SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/trav-filter-virus

Most portable water filters on trips remove parasites. What do they NOT reliably remove?

Most filters miss viruses.

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  1. Sand
  2. Viruses and some bacteria ✔
  3. Parasites

Why: CDC says most portable filters will not remove viruses or all bacteria. Reverse osmosis filters can. Boiling or chemical treatment covers what a filter misses.

Huh, didn't know that: CDC says certified NSF 53 or 58 filters remove parasites if used properly.

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References

Answer: Viruses and some bacteria. CDC says most portable filters will not remove viruses or all bacteria. Reverse osmosis filters can. Boiling or chemical treatment covers what a filter misses.

  1. CDC Travelers' Health: Water Disinfection wwwnc.cdc.gov/travel/page/water-disinfection
    It will not remove viruses or all bacteria
    Checked 2026-10-10.

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