Trust is measurable.
Tested in independent laboratories, not based on manufacturer's self-declaration.
At BACHGOLD, we are passionately committed to developing high-quality products that provide access to clean water. We are aware that our customers' trust is always measured by the quality of our products.
For this reason, we ensure that the performance of our water filters is verified under standardized conditions through extensive testing in independent laboratories: for the protection of our customers and as part of our corporate responsibility.
Independently verified according to recognized standards
Tested by an independent laboratory
Our water filters are tested by IAPMO (International Association of Plumbing and Mechanical Officials). IAPMO is an internationally active testing and certification organization with many years of experience in testing products and technologies in the field of water quality and drinking water treatment.
The filter performance is examined under controlled laboratory conditions using standardized and internationally recognized test procedures. This ensures that the performance of our water filters is verified independently and under reproducible conditions.
Tested in accordance with the requirements of the NSF P231 test protocol
Our water filters are tested according to the specifications of the NSF P231 test protocol. The NSF (National Sanitation Foundation) is an internationally recognized organization that develops standards and testing procedures for products in the areas of drinking water and water treatment, among others.
The NSF P231 test protocol was specifically developed to evaluate water treatment systems designed to reduce microbiological contaminants. It defines demanding and standardized test conditions: the composition of the test water, the volume of water to be tested, and a multi-day test procedure across various operational phases.
This allows the filter performance to be verified and objectively evaluated under reproducible conditions.
What do the tests show?
Filter effectiveness over multiple operating phases
Testing in accordance with the NSF P231 protocol requirements evaluates filter performance across various operational phases. This ensures that the required reduction efficiency is maintained not only at the beginning, but throughout the entire specified filter capacity.
Degree of reduction as a log value
The test results show how effectively the concentration of the tested microorganisms is reduced by the filter. This reduction performance is standardized and expressed as a so-called log reduction.
What does "log" mean?
In simple terms, the log value describes how significantly the number of microorganisms is reduced. For example, a log-4 reduction means that 99.99% of the microorganisms are removed. Simply put:
- 10,000 microorganisms
- 1 remains mathematically
- 100,000 microorganisms
- 10 remain mathematically
- 1,000,000 microorganisms
- 100 remain mathematically.
The higher the log reduction, the greater the filter's reduction performance. The specific results and log values achieved vary depending on the filter model and the microorganism tested and are therefore reported separately for each individual water filter.
Defined requirements instead of a snapshot
The test protocol specifies concrete requirements for test water, test procedure, load, and filter quantity. This creates standardized and reproducible conditions under which the performance of the filter systems can be objectively evaluated.
Why micron specifications are only of limited significance.
Measurable filter performance instead of manufacturer specifications.
The pore sizes of hollow fiber membrane filters are often merely manufacturer specifications and are rarely verified independently. Hardly any reputable standards institute evaluates water filters based solely on pore size, as filtration performance depends on both the material properties and the manufacturing quality.
The log reduction allows for a more meaningful assessment, as it quantifies the actual measured reduction performance of the filter. Through standardized test procedures, this enables the filtration performance to be evaluated objectively and comparably.
Self-press
Tested filter capacity of over 1,500 liters
The microbiological filtration performance of the BACHGOLD Selfpress was laboratory tested over the entire stated filter capacity of 1,500 liters.
The filter performance was not only tested at the beginning, but also throughout several defined operating phases. In addition, the testing included 48-hour stagnation periods to verify filter performance even after extended breaks in use.
The results are reported as a log reduction as well as the corresponding percentage reduction.
- 1,500 L Verified filter capacity
- 8 Measurement points
- 2 × 48 h Stagnation phases
- 3 Filter elements tested in parallel
- Log 8 Measured filter performance
E. coli: reduction over the full filter capacity
For the testing of bacterial reduction performance, Escherichia coli (E. coli) was used as the test organism. E. coli is frequently used in the microbiological examination of water as an indicator organism for fecal contamination and is therefore suitable for the standardized assessment of the bacterial reduction performance of a water filter.
| No. | Measuring point (capacity 1,500 L) | Inflow (CFU/ml) | Effluent (CFU/100 ml) | Reduction (%) | Log reduction value | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Filter 1 | Filter 2 | Filter 3 | Filter 1 | Filter 2 | Filter 3 | Filter 1 (log value) | Filter 2 (log value) | Filter 3 (log value) | |||
| 1 | Start | 6 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99,999,999 | 99.999999 | 8.77 | 8.77 | 8.77 |
| 2 | 25% (375 L) | 5 × 10⁸ | none detectable | none detectable | none detectable | 99,999,999 | 99.999999 | 99.999999 | 8.69 | 8.69 | 8.69 |
| 3 | 50% (750 L) | 5 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99.999999 | 99,999,999 | 8 | 8.69 | 8.69 |
| 4 | After 48 h of stagnation | 5 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99.999999 | 99,999,999 | 8.69 | 8.69 | 8.69 |
| 5 | 60% (900 L) | 6 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99,999,999 | 99,999,999 | 8.69 | 8.69 | 8.69 |
| 6 | 75% (1.125 L) | 5 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99,999,999 | 99,999,999 | 8.69 | 8.69 | 8.69 |
| 7 | After 48 hours of stagnation | 5 × 10⁸ | none detectable | none detectable | none detectable | 99.999999 | 99,999,999 | 99.999999 | 8.69 | 8.69 | 8.69 |
| 8 | 100% (1,500 L) | 5 × 10⁸ | none detectable | none detectable | none detectable | 99,999,999 | 99.999999 | 99,999,999 | 8.69 | 8.69 | 8.69 |
Test water composition
The Selfpress was tested using various defined test water compositions in accordance with the specifications of the NSF P231 test protocol. In addition to general test water, a more demanding challenge test water was also used to verify filter performance under more difficult conditions.
| Feature | General test water: specification | General test water: in the laboratory | Challenge test water: Specification | Challenge test water: in the laboratory |
|---|---|---|---|---|
| Chlorine (mg/l) | chlorine-free | < 0.05 | chlorine-free | < 0.05 |
| pH value | 6.5 to 8.5 | 6.90 to 7.50 | 9.0 ± 0.2 | 9.0 to 9.2 |
| TOC (mg/L) | 0.1 to 5 | 0.1 to 0.2 | at least 10 | 10.0 to 11.0 |
| Turbidity (NTU) | 0.1 to 5 | 0.1 to 0.3 | at least 30 | 30 to 32 |
| Temperature (°C) | 20 ± 5 | 23 to 24 | 4 ± 1 | 8 to 10 |
| TDS (mg/l) | 50 to 500 | 250 to 300 | 1,500 ± 150 | 1,500 to 1,580 |
Classification of test results
The BACHGOLD Selfpress achieved at least Log 8 over the entire tested filter capacity of 1,500 liters, which corresponds to a reduction of 99.999999% of E. coli bacteria. Even after 48 hours of stagnation, the filter performance remained intact.
Log 8 means: The concentration of bacteria is mathematically reduced by a factor of 100 million. This corresponds to a reduction of 99.999999%.
Squeeze
Tested filter performance over 500 liters
The microbiological filtration performance of the BACHGOLD Squeeze was tested over the entire specified filter capacity of 500 liters. Three different test organisms or test particles were used to assess the reduction performance against bacteria and viruses, as well as particle reduction in the size range relevant for testing using standardized test particles.
Measurements were taken at regular intervals of 10% of the filter capacity each. This allowed the filter performance to be verified from the beginning of use until the maximum capacity was reached.
- 500 L Tested filter capacity
- 11 Measurement points
- every 10% measured by capacity
- 3 Test organisms and test particles
- Log 7 Bacteria
- Log 4 Viruses
- Log 3 Protozoa
Bacteria, viruses, and protozoan surrogates
Eleven measurement points were recorded for each test organism – from the start of the test to full filter capacity.
Klebsiella terrigena · Bacteria
| Measuring point | Inflow | Procedure | Reduction | log value |
|---|---|---|---|---|
| Start | 3 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.47 |
| 10% | 3 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.47 |
| 20% | 4 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.60 |
| 30% | 6 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.77 |
| 40% | 6 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.77 |
| 50% | 4 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.60 |
| 60% | 4 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.60 |
| 70% | 6 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.77 |
| 80% | 6 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.77 |
| 90% | 4 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.60 |
| 100% | 4 × 10⁷ / 100 ml | none detectable | 99.99999% | 7.60 |
MS2 coliphage · viruses
| Measuring point | Inflow | Procedure | Reduction | log value |
|---|---|---|---|---|
| Start | 4 × 10⁴ / ml | none detectable | 99.99% | 4.60 |
| 10% | 4 × 10⁴ / ml | none detectable | 99.99% | 4.60 |
| 20% | 6 × 10⁴ / mL | none detectable | 99.99% | 4.77 |
| 30% | 7 × 10⁴/ml | none detectable | 99.99% | 4.84 |
| 40% | 5 × 10⁴ / mL | 4 PFU/ml | 99.99% | 4.09 |
| 50% | 5 × 10⁴ / ml | 5 PFU/ml | 99.99% | 4.00 |
| 60% | 5 × 10⁴ / mL | 4 PFU/ml | 99.99% | 4.09 |
| 70% | 5 × 10⁴ / ml | 3 PFU/ml | 99.99% | 4.22 |
| 80% | 6 × 10⁴ / ml | 5 PFU/ml | 99.99% | 4.08 |
| 90% | 6 × 10⁴ / ml | 5 PFU/ml | 99.99% | 4.08 |
| 100% | 5 × 10⁴ / ml | 3 PFU/ml | 99.99% | 4.22 |
3 µm microspheres · protozoan surrogate
| Measuring point | Inflow | Procedure | Reduction | log value |
|---|---|---|---|---|
| Start | 52,300 / l | < 20 | 99.9% | 3.41 |
| 10% | 52,300 / l | < 20 | 99.9% | 3.41 |
| 20% | 51.400 / l | < 20 | 99.9% | 3.41 |
| 30% | 51.400 / l | < 20 | 99.9% | 3.41 |
| 40% | 51,400 / l | < 20 | 99.9% | 3.41 |
| 50% | 51,400 / l | < 20 | 99.9% | 3.41 |
| 60% | 51.400 / l | < 20 | 99.9% | 3.41 |
| 70% | 52,300 / l | < 20 | 99.9% | 3.41 |
| 80% | 52,300 / l | < 20 | 99.9% | 3.41 |
| 90% | 52.300 / l | < 20 | 99.9% | 3.41 |
| 100% | 52,300 / l | < 20 | 99.9% | 3.41 |
Why are these test organisms used?
Klebsiella terrigena · Bacteria
Klebsiella terrigena is used as a test organism for determining bacterial reduction performance. By deliberately contaminating the water with a high concentration, it is possible to reliably assess how effectively the filter retains bacteria.
MS2 coliphage · viruses
MS2 is a bacteriophage, meaning a virus that infects bacteria, and is used as a model virus to assess reduction performance against viruses. Due to its small size, MS2 is suitable as a challenging model organism for the standardized evaluation of virus reduction.
3 µm microspheres · protozoa
Defined microspheres with a size of 3 µm are used as standardized test particles to assess the reduction performance against larger microbiological contaminants such as protozoa. Their defined size enables controlled and reproducible testing of filter performance.
By combining these three test areas, the microbiological filtration performance of the Squeeze can be evaluated against different types and sizes of microbiological contaminants.
Classification of test results
The BACHGOLD Squeeze achieved at least Log 7 for bacteria, Log 4 for viruses, and Log 3 for protozoa over the entire tested filter capacity of 500 liters. This corresponds to a reduction of at least 99.99999% of bacteria, 99.99% of viruses, and 99.9% of protozoa. The filter performance remained consistent across all measurement points until the maximum filter capacity was reached.
Log 7, Log 4, and Log 3 mean: The concentration is mathematically reduced by a factor of at least 10 million for bacteria, 10,000 for viruses, and 1,000 for protozoa.
If you have any questions regarding the exam, please write to support@bachgold.ch.
