What Do Berkeys Filter Out?

If you’ve looked into purchasing an at-home water treatment device, you’ve likely come across Berkey filters. With claims about being “the global standard in water filters” and typical prices from $400 to $500, Berkey filtration units command attention. [1]

In this inside look, we dig into the science behind the Berkey filter and the manufacturer’s claims in order to better understand if Berkeys are right for your water treatment needs.

What Are Berkey Filters Made Of?

Any filter product has two distinct components: the filter housing and the filter element. Berkey filter systems are composed of the tall, metal (or plastic, in the case of the Berkey Light) housing, and the filter elements inside, the components that do the actual water treatment. In the various Berkey filter products, these elements are called the Black Berkey Elements. In order to understand how Berkey filters work, we need to know what the Black Berkey Elements are made of. 

New Millenium Concepts, the manufacturer of Berkey filters, is a bit vague on the subject. According to their website, the “Black Berkey® Elements are made from a proprietary blend of media, and are backed by independent third-party testing.” [2]

What do Berkey dealers say Black Berkey Elements are made of?

Some of the larger authorized dealers get more specific, but not by much. One dealer explains that the filter elements are composed of over “six different media types” that collectively employ microfiltration, ion exchange and adsorption. [3] Another specifies that the mixture of filtration media includes “high-grade coconut shell carbon”. [4]

Does anyone have a best guess?

Since we don’t have more detailed information about the materials in the Black Berkey Elements, we can only make an educated guess.

Activated carbon and ion exchange resin are common materials for at-home, gravity fed water filters and are likely culprits for the Black Berkey Elements. More specifically, the filters appear to be made of carbon block, a specific type of activated carbon where the carbon is powdered and pressed into a solid. Carbon block and ion exchange also align with the descriptions of the filter elements by dealers.

What Contaminants Do Berkey Filters Reduce?

New Millenium Concepts claims the Black Berkey Elements reduce over 200 contaminants in drinking water. They also adamantly point out they’ve conducted independent testing at third-party laboratories. But how sure can we be that these claims are legitimate?

Are Berkey filters certified?

Typically, we would look to a water treatment product’s certifications to determine if their reduction claims have merit (as we did in these investigations of Brita and PUR filters).

Certifications for drinking water treatment products ensure that the product meets strict standards regarding:

• Contaminant removal
• Structural stability
• Materials safety
• Factory audit
• Provision of accurate and sufficient literature

Looking for more info on certifications? Read our deep dive.

Berkey filters, and specifically the Black Berkey Elements, are not certified for the reduction of any contaminants. 

The manufacturer’s website specifically states that the Black Berkey Elements exceed the requirements for meeting the NSF/ANSI 53 standard, but they have never been certified to do so by any accredited certifying body (e.g. NSF, WQA, or IAPMO). [5]

Individual NSF/ANSI standards typically encompass many contaminants, with certifications given on a contaminant by contaminant basis. A product may meet NSF/ANSI 53 standard for lead reduction but not for chromium reduction—even though NSF/ANSI 53 includes both contaminants. The claim that a standard is exceeded without specifying contaminants is not particularly useful.

But what about all of those lab results posted on the Berkey website?

Despite not having any certifications, New Millenium Concepts has paid third-party laboratories to conduct a fair amount of testing of the Black Berkey Elements and these results can be found on their website. [6] While this gives the appearance of legitimacy, these lab results contain many glaring issues.

First, while these may all be accredited laboratories, none of them are accredited certifying agencies (e.g., NSF, WQA, IAPMO). In Berkey’s case, the laboratory procedures that were conducted were not nearly as thorough as those used in product certification. Any claims of meeting NSF/ANSI standards are patently untrue. 

One key difference in these laboratory tests versus those required for certification is the length of the filter tests. Certifying agencies conduct testing on at-home water treatment products through the full lifetime of the filters—and beyond—to see how they perform as they are “used up.” In fact, for filters like those found in Berkeys, certifying agencies run tests out to two times the rated life of the filter. New Millenium Concepts claims that Black Berkey Elements have a filter life of 3000 gallons—lab tests would need to run up to 6000 gallons to provide evidence of effective contaminant reduction to meet NSF/ANSI standards. 

Out of all the lab reports posted that even specify test length, the longest test was run out to 200 gallons. That’s only 3% of the required volume for a certification for contaminant reduction! Most of the lab tests were done with far less volume, providing even less evidence of effectiveness.

Meanwhile, a few of the lab reports posted are either incomplete or give no description of procedure whatsoever. This lack of information about lab procedures is concerning. Regardless of the thoroughness of the lab reports, we don’t have information regarding materials safety, structural stability, accuracy of the product literature or any type of factory audit for the Berkey in general. All of this information is important and would have been provided had the filters been certified. 

All in all, we can’t put much stock in Berkey’s third-party lab results. Actually acquiring certification to NSF/ANSI standards goes a long way toward building consumer confidence, something the water treatment product industry often lacks. It would be great if there were other alternatives to certification since it is quite expensive and involved, but with the obvious inconsistencies in manufacturer claims, certification is our best option right now.

What should Berkey filters reduce based on the material in the filter?

Without reliable lab results, we wanted to take a little time at the end here to explore whether or not the Berkey’s reduction claims are consistent with the science behind the filters.

Since we don’t have confirmation regarding what the filters are made of, we’ll try to assess what would be reduced if the filter media were composed of carbon block and ion exchange resin.

Carbon Block

Carbon block is a type of activated carbon that is powdered and pressed into a block. Activated carbon works by adsorbing, or binding, contaminants to its surface as the water passes through. Since the carbon particles in carbon blocks have very high surface area and small pores, they are good at pulling out many different contaminants. Carbon blocks are effective at reducing:

• Organic contaminants, like pesticides, pharmaceuticals and PFAS compounds
• Certain heavy metals
• Some larger pathogens like Cryptosporidium and Giardia

Ion Exchange

Ion exchange resins work a bit differently than activated carbon. Ion exchange resins are composed of little charged beads that have harmless molecules (like sodium) stuck all over them and, as water passes by these beads, the target contaminants get stuck to the resin beads as they are exchanged for harmless molecules that are released into the water in their place. The specific resins are chosen based on the contaminants you want to remove from your water. Some common compounds ion exchange resins remove include: certain heavy metals, hardness minerals, nitrate, arsenic, uranium, fluoride, and other dissolved ions.

What Contaminants Do Berkey Filters NOT Reduce?

Since we can’t be positive of what Berkey filters do reduce, we can’t make an exhaustive list of what they don’t reduce. However, here we are trusting the information that New Millenium Concepts posts regarding contaminants that Berkey filter elements do not reduce since they have no incentive to misrepresent the limitations of the filters. 

Berkey systems require an additional filter element to reduce arsenic and fluoride, though those are not certified and we cannot vouch for their effectiveness. Either way, the Black Berkey Elements are unlikely to remove these two elements.

The Berkey website makes it clear that Berkeys do not reduce the following contaminants:

1. nitrate, or
2. hardness minerals

Ion exchange is a common treatment technology for the reduction of nitrate and hardness minerals but not all ion exchange resins remove these. Black Berkey Elements likely include an ion exchange resin that targets other contaminants and does not reduce nitrate and hardness minerals.

Performance testing is the best way to understand what contaminants your Berkey can and cannot reduce in your specific water source.

How do you performance test your Berkey?

Is a Berkey Filter Right For Me?

All in all, the materials that we believe comprise the Black Berkey Elements could potentially reduce many of the contaminants they claim to, but we don’t have confidence in the full list for the entire lifetime of the filter. They claim to reduce far more contaminants than similar products that are fully certified, like Brita and PUR pitcher filters.

Without extensive testing or certification to NSF/ANSI standards for all of their claims, we can’t confirm that Berkey filters reduce all of the contaminants they claim to reduce.

In general, we can’t recommend purchasing filters that aren’t certified for reduction of the contaminants that they claim. Berkey is not certified, it’s priced fairly high, and it doesn’t seem to offer any of the benefits that other similar, certified filters offer. 

We cannot recommend Berkey filters until proper performance certification is pursued.