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Potassium Iodide

  • Chemical Name: Potassium iodide
  • CAS No.: 7681-11-0
  • MF: KI
  • MW: 166
  • Purity: ≥98% or according to customer requested
  • Color: Yellow
  • Product Categories: Pharmaceutical raw materials;APIs;Hormones and the Endocrine System
  • Test method: HPLC


What is Potassium Iodide?

Potassium Iodide is a metal halide composed of potassium and iodide with thyroid protecting and expectorant properties. Potassium iodide can block absorption of radioactive iodine by the thyroid gland through flooding the thyroid with non-radioactive iodine and preventing intake of radioactive molecules, thereby protecting the thyroid from cancer causing radiation. In addition, this agent acts as an expectorant by increasing secretion of respiratory fluids resulting in decreased mucus viscosity.

It is a metal iodide salt with a K(+) counterion, a scavenger of hydroxyl radicals and a role as a radical scavenger and an expectorant. 

Basic information   

Product Name: Potassium iodide
Synonyms: Potassium iodide powder; KI; pharma grade Potassium iodide; Potassium Iodide USP; Potassium Iodide USP powder
CAS: 7681-11-0
MW: 166
EINECS: 231-659-4
Product Categories: Pharmaceutical raw materials; APIs; Hormones and the Endocrine System
Chemical Structure

Potassium iodide            

Chemical Properties    

Melting point 681 °C (lit.)
Boiling point 184 °C(lit.)
density 1.7 g/cm3
vapor density 9 (vs air)
vapor pressure 0.31 mm Hg ( 25 °C)
refractive index 1.677
Fp 1330°C
storage temp. 2-8°C
solubility H2O: 1 M at 20 °C, clear, colorless
form particles (round)
color Yellow
Specific Gravity 3.13
PH 6.0-9.0 (25℃, 1M in H2O)
Water Solubility 1.43 kg/L
Sensitive Hygroscopic
Stability: Stable. Protect from light and moisture. Incompatible with strong reducing agents, strong acids, steel, aluminium, alkali metals, brass, magnesium, zinc, cadmium, copper, tin, nickel and their alloys.
Potassium iodide Benefits

The effectiveness of KI as a specific blocker of thyroid radioiodine uptake is well established. When administered in the recommended dose, KI is effective in reducing the risk of thyroid cancer in individuals or populations at risk for inhalation or ingestion of radioiodines. KI floods the thyroid with non-radioactive iodine and prevents the uptake of the radioactive molecules, which are subsequently excreted in the urine.

Potassium Iodide side effects

Side effects are unlikely when KI is used at the recommended dose and for a short time. The following are possible side effects:

  • Skin rashes

  • Swelling of the salivary glands

  • “Iodism” (metallic taste, burning mouth and throat, sore teeth and gums, symptoms of a head cold, and sometimes upset stomach and diarrhea)

  • An allergic reaction can have more serious symptoms. These include fever and joint pains; swelling of parts of the body (face, lips, tongue, throat, hands, or feet); trouble breathing, speaking, or swallowing; wheezing or shortness of breath. Severe shortness of breath requires immediate medical attention.

Technical Support & Resources

Information provided in the product description is from published literature. Due to the nature of scientific experimentation, your results (e.g., selectivity and effective concentrations) or specific application for this product may differ. If you have questions about how this product fits your application, please contact our technical support staff.

MSDS: MSDS available.

COA: COA can be available if you send us inquiry.

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