Iodine

mod hazard

Also: Lugol’s 2%, tincture of iodine 2%, povidone-iodine 10% (Betadine-type)

First aidWater

A classic antiseptic and a backup water disinfectant. Thyroid disease, pregnancy, and some allergies take iodine off the table — have bleach or boiling as the real plan.

Shelf life: 3–5 years typical in amber glass; longer if still dark and capped
Container: Amber glass. Iodine crawls through plastic and stains everything.
Grade: USP. Know whether you have tincture (alcohol), Lugol’s (iodide in water), or povidone-iodine.

What it does

▸Skin antiseptic (povidone-iodine is gentler than old tincture)
▸Backup water disinfection with tincture / elemental iodine (not povidone-iodine)

Store

▸Amber glass, child-locked, away from metals it will corrode.

Hazards

▸Stains. Irritates tissue if overused.
▸Not for people with iodine allergy, some thyroid conditions, or pregnancy without a clinician.
▸Povidone-iodine is not a drinking-water drop.

Never mix

Household bleach Calcium hypochlorite Activated charcoal

Gear

Gloves — it stains skin for days

In the field

Water backup with 2% tincture (common field rule of thumb): 5 drops per quart of clear water, 10 if cloudy; wait 30 minutes. This is a backup, not the primary method. Confirm the exact percent on your bottle before you need it, and write the math on the label tonight.

Source

Pharmacy. Prefer povidone-iodine for skin and a dedicated water kit (or bleach) for drinking.