Does Berkey Reduce Arsenic? Lab Results for Black Berkey and Phoenix

Yes, Berkey gravity systems reduce arsenic. Independent laboratory testing recorded Black Berkey elements reducing arsenic by 99.0% or more at a 200 microgram per liter challenge (LA County Environmental Toxicology Laboratory, EPA Method 200.8). Berkey Phoenix elements, the current in-stock replacement, reduced arsenic by 99.5% or more at the same challenge level, with filtered water below the lab's 1 microgram per liter detection limit (CVR Labs, NABL accredited). For households on well water or where arsenic concentrations are known to be high, adding a PF-2 activated alumina post-filter provides additional targeted arsenic reduction beyond the primary gravity element.

How Berkey Reduces Arsenic

Arsenic enters drinking water primarily through natural geological leaching from rocks and soils into groundwater. It is tasteless, colorless, and odorless, which makes testing the only reliable way to know it is present. The EPA's maximum contaminant level for arsenic in public drinking water is 10 micrograms per liter (parts per billion), with a stated long-term goal of zero. For background on arsenic exposure, health effects, and where it appears in US water supplies, see our guide on arsenic in drinking water.

Berkey gravity systems address arsenic through two complementary stages:

1. The primary gravity element (Black Berkey or Phoenix) reduces arsenic alongside a wide range of heavy metals, VOCs, pesticides, pharmaceuticals, and other contaminants. This is the workhorse stage that handles arsenic for most households.
2. The optional PF-2 post-filter adds a targeted activated alumina stage designed specifically for arsenic and fluoride. PF-2 threads onto the primary element and sits in the lower chamber. It is recommended when arsenic is known to be elevated or when source water is well water rather than municipal supply.

Black Berkey Arsenic Test Results

Black Berkey elements were tested against arsenic by the County of Los Angeles Environmental Toxicology Laboratory, a state-accredited environmental testing facility. The test challenged the element with arsenic at 200 micrograms per liter, which is 20 times the EPA action level of 10 micrograms per liter.

What the 99.0% figure actually represents. The lab's reporting limit for arsenic was 2.0 micrograms per liter. Post-filtration arsenic came back below that reporting limit, which means the math caps at 99.0% from a 200 microgram per liter challenge. The filtered water sat well below the 10 microgram per liter EPA limit throughout the test. To support a higher percentage claim would require a lab capable of measuring arsenic below 0.2 micrograms per liter, which is below routine laboratory practice for arsenic.

Berkey Phoenix Arsenic Test Results

Berkey Phoenix elements were tested separately by CVR Labs, an independent NABL-accredited laboratory in India. The Phoenix test used the same 200 microgram per liter arsenic challenge as the Black Berkey test, allowing a meaningful comparison.

Important framing. The difference between Black Berkey's 99.0% and Phoenix's 99.5% is not a performance gap between the two elements. Both filters reduced arsenic to below their respective labs' minimum detection limits at the same stress challenge. The two labs simply had different detection limit precision (2.0 µg/L versus 1.0 µg/L), which is what determines the maximum provable percentage in each report. Both filtered water samples sat well below the 10 microgram per liter EPA limit. Both reports support gravity filtration as an effective arsenic reduction method at residential exposure levels.

For complete lab documentation, see the Black Berkey inorganic test results and the Berkey Phoenix VOC, pesticide, and heavy metals test results.

When to Add the PF-2 Post-Filter

The primary gravity element handles arsenic at typical residential concentrations. The PF-2 is a targeted second stage using activated alumina media, designed specifically for arsenic and fluoride. It does not replace the primary element; it threads onto it and sits in the lower chamber, providing additional reduction at the same point-of-use.

Two considerations matter when deciding whether to add PF-2:

Arsenic Concentration in Your Source Water

If your water has been tested and arsenic sits at or below the EPA action level of 10 micrograms per liter, the primary gravity element alone reduces arsenic well below detectable levels. If arsenic is confirmed above the EPA limit, particularly if it is sharply above (well water in arsenic-hotspot regions sometimes runs 50 to 100 micrograms per liter or higher), the PF-2 provides extra reduction headroom.

Form of Arsenic Present

Arsenic in water exists in two forms. Arsenic V (arsenate) is more common in chlorinated municipal supply and is more readily addressed by adsorption media. Arsenic III (arsenite) is more common in anaerobic well water and is harder to reduce unless first oxidized to arsenic V. The PF-2's activated alumina is most effective against arsenic V and pre-oxidized arsenic III. For well water with high arsenic III, having both the primary gravity element and the PF-2 provides redundant reduction stages, which is why the PF-2 is a particularly strong addition for well water households.

For current PF-2 specifications, lifespan, and pricing, see the PF-2 product page.

Should You Add the PF-2 to Your Berkey?

How Berkey Compares to Other Arsenic Reduction Options

This page is the brand-specific answer: yes, Berkey reduces arsenic, here is the data, here is how to configure your system. For a side-by-side comparison of Berkey against reverse osmosis, faucet-mount filters, pitchers, distillation, and whole-house systems, with a 5-year cost analysis and use-case recommendations, see the arsenic water filter buying guide. For broader heavy-metal context, see the heavy metals water filter guide and the full contaminant list a Berkey reduces.

Frequently Asked Questions

Does Berkey reduce arsenic?

Yes. Black Berkey elements reduced arsenic by 99.0% or more in independent lab testing at a 200 microgram per liter challenge (LA County Environmental Toxicology Laboratory, EPA Method 200.8, August 2012). Berkey Phoenix elements, the current in-stock replacement, reduced arsenic by 99.5% or more at the same challenge level, with filtered water below the lab's 1 microgram per liter detection limit (CVR Labs, NABL accredited, March 2025). Both elements reduce arsenic well below the EPA action level of 10 micrograms per liter.

Do I need PF-2 filters if I already have Black Berkey or Phoenix?

Not for typical municipal water. The primary gravity element alone reduces arsenic by 99% or more, which is sufficient for residential supplies at or near the EPA action level. PF-2 is recommended when source water is well water, when arsenic is confirmed sharply above the EPA limit, or when the household includes pregnant women, infants, or young children for whom additional reduction headroom is valuable. For municipal water with no known arsenic issue, the primary element on its own is sufficient.

How does Black Berkey reduce arsenic?

Black Berkey elements use a proprietary blend of multiple media types, addressing contaminants through four mechanisms: microfiltration through tortuous-path pores, adsorption to activated carbon, absorption, and ion exchange. The combined media addresses arsenic alongside a wide range of other heavy metals, VOCs, pesticides, and pharmaceuticals. Independent lab data confirms the result at 99.0% or more reduction at a stress challenge 20 times the EPA limit. For the full list of contaminants addressed by each filter element, see the Black Berkey complete contaminant list and the Phoenix complete contaminant list.

How does the PF-2 add to arsenic protection?

The PF-2 is an activated alumina post-filter designed specifically for arsenic and fluoride. It threads onto the bottom of the primary gravity element and sits in the lower chamber, providing a targeted second stage at the same point-of-use. The PF-2's activated alumina is most effective against arsenic V and pre-oxidized arsenic III. For well water with elevated arsenic III, the combination of the primary gravity element plus the PF-2 provides redundant reduction stages.

Are Black Berkey filters still available?

Standalone Black Berkey replacement elements are currently sold out following an EPA regulatory matter that halted production. New Berkey systems still ship with Black Berkey elements included as standard, drawn from pre-stop-sale inventory. For replacements, the in-stock option is the Berkey Phoenix New Millennium Edition, made by the same manufacturer, New Millennium Concepts, and a direct drop-in for any existing Berkey system. Black Berkey elements sold on Amazon, eBay, or Walmart are likely counterfeit.

How long do Berkey filters last when reducing arsenic?

Both Black Berkey and Phoenix elements are rated for 6,000 gallons per pair under normal use, which translates to several years for a typical household. Very high arsenic concentrations or heavy heavy-metal load may reduce that capacity, so replace elements on schedule and consider testing your water periodically. PF-2 lifespan is shorter (typically 1,000 gallons per set of two or one year, whichever comes first). See the PF-2 product page for current specifications.

Can I test my own water for arsenic before buying?

Yes, and it is recommended for well water. Send a sample to a certified laboratory for the most reliable result, including the specific arsenic concentration in your water. Some at-home test kits indicate presence or absence but do not quantify exact levels. For municipal water, your utility's annual Consumer Confidence Report includes arsenic among the reported contaminants. Testing first allows you to match the right filter configuration to your actual water. If your water testing also shows other heavy metals, see our guides on lead reduction and chromium-6 reduction.