Tincture of iodine

Tincture of iodine is usually 10% elemental iodine in ethanol, although it is also available in 2%, 3%, and 7% mixtures. It is an essential component of any emergency survival kit, used both to disinfect wounds and to sanitize surface water for drinking.

When alcohol solution is not desirable, Lugol's iodine, an aqueous solution of iodine in potassium iodide solution, or povidone-iodine (Betadine), a PVPI solution, can be used.

It can also be used to detect and treat iodine deficiency which can lead to hypothyroidism.

Iodine is toxic. Children and pregnant women, who are more sensitive to it, should avoid its use. Human metabolism requires trace amount of Iodine, which is satisfied by iodised salt.

When using iodine to sanitize surface water, it should be left to sit for 30 minutes before drinking, allowing time for all viruses and bacteria to be killed. If the water temperature is less than 20 °C (68 °F), sitting time should be extended to several hours. To purify 1 L (34 oz) of water, 0.3 mL (0.01 oz) of 2% tincture should be used. Cold or cloudy water should be given 2.4 mL (0.08 oz) of 2% iodine, and should be left to sit for several hours.

Iodine used to sanitize water is also available in tablet or crystal form. One form or another should be available at health stores, and trip outfitters.