Laboratory tests of Black Berkey filters
Independent Black Berkey® tests
What the Black Berkey reports demonstrate.
A clear reading of the published tests on micro-organisms, heavy metals, PFAS, and chemical and radiological contaminants, with the limitations of each result.
Key results
Four performance figures to remember.
These figures come from reports carried out on Black Berkey samples under specific laboratory conditions. The volumes shown are those actually covered by each test.
Microbiological reduction threshold of 6 log reached or exceeded in the published test.
Published reduction for the coliphages used as test organisms.
Result maintained up to the 25-gallon endpoint, i.e. approximately 94.6 litres.
Reduction maintained up to the 200-gallon endpoint, i.e. approximately 757 litres.
Level of evidence
Laboratory reports, not an active certification.
This distinction makes it possible to present Black Berkey performance without turning an independent test into an official certification.
Many contaminant families documented
The available reports cover, among others, micro-organisms, metals, pesticides, pharmaceuticals, petroleum products, PFAS and radiological contaminants.
A test method is not a product certification
Some reports cite NSF/ANSI 42 or 53 protocols. However, the current NSF listings consulted for Berkey do not confirm an active certification of the Black Berkey itself.
A laboratory result describes the sample and the conditions of the report. A certification involves a separate official listing and monitoring.
Detailed results
Compare the values actually published.
The ‘>’ and ‘<’ signs reflect the measurement limits of the reports. The table presents a representative selection, not an extrapolation to all contaminants.
| Parameter | Input | Output or endpoint | Reduction |
|---|---|---|---|
| Pathogenic bacteria, published threshold | Microbiological test | ≥ 6 log reduction | ≥ 99.9999 % |
| Viruses tested, published threshold | Coliphages | > 5 log reduction | > 99.999 % |
| Cryptosporidium and Giardia | 7.7 × 10² (oo)cysts/mL | < 2.0 × 10⁻² | > 99.997 % |
| Lead, 200 gal endpoint | 1,010 µg/L | 8.7 µg/L | 99.1 % |
| Arsenic | 312 µg/L | < 2 µg/L | > 99.9 % |
| Chromium | 310 µg/L | < 2 µg/L | > 99.9 % |
| Cadmium | 30.5 µg/L | < 0.5 µg/L | > 99.7 % |
| Mercury | 6.1 µg/L | < 0.5 µg/L | > 99.9 % |
| Chloramines | 3.2 mg/L | < 0.1 mg/L | > 99.9 % |
| Free chlorine | 2.1 mg/L | < 0.1 mg/L | > 99.9 % |
| Pesticides tested | Varies by compound | < 0.5 µg/L | > 99.9 % |
| Pharmaceuticals tested | Approx. 20 µg/L | < 0.1 µg/L | > 99.9 % |
| Petroleum products tested | Approx. 50 µg/L | < 0.5 µg/L | > 99.9 % |
| PFOA, 25 gal endpoint | 1.00 µg/L | < 0.002 µg/L | > 99.9 % |
| Gross alpha activity, 50 gal endpoint | 100.5 pCi/L | 1.31 pCi/L | 98.7 % |
| Gross beta activity, 50 gal endpoint | 100.1 pCi/L | 4.7 pCi/L | 95.3 % |
| Uranium, 50 gal endpoint | 49.1 µg/L | 1.45 µg/L | 97.0 % |
The results apply to the samples and conditions described in the reports. Rows covering a family summarise several compounds tested individually in the source document.
Scope of testing
Broad coverage, organised by family.
Open a category to see the main contaminants mentioned in the published documents.
Micro-organisms and parasites
MS2 and Fr coliphages, Raoultella terrigena, Salmonella enterica, E. coli, Cryptosporidium parvum, Giardia lamblia and Leptospira.
Heavy metals
Aluminium, antimony, arsenic, beryllium, bismuth, cadmium, chromium, copper, iron, lead, manganese, mercury, nickel, selenium and zinc.
Pesticides, VOCs and by-products
DDT, atrazine, chlordane, lindane, PCBs, semi-volatile organic compounds, trihalomethanes, HAA5 and chloroform, among other substances listed.
Pharmaceuticals and endocrine disruptors
Acetaminophen, caffeine, carbamazepine, ciprofloxacin, erythromycin, sulfamethoxazole, trimethoprim, BPA, diclofenac, ibuprofen, naproxen and triclosan.
PFAS and perfluorinated compounds
PFOA was the subject of the direct endurance test. The report also presents PFBS, PFDA, PFHxA, PFNA, PFOS and PFHxS as surrogate results based on PFOA.
Radiological and uranium
Separate tests on gross alpha activity, gross beta activity and uranium, with successive measurements up to 50 gallons.
Lifespan and volumes tested
How far has performance been verified?
The stated capacity is approximately 11,350 litres per element, i.e. 22,710 litres for a pair. This does not mean that every contaminant has been tested up to this volume.
PFOA actually measured
The last point in the PFOA report is at 25 gallons, with a reduction greater than 99.9 %.
Radiological and uranium
The alpha, beta and uranium reports publish their last results at 50 gallons.
Lead actually measured
The dedicated lead test reaches 200 gallons, with a final reduction of 99.1 %.
Stated capacity per element
This figure serves as a guide for replacement. It is not an identical endurance test for each contaminant.
The stated service life and the volume covered by a report answer two different questions. The first concerns replacement, the second the exact scope of the published evidence.
Source documents
The reports, clearly identified.
The main documents are linked directly. Historical links kept on Berkey Swiss are flagged as such.
Metals, pesticides, pharmaceuticals, chlorine and petroleum products
Main report with input and output concentrations and reduction rates.
Cryptosporidium and Giardia
Filtration efficacy test on two Black Berkey units.
Viruses and bacteria
Historical report used for the log reductions on the test organisms.
PFOA and perfluorinated compounds
Direct PFOA test up to 25 gallons and table of surrogate compounds.
Lead up to 200 gallons
Twenty successive measurement points, with results up to approximately 757 litres.
Alpha, beta and uranium
Three separate reports with measurement points up to 50 gallons.
VOCs, pesticides, THMs, HAA5 and chloroform
Organic analyses carried out by the Environmental Toxicology Laboratory.
Metals, MBAS, chlorine, turbidity and chromium VI
Supplementary document covering parameters not detailed in the main table.
Leptospira, microcystin-LR and Microcystis algae
Two supplementary historical documents kept on Berkey Swiss.
Official test page and NSF listings
Two access points for checking the published documents and the currently active listings.
Frequently asked questions
Understanding the Black Berkey results.
Is the Black Berkey NSF certified?
The Black Berkey reports cite protocols and criteria associated with the NSF/ANSI 42, 53 or NSF P248 standards. This does not amount to a confirmed active certification of the Black Berkey in the current NSF listings. The listings should always be checked separately.
Why do the reports sometimes use ‘> 99.9 %’?
Because the output concentration is below the laboratory’s limit of detection or quantification. The ‘>’ sign indicates a minimum demonstrated reduction, not an absolutely zero concentration.
Are the results proven up to 22,710 litres?
No. The 22,710 litres correspond to the stated capacity for a pair of elements. Each report has its own volumes, for example 25 gallons for PFOA, 50 gallons for the radiological tests and 200 gallons for lead.
Were all the PFAS in the report tested separately?
No. PFOA was measured directly up to 25 gallons. The document presents several other perfluorinated compounds as surrogate results based on PFOA, used as a representative compound.
Does the Black Berkey reduce fluoride?
One main report publishes an initial fluoride reduction of more than 99.9 %. This one-off result does not demonstrate sustained capacity over the full lifespan. PF-2 elements are the complementary product dedicated to fluoride reduction, with their own stated capacity.
Are these tests sufficient for any non-potable water?
The reports describe controlled tests on certain organisms and contaminants. They do not replace an analysis of the water source or the guidance of the authorities. In the event of known or suspected microbiological contamination, local health instructions must be followed.
New generation Berkey®
Discover the Phoenix Gravity filters.
Phoenix Gravity New Millennium Edition™ elements are the filters currently offered for compatible Berkey systems.
View the Phoenix filters