertop model, so you may want to order one today! You can also use the code THEFILTERY5 for 5% off your distiller.)
There are a few potential downsides to distillation, which are worth considering. You may wish to remineralize the water (which is also the case for RO) if you don’t like the “flat” taste of distilled water.
Although it’s not true that drinking water “needs” minerals like sodium or calcium. You get minerals from the healthy foods you eat.
Additionally, the filtration process may be slow; some models take longer than others. A device with an automatic shutoff when the water level gets low solves this problem. Just let it run at night or while you’re at work. Plan ahead and make sure you have enough filtered water for what your household needs.
Pros and Cons of Water Filtration Methods That Remove PFAS
Here’s a summary of the pros and cons of the different types of water filters for PFAS removal.
|Granular Activated Carbon (GAC)
|– Less expensive
– Can be reused
– >99% effective at removing PFAS
|– Lots of variation; not all GAC filters remove PFAS
– Best carbon source is non-renewable coal
– Need to replace filters
|– Less expensive
– 95 to 99+% effective at removing PFAS
|– Needs to be combined with other filtration media in order to sufficiently remove PFAS
– Best carbon source is non-renewable coal
– Need to replace filters
|Anion Exchange Resin (AER)
|– >99% effective at removing PFAS
– Single use plastic beads (styrene)
– Results in sodium in the water; may not be suitable for people with high blood pressure
– Need to replace filter materials
|Reverse Osmosis/Nanofiltration (RO/NF)
|– >99% effective at removing PFAS
– Wastes water
– Single use plastic membranes
– Uses a lot of electricity
– May wish to remineralize
– Need to replace membranes
|– >99% effective at removing PFAS
– No filters to purchase
|– Expensive initially
– May wish to remineralize
|AquaNui (use code THEFILTERY5)
Final Thoughts on Water Filters That Remove PFAS
When considering all the advantages and disadvantages of the various filtration methods to remove PFAS from water, water distillation is your best bet.
Boiling water in a distiller involves converting water to vapor, leaving all other chemicals behind in the bottom of the boiling tank. As the vapor condenses, you get pure water, drop by drop.
Along with PFAS, water distillation will remove 99% of all chemical contaminants from water for the cost of electricity to boil the water. Plus, there are no filters to replace with either non-recyclable plastic beads or casing.
All other filtration methods have parts to replace frequently. There is no way to know definitively when filters are actually full of contaminants, so you will likely throw out partially unused filters.
In fact, to prevent the release of contaminants back into clean water, do not allow the filters to become full. (Use your best guess and follow the manufacturer’s recommendations.)
Because of so many harmful chemical contaminants including PFAS in water, filtration can make a big impact on your long term health. After careful consideration of all the options, water distillation is your best choice.
Do Brita filters remove PFAS chemicals?
Unfortunately, no. Some Brita filters remove some PFAS (with the Brita Elite removing ~78% in testing by the Environmental Working Group), but none of them remove the 99% that other filters do. Comparable pitcher-style filters that are better at removing PFAS include Clearly Filtered and Epic. Zero is a relatively good budget choice, which can get rid of ~95% of PFAS.
What is the best undersink filter to remove PFAS from drinking water?
Aquasana is one of the best brands for under-the-sink filters that can remove PFAS. They carry a reverse osmoses undersink filter that removes nearly all contaminants, as well as two different 3-stage underink filters that can also get rid of most PFAS. (However, the 3-stage ones cannot remove certain other contaminants such as radioactives, fluoride, arsenic, and cromium 6.) Under-the-sink water distillers are difficult to find.
Are PFAS in all tap water?
It’s unclear how widespread the PFAS truly are. A recent study from the US Geological Survey found PFAS in 45% of tap water in the U.S. Keep in mind, however, that they only tested 32 out of 12,000+ different PFAS, so it’s possible that PFAS are actually in more than 45% of tap water.
Will boiling water remove PFAS?
No, boiling water will not remove PFAS. The process of boiling water simply results in evaporation of some water, and it may even increase the concentration of PFAS compared to the volume of water as it evaporates.
What NSF standard is for PFAS?
If a water filter carries the NSF International 53 or 58 certification, it has undergone independent testing and has been validated to decrease PFOA or PFOS levels to below 70 parts per trillion (ppt). While this is a good thing to look for, keep in mind that an NSF 53 or 58 certified water filter does not mean it can get rid of 100% of PFAS, and that it’s only tested for 2 (out of 12K+) different PFAS.
What’s the best water filter for PFAS?
There isn’t a “best” water filters for PFAS “forever chemicals” because each type of water filter comes with pros and cons. That said, the types of water filters that can significantly reduce (up to 99%+) PFAS “forever chemicals” are certain activated carbon filters, ion exchange filters, reverse osmosis filters, and distillation.