Potassium iodate

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:[1]

HIO₃ + KOH → KIO₃ + H₂O

It can also be prepared by adding iodine to a hot, concentrated solution of potassium hydroxide:[1]

3 I₂ + 6 KOH → KIO₃ + 5 KI + 3 H₂O

Or by fusing potassium iodide with potassium chlorate, bromate or perchlorate, the melt is extracted with water and potassium iodate is isolated from the solution by crystallization:[2]

KI + KClO₃ → KIO₃ + KCl

The analogous reaction with potassium hypochlorite is also possible:[3]

KI + 3KOCl → 3KCl + KIO₃

Conditions/substances to avoid include: heat, shock, friction,[4] combustible materials,[1] reducing materials, aluminium,[4] organic compounds,[1] carbon, hydrogen peroxide and sulfides.[4]

Potassium iodate is sometimes used for iodination of table salt to prevent iodine deficiency. In the US, iodized salt contains antioxidants, because atmospheric oxygen can oxidize wet iodide to iodine; other countries simply use potassium iodate instead.[5] Potassium iodate is also an ingredient in some baby formula.[6]

Like potassium bromate, potassium iodate is occasionally used as a maturing agent in baking.[7]

Radiation protection

An unopened box of potassium iodate tablets distributed in the early 2000s to Irish households in case of a terror attack on British nuclear facilities.

Potassium iodate may be used to protect against accumulation of radioactive iodine in the thyroid by saturating the body with a stable source of iodine prior to exposure.[8] Approved by the World Health Organization for radiation protection, potassium iodate (KIO₃) is an alternative to potassium iodide (KI), which has poor shelf life in hot and humid climates.[9] The UK, Singapore, United Arab Emirates, and the U.S. states Idaho and Utah all maintain potassium iodate tablets towards this end. Following the September 11 attacks, the government of Ireland issued potassium iodate tablets to all households for a similar purpose.[10]

Recommended Dosage for Radiological Emergencies involving radioactive iodine[11]

Age	KI in mg	KIO3 in mg
Over 12 years old	130	170
3 – 12 years old	65	85
1 – 36 months old	32	42
< 1 month old	16	21

Potassium iodate is not approved by the U.S. Food and Drug Administration (FDA) for use as a thyroid blocker, and the FDA has taken action against US websites that promote this use.[12][13]