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San Luis Obispo County, California


Potassium Iodide Information (KI)



Should a nuclear power plant emergency occur that involves a release of radiation, local and state officials may ask residents who live near the affected area to evacuate or shelter-in-place as a public safety measure. Potassium Iodide (KI) tablets may be taken as a supplemental protective measure in some situations.

Potassium iodide is not an "anti-radiation" pill. It is only a supplemental protective measure, secondary to evacuation or sheltering in place. Evacuation and sheltering in place remain the primary protective actions during a radiological emergency. Potassium iodide protects the thyroid gland against exposure to radioactive iodine in the unlikely event of a radiation release from a nuclear power plant emergency. If taken in an appropriate and timely dosage, potassium iodide can block exposure of the thyroid gland to radioactive iodine. However, potassium iodide does not protect other parts of the body from exposure to other contaminants released during the emergency.

Potassium iodide should only be taken after specific instruction by a state or local public health official.

Additional information is available on the California Governor's Office of Emergency Services website at:


Obtaining KI -
If you live or work in the Diablo Canyon Emergency Planning Zone, you may obtain KI for your household. 
Click here for the KI Voucher

Visit the San Luis Obispo Public Health Department website for more information.

KI will not be distributed during an emergency, so please plan ahead.

Liquid KI Info
Information regarding liquid potassium iodide can be obtained from your physician and is also available on the following websites:

Centers for Disease Control and Prevention:




 Frequently Asked Questions:

 Who can take potassium iodide?
Most people can take potassium iodide without side effects. A small number of people could have an adverse reaction. Anyone with an existing thyroid gland condition or anyone allergic to iodine should NOT take it. Consult your physician if unsure whether you should take potassium iodide.
Is taking potassium iodide mandatory?
No. The use of potassium iodide is voluntary. No one is required to accept it or use it.

Where can potassium iodide be purchased?
Potassium iodide can be ordered from several commercial manufactures by telephone, mail, or via the Internet. You may call the following numbers for information regarding FDA approved products.

  • Iosat (Anbex, Inc.), 1-866-463-6754.
  • Thyroshield, (636) 343-8200


How Much KI to Take


How Much

Potassium Iodide (KI) to Take

One Tablet = 65 milligrams of KI

Adults 18 Years and Older Two Tablet
Pregnant or Nursing Women Two Tablet
Adolescents 12-18 Years Old One to Two Tablets*
Children 3-13 Years Old One Tablet
Children 1 Mo. to 3 Years Old Half Tablet
Infants, Birth to 1 Month Quarter Tablet

* Adolescents approaching adult size (equal to or greater than 150 pounds) should receive the full adult dose.

















For more information contact:
California Governor's Office of Emergency Services
3650 Schriever Avenue
Mather, CA 95655


US Food and Drug Administration (FDA) Center for Drug Evaluation and Research, Division of Pharmaceutical Analysis.

FDA, Guidance: Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies, December 2001.