Water · 20 minutes · Basic
Choose Water Treatment for the Hazard
Compare boiling, filters and disinfectants instead of assuming one bottle or filter handles every possible water hazard.
This is for educational purposes only. Not professional medical, electrical, or safety advice.
Warning
No single method covers every hazard. Ordinary boiling, iodine and camping filters do not make chemically contaminated water safe.
- 01
Separate germs from chemicals
Local advisories may describe microbial contamination or a chemical spill. Boiling treats germs but does not remove fuel, heavy metals or radioactive materials. A do-not-drink notice may require a different water source, not extra boiling.
- 02
Prefer boiling for germs
Where fuel and equipment allow, bring clear water to a rolling boil for 1 minute, or 3 minutes above 6,500 feet. Cool it in a covered container and keep it away from untreated water.
- 03
Read filter specifications
Look for independently supported claims for the organisms of concern. A cyst-rated filter addresses parasites such as Giardia and Cryptosporidium; many backpacking filters do not remove viruses. Carbon for taste is not the same as pathogen removal.
- 04
Pair methods when necessary
If boiling is unavailable, appropriate filtration followed by a labeled disinfectant can cover different microbial gaps. Follow both manufacturers' instructions; no improvised sand or charcoal filter is an equivalent replacement.
- 05
Account for iodine limitations
Iodine is not reliable against Cryptosporidium and is unsuitable during pregnancy, with thyroid disease or with a known treatment-product allergy. Use only a labeled water-treatment product for short-term use.
- 06
Keep a redundant plan
Store safe water, a treatment method and a backup that uses different supplies. Record filter replacement instructions, chemical expiration and required contact times on paper so they remain available with no signal.