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ENTRY C-03Potassium iodide (KI): what it protects against and when to take it
Potassium iodide (KI) only protects the thyroid gland from radioactive iodine, says the FDA. It does not protect the rest of your body, and it does not protect against a dirty bomb. Take it only when local public health or emergency officials tell you to, and follow the package directions.
What KI does and does not do
| KI does | KI does not |
|---|---|
| Fills the thyroid with safe iodine so it cannot take in radioactive iodine | Protect any other part of your body |
| Help most for babies, children, and pregnant and breastfeeding women | Protect you from a dirty bomb or other radiation |
| Work alongside sheltering or evacuating | Replace getting inside or following evacuation orders |
From the FDA. South Carolina's health department adds that KI is not a replacement for evacuation or other protective orders (SC DHEC).
When to take it
- Not before an emergency and not "just in case". The FDA says take it only when local public health or emergency officials tell you to.
- Follow their instructions and the package directions exactly.
- More is not better. The FDA warns that taking more than directed, or more often, adds no protection and can cause serious harm.
- Your first job is still to get inside, stay inside and stay tuned (see C-01).
Who should check with a doctor first
The FDA says people with a known iodine sensitivity should not take it, and people with certain thyroid or heart conditions should avoid it or use it with caution. If you are unsure, ask your doctor now, before any emergency, so you know the answer if the moment comes.
Possible side effects include rash, swollen salivary glands, a metallic taste and stomach upset. Get emergency care for swelling of the face, lips or throat, or trouble breathing.
Buying it
- KI is sold without a prescription in the US, and only FDA-approved KI products are legally marketed (FDA). Check the product says FDA-approved.
- Table salt is not a substitute. The Southern Nevada Health District says it does not contain enough iodine to protect the thyroid.
- Store it with your emergency kit and note the expiry date.
Common mistakes
- Taking it early or daily as a precaution. Only take it when officials say so.
- Thinking it is a general anti-radiation pill. It only protects the thyroid.
- Doubling the dose for extra protection. The FDA says this can cause serious harm.
- Using table salt or iodine supplements instead.
- Buying a product that is not FDA-approved.
Gear for this
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FDA-approved potassium iodide tablets
The FDA says only FDA-approved KI products are legally marketed. Check the label says so before you buy.
NOAA Weather Radio
So you hear the official instruction to take KI, or not to.
Questions people ask
When should I take potassium iodide?
Only when local public health or emergency officials tell you to, following the package directions, says the FDA.
Does potassium iodide protect against all radiation?
No. The FDA says it only protects the thyroid from radioactive iodine, and does not protect against a dirty bomb.
Can I use iodized table salt instead of KI?
No. Health officials say table salt does not contain enough iodine to protect the thyroid.
Sources
- FDA: Frequently Asked Questions on Potassium Iodide (KI)
- Southern Nevada Health District: Radiation Emergencies and the use of Potassium Iodide
- South Carolina DHEC: Potassium Iodide (KI) FAQ
Related entries
- C-01What to do if a nuclear bomb goes offGet inside, stay inside, stay tuned. The official steps that save the most lives.
- C-02Radiation emergency: where to shelter in your home and for how longBasement or middle of the house, windows shut, air off, at least 24 hours.
- C-04Dirty bomb: what it is and what to doIt is not a nuclear bomb. The blast is the main danger. Get inside, stay inside, stay tuned.
General safety information only, not medical or professional advice. Rules can change, so check the linked sources and follow your local officials. As an Amazon Associate I earn from qualifying purchases.