Survival guides · Water & Food

Use Purification Tablets

WHEN TO USE THISLight, portable, and easy — if they're in your kit.

1. Know what you have

   • Chlorine dioxide tablets are the most effective.
   • Iodine tablets work, but not for pregnancy, thyroid problems, or more than a few weeks.
   • Check the date — expired tablets are weaker.

2. Clear the water

   • Cloudy? Pour it through a cloth or bandana first.
   • Cleaner water in, safer water out.

3. Dose and wait

   • Follow the package exactly — doses vary.
   • Chlorine dioxide: usually 1 tablet per liter, 30 minutes — 4 hours to kill Cryptosporidium.
   • Iodine: usually 30 minutes.
   • Cold or cloudy water needs longer.

Sources: CDC Water Treatment Methods · EPA Drinking Water Advisories

General information to help in an emergency — not a substitute for training or professional care.