Evaluation of Puritii™ Water Filter for Removal of Biological and Chemical Contaminants
A summary of 2017 Laboratory Testing of Puritii Water Filters commissioned by ARIIX
Abstract/Exec Summary
Puritii Water Filters were challenged with microbiological (bacteria, virus and cryptosporidium oocyst analog) and chemical (inorganic, pesticides, VOCs et. al.) contaminants. The Puritii Water Filter removed greater than 99.95% of all microbiological contaminants, with the greatest reduction (>99.9999%) in the bacterial model.
Study Objective:
This study measured the effectiveness of the Puritii Water Filter in removing microbiological and chemical contaminants from water. The study was conducted by an ISO/IEC 17025:2005 accredited laboratory.
Study Design:
This study used a vacuum trap to draw water through the filter at a pressure of 3.4–3.6 inches of mercury. Ten liters of General Test Water (consisting of dechlorinated municipal water adjusted to NSF P231 guidelines) were drawn through each filter to condition it. Following conditioning of the filters, three (3) filters were used for each of the following contaminant categories:
- Microbiological, including bacteria, virus and fluorescent microspheres
- Inorganic (heavy metals, nitrates, copper, fluoride)
- Pesticides and Volatile Organic Carbon (VOC) compounds
- Additional Chemicals (Free Chlorine, Bisphenyl-A, Esterone and Ibuprofen)
For each challenge, one (1) liter of water containing the contaminant samples was used. Contaminant samples were prepared beforehand by adding the contaminant species to quantities of General Test Water.
Filter output was subsequently analyzed for contaminant content, and percent reduction was calculated by difference between pre-filtration and post-filtration contaminant concentrations.
Results:
Microbiological Tests:
For the Bacterial challenge, Raoultella terrigena was used. This organism is a member of the Enterobacteriaceae family, making it a useful analog for related bacterial pathogens in this family, including E. coli, Salmonella and Shigella. In this challenge, the Puritii filter successfully filtered an average of 99.9999% of the bacteria.
The Viral challenge used MS-2 bacteriophage. This virus infects members of the Enterobacteriaceae family and was used in this study because it is similar in size and shape to viruses which infect the human gastrointestinal tract. Puritii filtered out an average of 99.95% of this virus.
The Microbiological test also included the use of fluorescent microspheres measuring 3.0 micrometers in diameter, which were used as a surrogate for Cryptosporidium oocysts. Puritii filtered out more than 99.997% of these microspheres.
Table 1. Removal of Microbiological contaminants by Puritii Water Filter
Microbiological Species |
Starting Concentration |
Avg % Reduction |
Avg Output |
Bacteria (Raoultella terrigena)1 |
4.2 x 105 cfu/mL |
99.9999 |
<0.45 cfu/mL |
Virus (MS-2 Bacteriophage)2 |
5.7 x 105 pfu/mL |
99.95 |
295 pfu/mL |
3.0 µM Fluorescent microspheres3 |
3.3 x 104 particle/mL |
99.997 |
<1 particle/mL |
Inorganic Chemical Tests:
For Heavy Metals, this study evaluated the Puritii filter’s efficacy for removal of Arsenic, Lead and Mercury. The Puritii filter removed more than 99% of each of these species. Other metals evaluated included Copper and Chromium +6. Puritii filtered out more than 97.8% of the Copper and 59.3% of the Chromium +6.
In addition to these metals, Nitrates and Fluoride were evaluated as part of the inorganic chemical filtration tests. The Puritii filter removed 13% of Nitrates and 41.3% of Fluoride.
Table 2. Removal of Inorganic Chemical contaminants by Puritii Water Filter
Inorganic Chemical Species |
Starting Concentration |
Avg % Reduction |
Avg Output |
Arsenic (As) |
0.47 mg/L |
>99 |
0.0040 mg/L |
Chromium +6 (Cr) |
0.050 mg/L |
59.3 |
0.020 mg/L |
Lead (Pb) |
0.47 mg/L |
>99.3 |
0.0022 mg/L |
Copper (Cu) |
0.46 mg/L |
>97.8 |
0.00255 mg/L |
Mercury (Hg) |
410 µg/ L |
99.8 |
1 µg/L |
Nitrates |
23 mg/L |
13 |
20 mg/L |
Fluoride |
1.3 mg/L |
41.3 |
0.763 mg/L |
Pesticide Tests:
Several environmentally relevant pesticides were used to challenge the Puritii filter. For each of the species tested, Puritii effectively filtered >95%.
Table 3. Removal of Pesticide contaminants by Puritii Water Filter
Pesticide Species |
Starting Concentration (µg/L) |
Avg % Reduction |
Avg Output (µg/L) |
4,4'-DDT |
22 |
>95 |
<1.1 |
Aldrin |
27 |
>96.3 |
<1.1 |
Endosulfan I |
61 |
>98.2 |
<1.1 |
Endrin |
140 |
>99.2 |
<1.1 |
Heptachlor |
27 |
>96.3 |
<1.1 |
Lindane |
280 |
>99.6 |
<1.1 |
VOC Tests:
Various VOC species were tested, including organic solvents, polymer precursors and petroleum distillates. For all but two of these species, greater than 90% was filtered out. The remaining species (Acetone and Chloroform) were filtered at 77.9% and 74.5%, respectively. It is possible that these lower % reductions are due to the smaller size of the compounds in question.
Table 4. Removal of VOC contaminants by Puritii Water Filter
VOC Species |
Starting Concentration (µg/L) |
Avg % Reduction |
Avg Output (µg/L) |
1,2-Dibromo-3-Chloropropane |
450 |
99.5 |
2.5 |
Acetone |
83 |
77.9 |
18.34 |
Benzene |
420 |
97.8 |
9.24 |
cis-1,3-Dicholopropene |
420 |
94.8 |
21.84 |
Chloroform |
420 |
74.5 |
107.1 |
Isopropylbenzene |
400 |
>99.9 |
<0.52 |
Naphthalene |
830 |
>99.7 |
<2.5 |
Styrene |
420 |
>99.8 |
<0.98 |
Toluene |
400 |
99.6 |
1.6 |
O-Xylene |
430 |
>99.9 |
<0.50 |
Additional Chemical Tests:
In addition to the above tests, the removal of Free Chlorine, Bisphenyl-A (BPA), Esterone and Ibuprofen was evaluated, with the Puritii filter removing >97.9% of each of these.
Table 5. Removal of Additional Chemicals by Puritii Water Filter
Additional Chemical Species |
Starting Concentration |
Avg % Reduction |
Avg Output |
Free Chlorine |
2.01 mg/L |
>97.9 |
<0.01 mg/L |
BPA |
2.7 x 106 ng/L |
99.5 |
2350 (ng/L) |
Esterone |
3.8 x 105 ng/L |
99.6 |
1520 (ng/L) |
Ibuprofen |
4.9 x 106 µg/L |
99.5 |
2.4 x 104 (ng/L) |
Significance of Studies
This study showed that the Puritii filter can successfully filter many of the contaminants one would normally encounter in an on-the-go setting.
Conclusion
While the filter did not remove all contaminants presented in these studies, the Puritii Water Filter was shown to be effective at reducing all the species tested, with substantial (i.e. >90%) reductions for microbiological and chemical contaminants that one would encounter during daily use of the filter.
Addendum 2019: Additional Testing for Per- and Polyfluoroalkyl Substances (PFAS)
PFAS are man-made substances used in industrial processes. These can accumulate in the body, and studies have shown that this may adversely affect health (https://www.epa.gov/pfas). This study evaluated the detection of these compounds following Puritii filtration. Six samples were tested for each compound and in each case, compounds were either below minimum detection limits or detected but below reportable limits (i.e., Trace Detection).
PFAS Substance |
UNITS |
Reportable Limit |
Min. Detection Limit |
Undetected (# samples) |
Trace Detection (# samples) |
Perfluoroundecanoic Acid (PFUnA) |
ng/L |
20 |
3.7 |
6 of 6 |
|
Perfluorotridecanoic Acid |
ng/L |
20 |
3.2 |
5 of 6 |
1 of 6 |
Perfluorotetradecanoic Acid |
ng/L |
20 |
5.2 |
2 of 6 |
4 of 6 |
Perfluoropentanoic Acid (PFPeA) |
ng/L |
20 |
3.6 |
2 of 6 |
4 of 6 |
Perfluorooctane Sulfonate (PFOS) |
ng/L |
20 |
3.3 |
4 of 6 |
2 of 6 |
Perfluorooctane Sulfonamide (PFOSA) |
ng/L |
20 |
5.8 |
6 of 6 |
|
Perfluorononanoic Acid (PFNA) |
ng/L |
20 |
4.6 |
6 of 6 |
|
Perfluoro-n-Octanoic Acid (PFOA) |
ng/L |
20 |
5.3 |
6 of 6 |
|
Perfluorohexanoic Acid (PFHxA) |
ng/L |
20 |
4.6 |
2 of 6 |
4 of 6 |
Perfluorohexane Sulfonate (PFHxS) |
ng/L |
20 |
4 |
3 of 6 |
3 of 6 |
Perfluoroheptanoic Acid (PFHpA) |
ng/L |
20 |
4.7 |
6 of 6 |
|
Perfluoroheptane Sulfonate |
ng/L |
20 |
3.6 |
5 of 6 |
1 of 6 |
Perfluorododecanoic Acid (PFDoA) |
ng/L |
20 |
5.7 |
6 of 6 |
|
Perfluorodecanoic Acid (PFDA) |
ng/L |
20 |
6.6 |
6 of 6 |
|
Perfluorodecane Sulfonate |
ng/L |
20 |
4.3 |
6 of 6 |
|
Perfluorobutanoic Acid |
ng/L |
20 |
6.6 |
1 of 6 |
5 of 6 |
Perfluorobutane Sulfonate (PFBS) |
ng/L |
20 |
1.9 |
6 of 6 |
|
N-methylperfluorooctanesulfonamidol |
ng/L |
20 |
6.1 |
6 of 6 |
|
N-methylperfluorooctane Sulfonamide |
ng/L |
20 |
4 |
6 of 6 |
|
N-ethylperfluorooctane Sulfonamido Ethanol |
ng/L |
20 |
4.9 |
6 of 6 |
|
N-ethylperfluorooctane Sulfonamide |
ng/L |
20 |
5.3 |
6 of 6 |
|
MeFOSAA |
ng/L |
20 |
4.3 |
6 of 6 |
|
EtFOSAA |
ng/L |
20 |
4 |
6 of 6 |
|
6:2 Fluorotelomer sulfonate |
ng/L |
20 |
5.5 |
6 of 6 |
|
8:2 Fluorotelomer sulfonate |
ng/L |
20 |
6.5 |
6 of 6 |
|
These additional data show the effectiveness of the Puritii Water Filter in decreasing or eliminating PFAS from water, providing another reason to have confidence in the Puritii Water Filtration System.
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