E917 - potassium iodate

At a glance

• What it is: an iodine-containing compound used in foods, especially in iodized salt.
• Main roles: helps prevent iodine deficiency; can strengthen dough in bread-making.
• Where you’ll find it: iodized table salt; occasionally in bread flours or mixes (depends on local rules).
• Taste/texture: used at tiny levels that don’t change flavor; as a dough improver it can make dough stronger and bread volume more consistent.
• Common alternatives: ascorbic acid, alpha-amylase, L-cysteine, DATEM, lecithins.
• Safety: appropriate for iodized salt when used at regulated levels; very high iodine intakes can affect the thyroid.
• Regulations vary by country; always check local labeling.

Why is potassium iodate added to food?

Two reasons drive its use. First, it supplies iodine to prevent deficiency when added to table salt; potassium iodate is preferred in many climates because it is more stable than iodide in salt during storage and transport.¹ Second, it can act as a flour treatment agent (oxidizer) that strengthens dough and improves bread volume in jurisdictions that allow this use.²

What foods contain potassium iodate?

• Iodized table salt: Many national salt standards allow iodization with potassium iodate or potassium iodide; the label may list “potassium iodate” among ingredients.³
• Bread and rolls: Some places permit potassium iodate as a dough conditioner; where used, it may appear in flour treatments or bakery premixes (levels are very small). Practices differ by country and by brand.

What can replace potassium iodate?

Bakers often choose other dough improvers:

• Antioxidant/oxidizing systems like ascorbic acid
• Enzymes such as alpha-amylase
• Amino acids like L-cysteine
• Emulsifiers including DATEM and lecithins
• Mineral conditioners such as calcium sulphate Historically, oxidizers like potassium bromate and azodicarbonamide were also used in some regions, but many bakers have moved away from them.

For salt fortification, some programs use calcium iodate or potassium iodide depending on stability needs and local regulations.

How is potassium iodate made?

Industrial production typically oxidizes iodine or iodide to form iodate, followed by purification to food grade. It is a white, odorless, crystalline solid and a strong oxidizing agent.⁴ When used in foods under U.S. regulation, it must meet purity specifications such as those in the Food Chemicals Codex (FCC).²

Is potassium iodate safe to eat?

When used to fortify salt, potassium iodate is considered safe and effective at regulated iodine levels. Global guidance sets fortification ranges to deliver adequate iodine while avoiding excess, and notes iodate’s better stability in salt compared with iodide in many settings.¹ As with any iodine source, consuming too much can disturb thyroid function; health authorities set upper limits for daily iodine intake to reduce this risk.⁵

Does potassium iodate have any benefits?

Yes—its primary public health benefit is preventing iodine deficiency when used to iodize salt. Adequate iodine supports normal thyroid hormone production, growth, and brain development; iodized salt programs have helped reduce deficiency disorders worldwide.⁶

Who should avoid potassium iodate?

• People advised to follow a low-iodine diet (for example, before certain thyroid tests or treatments) should avoid iodized salt and other iodine sources for a short period as directed by their clinician.⁵
• Individuals with specific thyroid conditions may be sensitive to high iodine intakes and should seek medical guidance on iodine sources and amounts.⁵

Myths & facts

• Myth: Iodized salt always uses potassium iodide, never iodate. Fact: Many standards allow either potassium iodate or potassium iodide; programs choose based on stability and local conditions.³
• Myth: You can taste potassium iodate in salt. Fact: At fortification levels, it does not give salt a noticeable taste.
• Myth: More iodine is always better. Fact: Both too little and too much iodine can affect the thyroid; fortification targets a safe, effective range.⁵
• Myth: All bread contains potassium iodate. Fact: Its use in bread varies by country and manufacturer; many bakers use other dough improvers instead.

potassium iodate in branded foods

• Iodized salt: Depending on the country, some retail salts list “potassium iodate” on the ingredient panel. Others use potassium iodide—check the label.
• Bakery items: If permitted locally, certain flours, premixes, or breads may include potassium iodate as a dough conditioner, but this is uncommon in many markets today.
• How to check: Look for “potassium iodate,” “E917,” or “iodate” in the ingredient list. For iodine intake, the nutrition label (or the salt pack panel) may also indicate that the product is iodized.

References

Footnotes

1. Guideline: Fortification of food-grade salt with iodine for the prevention and control of iodine deficiency disorders — World Health Organization. https://www.who.int/publications/i/item/9789241507929 ↩ ↩²

2. 21 CFR §172.375 Potassium iodate — U.S. Code of Federal Regulations (eCFR). https://www.ecfr.gov/current/title-21/chapter-I/subchapter-B/part-172/subpart-D/section-172.375 ↩ ↩²

3. Standard for Food Grade Salt (CXS 150-1985) — Codex Alimentarius (FAO/WHO). https://www.fao.org/fao-who-codexalimentarius/standards/list-of-standards/en/ ↩ ↩²

4. Potassium iodate — PubChem, National Library of Medicine (NIH). https://pubchem.ncbi.nlm.nih.gov/compound/Potassium-iodate ↩

5. Iodine Fact Sheet for Health Professionals — NIH Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/ ↩ ↩² ↩³ ↩⁴

6. Iodine | Micronutrient Facts — Centers for Disease Control and Prevention (CDC). https://www.cdc.gov/nutrition/micronutrients/iodine/index.html ↩