I would like to advise that there could be potential health risks with using "hollow fiber" microfilter products related to efficacy.
Hollow fiber manufacturers (that actually produce hollow fiber filter modules used by end product manufacturers) may have issues shipping significant numbers (percentages)of faulty filters. If the secondary manufacturer even knows about it, they are having to do some sort of good/bad sorting process. There are issues with air particle and bubble point testing reliability. Secondary sampling and testing is necessary to validate air particle or bubble point testing reliability, such as with the use of microbiological testing. If microbiological testing is being used, live "bugs" may be used to test actual filters for failures that make it through to the clean water side. If microbiological testing should be used only for testing and then filters should be properly disposed of as bio waste.
Anyone that believes they have been made ill after using a "hollow fiber" filter should contact the place of purchase and manufacturer, as well as EPA/FDA/CPSC.
It is recommended that users of "hollow fiber" microfilters add a purifier of some sort to filtered water, or do not use.
Here are some questions users should ask manufacturers and retailers on behalf of their vendors:
1. Are they having to sort good/bad filters from vendors upon arrival?
2. If so, what sorting process is used (air particle, bubble point, microbio)?
3. What standards certification do they have for these sorting processes?
4. Have there been any unofficial recalls or other problems with this product?
5. Is microbiological testing being used?
6. If so, what bacteria or viruses are being used?
7. Are filters that have been microbiologically tested being sold to the public?
industry insider.

