Other names for the additive (synonyms)
General information
Potassium iodate is an inorganic compound with strong oxidizing properties, used in the food industry as a food additive E917. According to the Codex Alimentarius: CXG 36-1989, the additive has the code INS 917.
Its main area of application is the baking industry, where additive E917 acts as a flour treatment agent, helping strengthen the gluten structure of dough and improving its elasticity and stability during processing and baking. In addition, potassium iodate is widely used in the iodization of table salt as a stable and effective source of iodine.
Additive E917 has a synthetic origin. Under natural conditions, potassium iodate does not occur in its ready form, although iodine as a chemical element is naturally present and widely distributed in the environment.
The use of iodine compounds in nutrition became widespread in the early 20th century after their role in preventing iodine deficiency disorders was established.
In the mid-20th century, potassium iodate also began to be used in the baking industry as a fast oxidizing agent to strengthen dough gluten, which made it possible to significantly intensify industrial bread production.
The chemical formula of potassium iodate is KIO3. Additive E917 appears as a white crystalline powder with no odor, highly soluble in water and possessing strong oxidizing properties. It also has good thermal stability and resistance to light.
In the food industry, potassium iodate is produced synthetically. The main industrial method is the electrochemical oxidation of potassium iodide solution. Another common method is the oxidation of elemental iodine with potassium chlorate or hydrogen peroxide in an alkaline medium. The resulting crystals undergo repeated recrystallization and drying to meet food safety standards.
Effect on the body
Benefits of additive E917
After entering the body, potassium iodate is reduced to iodide and is excreted mainly through the kidneys.
Additive E917 serves as a source of iodine, a trace element essential for the normal functioning of the thyroid gland and hormonal balance. Iodine is a component of thyroid hormones (thyroxine T₄ and triiodothyronine T₃), which regulate metabolism, energy balance, nervous system development, and growth in children. Adequate iodine intake from food reduces the risk of iodine deficiency disorders such as goiter and hypothyroidism, as well as related developmental disorders in children and pregnant women.
Risks of additive E917
The main risk of potassium iodate is related to its strong oxidizing capacity and the possibility of excessive iodine intake. As a powerful oxidizing agent, it may irritate the mucous membranes of the digestive tract and, at high doses, cause oxidative stress in cells.
Studies on mice showed that excess KIO₃ may alter oxidative stress and immune cell development in the thyroid gland, which is associated with the risk of autoimmune reactions.
Excessive intake of this additive is particularly dangerous for people with hyperthyroidism, autoimmune thyroiditis, or iodine-induced disorders, as it may trigger exacerbation of thyroid diseases (Jod-Basedow effect).
Clinical cases also describe that high doses of potassium iodate may cause toxic damage to the retina with acute vision loss.
The acceptable daily intake of iodine is approximately 0.1 mg per kg of body weight per day, considering all iodine sources.
The European Food Safety Authority (EFSA) established recommended intake (AI) levels of iodine: 150 µg/day for adults, 200 µg/day for pregnant and breastfeeding women, and from 90 µg/day (1–6 years) to 150 µg/day (11–14 years) for children. The upper intake level (UL) is 600 µg/day for adults and from 200 to 500 µg/day for children depending on age.
Uses
In the food industry, additive E917 is used as a source of iodine and as a flour treatment agent in baking, as well as for iodization of table salt.
Legal Status
The use of food additive E917 is strictly regulated, and its concentration in food products is controlled according to established iodine intake standards.
Currently, additive E917 is practically not used in European Union countries, particularly as a flour treatment agent, due to revised food safety approaches and the introduction of alternative technologies. It is not listed in Regulation (EC) No 1333/2008, but it is included in the Codex Alimentarius international food additive numbering system: CXG 36-1989.
In several countries, including the United States, Ukraine, Canada, and Japan, the use of potassium iodate is permitted in limited applications, mainly for iodization of table salt or as a technological additive in baking, provided good manufacturing practice and strict dosage control are followed.