You might be familiar with some perfluoroalkyl substances (PFAS for short) because of their presence in non-stick cookware (Teflon and other PFAS) , water/stain repellent finishes in carpets and furniture (Scotchguard etc) and in rain/ snow gear.  

Until just a couple of years ago, however,  no one (federal or state level)  really knew about their widespread presence in our drinking water.   No one was testing our water supply for this family of chemicals and so, while some water filtration companies did test for 1 or 2 of the most common PFAS chemicals, most  water filters were not focusing on PFAS chemical reduction.

Now, thanks to recent studies, we know that PFAS chemicals are more prevalent in the US water supply than previously thought…. we also know they are extremely harmful.  

Exposure to PFAS increases the risk of cancer, harms the development of the fetus and reduces the effectiveness of vaccines.  Mothers and young children may be most vulnerable to the chemicals, which can affect reproductive and developmental health.

Does your water contain PFAS?  

According to Environmental Working Group scientist, “EWG scientists now believe PFAS is likely detectable in all major water supplies in the U.S., almost certainly in all that use surface water.”   PFAS has even been detected in rain water.  The blood of nearly all Americans are contaminated with PFAS 

Part of the problem is that PFAS  in water are not regulated at the  federal level (the EPA has recently set a ‘health advisory’     for two PFAS chemicals - PFOA and PFOS-  but there are many more - upwards of 600-  that are just as harmful and commonly used - and these limits are not as low as some scientists would recommend) .  Some states are taking matters into their own hands and setting their own limits for some of these chemicals (these states include:  California, Connecticut, Massachusetts, Michigan, Minnesota, New Hampshire, New York, North Carolina and Vermont.)

Regardless of state regulations, when EWG looked at water supply sources around the country, only 3 cities of the ones they looked at (Meridian, Mississippi, Seattle and Tuscaloosa, Alabama) had no PFAS contamination. 

 These were the cities they found had the highest levels of PFAS in the public water supply:

Brunswick County, NC

Quad Cities Iowa

Miami, FL

Bergen County, Nj

Wilmington NC

Philadelphia, PA

Louiseville, KY

New Orleans, LA

Charleston, SC

Decatur Alabama

Washington DC

Prince Georges county, Md

Rockingham County, NH

Colombus Ohio

Ann Arbor Michicgan

Atlanta GA

Indianapolis Ind

Minneapolis, Minn

Chicago ILL

Unfortunately, regardless of where you live, it is safe to say there is a high probability that you are being expose to PFAS in your drinking water. This means it is important to filter your tap water before drinking it…

The next obvious question is:  what water filtration system will remove these chemicals from my water?

Enter Heather Stapleton and her team from Duke University’s and North Carolina State University’s latest study “Assessing the Effectiveness of Point-of-Use Residential Drinking Water Filters for Perfluoroalkyl Substances (PFASs)”  

They looked at all types of water filters ( the filter on your refrigerator door, the pitcher-style filter you keep inside the fridge under sink filtration systems and whole-house filtration system  from all different price points and found: 

1. while using any filter is better than using none – many of these filters are not adequately filtering out PFAS chemicals.

2. many household filters are only partially effective at removing toxic perfluoroalkyl substances, from drinking water.

3. A few, if not properly maintained, can even make the situation worse.

Conclusions of the Study:

1. Under sink two stage filters filtration systems: achieved near-complete removal of the PFAS chemicals

2. Under sink reverse osmosis: achieved near-complete removal of the PFAS chemicals

3. Activated-carbon filters (used in many pitcher, countertop, refrigerator and faucet-mounted styles):   removal levels were inconsistent and unpredictable. In some cases, the chemicals were completely removed; in other cases they were not reduced at all.

4. Whole-house systems:  removal levels also  varied widely and in some cases actually increased PFAS levels in the water.”

These are the under sink reverse osmosis filters that were tested (I have added some of these to my Amazon Shop if you are interested , under ‘water filters/)

Aquasana: Under Sink OptimH2O® Reverse Osmosis + Claryum®

Culligan Reverse Osmosis

Eco Water Reverse Osmosis

Apec Water: RO-45 zero water

AQUA TRU Countertop Water Filtration

Primo Reverse Osmosis

Kinetico K-5 

Puronics Micromax 7000

Culligan Aqua-Cleer RO30

Puronics Micromax 7000

APEC RO-45

These are the dual stage filters

Kenmore Dual-Stage

GE: FXSVC

Aquasana AQ-5200

Hydroviv Tailored Tapwater & HDX Whirlpool 3

Other filters that preformed well 

Hydroviv Tailored Tapwater (undersink single stage)

eSpring 100189 (UV lamp off) (undersink single stage) 

I have gotten asked a lot over the years about Berkey- they have always shown to be a great filtration system alternative- especially for those who don’t have the space for an under sink system, who are renting or don’t have the budget for a reverse osmosis system….. however in this study  the one Big Berkey that was looked at preformed pretty bad for PFAS.  Three other Berkey ‘pitcher’ filters did much better.   I have reached out to Berkey to see what their response is….and am trying to determine with the researchers which models preformed better…but for now am pausing on recommending them (mind you my mother and sister have these systems….) 

The full list of filters that were tested can be found here

Please note:  this test only look at PFAS chemicals and not how well these filters filtered out other known contaminants in water.   Before purchasing a water filtration system you should definitely compare systems with what is actually in your tap water.

My thoughts

Reverse osmosis systems are superior in eliminating all toxins- however they do have some drawbacks to consider:

1. waste a lot of water

2. they require a bit more space to install

3. are not idea for renters (although the Aquatru is a reverse osmosis counter filter which is actually perfect for renters but does come at a higher price tag. and also stores water in plastic)

4. oYou must re- mineralize filtered water because by eliminating everything they also eliminate beneficial minerals from drinking water.

I currently have a 4 stage Pure Effects Filter which I still feel good about- even though it was not tested here (but if 2 stage filters did well I would suspect 3 and 4 to do well too) . At the time when I bought this I took a lot of things into account and one of them was that I simply did not have under counter space for a reverse osmosis under counter system… I would have probably considered one had I had the space.