Potassium iodate

Potassium iodate (KIO3) is a chemical compound. It is sometimes used in radiation treatment, as it can replace radioactive iodine from the thyroid. See potassium iodide for more information on this use.

Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.

Potassium iodate is an oxidizing agent and as such it can cause fires if in contact with combustible materials or reducing agents. It can be prepared by reacting a potassium-containing base such as potassium hydroxide with iodic acid, for example:

HIO3 + KOH → KIO3 + H2O

It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide.

3 I2 + 6 KOH → KIO3 + 5 KI + 3 H2O

Conditions/substances to avoid include: heat, shock, friction, combustible materials, reducing materials, aluminum, organic compounds, carbon, hydrogen peroxide and sulfides.

Use
Potassium iodate is used for iodination of table salt, because iodide can be oxidized to iodine under wet conditions by oxygen. To prevent this US companies add thiosulfates or other antioxidants to the potassium iodide, while in some other countries potassium iodate is used as source for iodine.