Geoscience Reference
In-Depth Information
Tincture of Iodine
Eight drops of 2 percent tincture of iodine (Salvato 1982, 372) can be used to disinfect 1 quart
of clear water (8 milligrams per liter dose). Allow water to stand at least thirty minutes before it
is used. Studies of the usefulness of elemental iodine show it to be a good disinfectant over a
pH range of 3 to 8. It is effective against enteric bacteria, amoebic cysts,
Cerariae
,
Leptospira
,
and viruses within thirty minutes.
Iodine Tablets
The use of tetraglycine hydroperiodide tablets is an effective method of disinfecting small
quantities of water. Tetraglycine hydroperiodide tablets sell under the brand names of Glob-
aline, Portable-Agua, and Coghland's. Iodine tablets are handy, compact, and light. The tablets
are very effective as a water disinfectant if directions are correctly followed. If the water to be
treated is cloudy, it should be filtered or treated with double the number of iodine tablets.
You can purchase Portable-Agua with vitamin C-based taste-neutralizer tablets to totally
eliminate the iodine aftertaste. Tablets can be purchased from pharmacies, preparedness/surviv-
al suppliers, and sporting goods stores. Once opened, iodine tablets have a shelf life of up to
one year.
Iodine Crystal Solution
You can purchase a handy, ready-made iodine crystal water-treatment kit from Polar Pure (in-
cludes crystals and bottle with thermometer), or you can make your own iodine crystal solution
with about 5 grams (1⁄5 ounce) of iodine crystals and a 2-ounce glass bottle. The Polar Pure kit
treats about 500 gallons of water for about $10. Cover the crystals with a small amount of wa-
ter to preserve them from evaporation (sublimation).
When you are ready to use the iodine solution, fill the 2-ounce bottle with water, put the
cap on, and shake the bottle for several minutes. Let the heavy crystals settle, then carefully
pour out approximately 3 tablespoons (almost all the solution) into 1 gallon of clear water.
Use
only the iodine solution: leave the crystals in the bottle (the crystals are poisonous).
Stir the
water, and let it stand for approximately thirty minutes. If the water is very cold, let it stand for
1 hour.
You can use the crystals up to about 300 times before they completely dissolve. Be sure to
label the bottle “Poison” and keep it out of reach of children. Elemental iodine is poisonous by
ingestion (in concentrated form). Elemental iodine crystals are inexpensive and can be obtained
at pharmacies and chemical supply companies.
