Potassium chloride
[CAS# 7447-40-7]

Identification

• Classification: API >> Water, electrolyte and acid-base balance regulator >> Electrolyte balance regulator
• Name: Potassium chloride
• Molecular Formula: KCl
• Molecular Weight: 74.54
• CAS Registry Number: 7447-40-7
• EC Number: 231-211-8
• SMILES: [Cl-].[K+]

Properties

• Density: 1.984
• Melting point: 770 °C
• Sublimation: 1500 °C
• Boiling point: 1420 °C
• Water solubility: 340 g/L (20 °C)

Safety Data

• Hazard Symbols: Xi
• Risk Statements: R36
• Safety Statements: S26;S39

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Chronic hazardous to the aquatic environment	Aquatic Chronic	3	H412
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - repeated exposure	STOT RE	2	H373
Specific target organ toxicity - single exposure	STOT SE	3	H335
Flammable liquids	Flam. Liq.	2	H225
Skin corrosion	Skin Corr.	1B	H314
Skin irritation	Skin Irrit.	2	H315
Acute toxicity	Acute Tox.	4	H302
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411

Discovery and Applications

Potassium chloride is a naturally occurring salt composed of potassium and chlorine with the chemical formula KCl. It was first discovered in the 19th century and has been extensively studied and utilized since then. KCl occurs in nature as potassium salts, often in association with other salts in evaporite deposits. Its high solubility in water makes it an essential ingredient in a variety of applications.

Potassium chloride is essential for maintaining electrolyte balance in the human body. It is widely used medically to treat or prevent hypokalemia (low potassium levels), a condition that can lead to muscle weakness, heart rhythm disturbances, and other health problems. KCl is administered orally or intravenously to replenish potassium levels and restore normal cell function. As a dietary supplement, potassium chloride helps individuals meet their daily potassium needs, especially when dietary intake is inadequate. It is often included in potassium tablets and powders to support cardiovascular health, nerve function, and muscle contraction. In emergency medical situations, KCl is used in a controlled environment to treat severe hypokalemia and stabilize heart rhythm. It is an important component of life-saving protocols in critical care settings.

The main application of potassium chloride is in agriculture, where it is the primary source of potassium in fertilizers. KCl, known as potassium chloride (MOP), provides essential potassium for plant growth to improve crop yield, quality and disease resistance. Potassium is a key nutrient that supports plant water regulation, enzyme activation and photosynthesis. Potassium chloride is also used to improve potassium-deficient soils, improving soil fertility and promoting healthier plant growth. By providing readily available potassium, potassium chloride helps maintain optimal soil nutrient levels, ensuring sustainable agricultural practices.

In the food industry, potassium chloride is used as a salt substitute to reduce sodium content in processed foods. It provides a salty taste without the health risks associated with high sodium intake, making it a valuable ingredient in low-sodium products. Potassium chloride is used to produce a variety of potassium compounds and chemicals. Its reactivity and solubility make it suitable for manufacturing processes in industries such as glass production, dyeing and pharmaceuticals. Potassium chloride is used as a sodium chloride substitute in water softening systems. It helps replace calcium and magnesium ions in hard water, reducing scaling and improving the efficiency of water-using equipment while providing a lower sodium alternative.

Potassium chloride is safe when used appropriately in a variety of applications. In agriculture, proper application rates are essential to avoid potential soil salinization. In medicine, potassium chloride must be administered with caution to avoid harmful hyperkalemia (excessive potassium levels). Environmental guidelines ensure its safe handling and use, minimizing adverse effects. Importance in all areas of industry.

References

2025. Impact of NaCl substitution with KCl on the lipid oxidation in oil-in-water emulsions. Food Chemistry, 468.
DOI: 10.1016/j.foodchem.2024.142154