About KI Tablets

About KI Tablets - Potassium Iodide

The Canadian Nuclear Safety Commission (CNSC) — the federal agency that monitors the safe operation of nuclear stations — now requires that all homes and businesses within 10 km of a nuclear power station receive a supply of potassium iodide (KI) pills. The pills have been available free of charge at select pharmacies, but will now be sent by mail due to increased safety standards.

In the very unlikely event of a nuclear emergency and a release of radioactive iodine to the public, KI pills will help prevent the development of thyroid cancer, and are especially effective at safeguarding children's thyroid glands. It is important for each household to have a supply of these pills because they are most effective if taken just before or soon after exposure to radioactive iodine.

The distribution of KI pills is not due to any change in the risk of a nuclear emergency and is not meant to cause alarm. We believe that staying safe means being prepared, even for the most unlikely of events.

What do I do?

  • The letters and pills were mailed by postal code and in some cases by road boundaries, which means some homes beyond 10 km received the KI pill package.


Enter your postal code to see if you’re within the eligible zone of a nuclear generating station.


Please enable JavaScript to access the Locator functionality.

Sort By:  
Lot: 306010A Expiry 6/2020 . (Get 50% off when you Apply the Coupon 5555)
$57.46  Inc Tax
RADBLOCK 200 65MG SCORED COATED 6/20 (Get 50% off when you Apply the Coupon 5555) (RADB200S)


Threshold Thyroid Radioactive Exposures and 
Recommended Doses of KI for Different Risk Groups

 Predicted Thyroid exposure(cGy)KI dose (mg)# of 130 mg tablets# of 65 mg tablets
Adults over 40 yrs>50013012
Adults over 18 through 40 yrs>10
Pregnant or lactating women> 5
Adoles. over 12 through 18 yrs*651/21
Children over 3 through 12 yrs
Over 1 month through 3 years321/41/2
Birth through 1 month161/81/4

(The tabled information is provided courtesy of the Nuclear Regulatory Commission).




RadBlock Archive PDF


Back to KI Canada home page 

Frequently Asked Questions About Potassium Iodide

In Canada, Health Canada, or in the United States, the FDA, is the Federal agency responsible for decisions about appropriate thresholds and dosages for use of potassium iodide:

What is potassium iodide?

Potassium iodide is a salt, similar to table salt.  Its chemical symbol is KI.  It is routinely added to table salt to make it 'iodized'. Potassium iodide,if taken in time and at the appropriate dosage, blocks the thyroid gland's uptake of radioactive iodine and thus could reduce the risk of thyroid cancers and other diseases that might otherwise be caused by exposure to radioactive iodine that could be dispersed by a terrorist activity or nuclear accident.

What is the role of potassium iodide in radiological emergency preparedness?

The purpose of radiological emergency preparedness is to protect people from the effects of radiation exposure after a dirty bomb or accident at a nuclear power plant.  Evacuation is the most effective protective measure 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.  However, in situations when evacuation is not feasible and in-place sheltering is substituted as an effective protective action, administering potassium iodide is a reasonable, prudent, and inexpensive supplement to evacuation and sheltering.

Potassium iodide is a special kind of protective measure in that it offers very specialized protection.  Potassium iodide protects the thyroid gland against internal uptake of radioiodines that may be released in the unlikely event of nuclear exposure.

What is the benefit of taking potassium iodide during a radiological accident?

When potassium iodide is ingested, it is taken up by the thyroid gland.  In the proper dosage, and taken at the appropriate time, it will effectively saturate the thyroid gland in such a way that inhaled or ingested radioactive iodines will not be accumulated in the thyroid gland.  The risk of thyroid effects is reduced.  Such thyroid effects resulting from radioiodine uptakes due to inhalation or ingestion, or both, could result in acute, chronic, and delayed effects.  Acute effects from high doses include thyroiditis, while chronic and delayed effects include hypothyroidism, thyroid nodules, and thyroid cancer.

Can individual members of the public obtain potassium iodide?

Health Canada has approved potassium iodide as an over-the-counter medication.  As with any medication, individuals should check with their doctor or pharmacist before using it.

What are the recommended dosages of potassium iodide?

Look at the chart above...

Lot: 306010A Expiry 6/2020 . (Get 50% off when you Apply the Coupon 5555)
$57.46  Inc Tax
Per Page      1 - 1 of 1
  • 1