Agencies | Governor
Search Virginia.Gov
Protecting You and Your Environment Virginia Department of Health
Home | VDH Programs | Find It! A-Z Index | Newsroom | Administration | Jobs

Potassium Iodine (KI)


Potassium iodide is a special kind of protective measure. Potassium iodide protects the thyroid gland against internal uptake of radioiodines that may be released in the unlikely event of a nuclear reactor accident.

The purpose of radiological emergency preparedness is to protect people from the effects of radiation exposure after an accident at a nuclear power plant. Evacuation or sheltering are the most effective protective measures in the event of a radiological emergency because it protects the whole body (including the thyroid gland and other organs) from all radionuclides and all exposure pathways.

Not all nuclear power plant accident scenarios may result in sufficient release of radioiodine to justify distribution of KI. Nuclear power plants are designed to remove certain radioactive materials during an accident such as radioiodine using filters and sprays to remove these materials; however, in ceratin types of accidents this may not always be possible.

Other than commercial nuclear power plant accidents, VDH would not consider the distribution of KI for other types of accidents involving radioactive materials, primarily because radioiodine would not be the radioisotope of concern.

The U.S. Nuclear Regulatory Commission (NRC) offered potassium iodine to the states for use in the 10 mile plume phase emergency planning zone (EPZ) of commercial nuclear power stations. The Commonwealth of Virginia accepted NRC's offer and stockpiled KI for distribution in responding to commercial nuclear power plant accidents.

VDH will recommend distribution of KI at Emergency Evacuation Centers (EAC) and to emergency workers when the projected radiation dose to the thyroid gland exceeds 5 rem.

KI is available in three forms:

Iosat 130 mg tablets in blister packs Manufactured by: Anbex, Inc. Website:

State Stock pile- Lot YXP7 Expires 09-2014

Primary use: Adults and adolescents weighing greater than 150 pounds

ThyroSafe 65mg tablets Manufactured by Recip Website:

Lot #: TU102A, Expiration Date: 3/2017.

Primary use: Small children and adolescents weighing less than 150 pounds


ThyroShield 65 mg per 1 ml liquid- Black raspberry flavor Manufactured by Fleming & Company Website:

Lot 0600614 Expired on 04/2011 and should be discarded.

Primary use: Infants and others unavailable to swallow pills

Other Information

See the following federal web sites:

U.S. Nuclear Regulatory Commission's web page on KI

U.S. Food and Drug Administration's (FDA) web site on radiation emergencies:

FDA Guidance: Potassium Iodide as a Thyroid Blocking Agent in Radiation Emergencies:

Center for Disease Control and Prevention:

Radiological Health Program | James Madison Building, 7th Floor | 109 Governor Street,  7th Floor | Richmond, VA  23219 | Telephone (804) 864-8150 | Fax: (804) 864-8165

Last Updated: 05-21-2012

Printable Version

E-mail This Page