Potassium Sorbate: A Widely Used Food Preservative

CAS Registry Number: 24634-61-5 

Note: An alternative CAS number, 590-00-1, is also associated with this compound in some sources. 

Overview

Potassium sorbate is the potassium salt of sorbic acid, with the chemical formula C₆H₇KO₂ and a molecular weight of 150.22 g/mol.  It appears as a white crystalline powder that is highly soluble in water (58.2% at 20°C), making it particularly useful in aqueous applications.  While sorbic acid occurs naturally in some berries, commercial potassium sorbate is produced synthetically by neutralizing sorbic acid with potassium hydroxide. 

Major Applications

Food and Beverage Industry

Potassium sorbate is primarily used as a food preservative (E number E202) to inhibit the growth of mold, yeast, and some bacteria, thereby extending product shelf life.  It is effective at low concentrations and works best in slightly acidic conditions.  Its high water solubility and neutral taste make it a favored choice across numerous applications. 

Common food applications include:

• Processed meats, poultry, and seafood products

• Baked goods, cheese, and dried fruits

• Beverages, fruit juices, and soda 

• Soy sauce, ketchup, and other condiments 

Pharmaceuticals and Cosmetics

Potassium sorbate is also used as a preservative in pharmaceutical products, cosmetics, and personal care items.  Its function in these products is to prevent microbial contamination and extend shelf stability. 

Safety Information

General Safety Status

Potassium sorbate is generally regarded as a safe preservative by regulatory authorities worldwide.  In the human body, it breaks down into water and carbon dioxide without accumulation.  Historical safety assessments have concluded it is safe for use as a cosmetic ingredient at concentrations up to 1%. 

Potential Health Concerns

Despite its widespread approval, some studies have raised concerns about potential health risks associated with long-term or high-dose exposure:

• Hepatotoxicity and Carcinogenicity: A recent 2025 study using network toxicology and molecular docking identified 124 potential targets for hepatotoxicity and 106 for carcinogenicity.  In vitro cell experiments demonstrated dose-dependent toxicity to liver cells (LO2 cells), with elevated markers of liver damage (ALT, AST, LDH) and increased oxidative stress (ROS) and apoptosis at higher concentrations.  Some historical studies have suggested that high doses of potassium sorbate could induce liver cancer by depleting glutathione levels in the liver and generating mutagens in the gut. 

• Genetic and Reproductive Effects: Mutagenicity test results have been mixed, with some assays showing positive and others negative results.  However, no teratogenic effects were observed in pregnant mice and rats administered potassium sorbate. 

Irritation and Sensitization

At higher concentrations, potassium sorbate is an irritant to the skin, eyes, and respiratory system (classified as Xi with R36/37/38 risk statements).  However, at concentrations up to 10%, it was found to be practically non-irritating to rabbit eyes and at most only slightly irritating to skin.  Sensitization rates in human repeat insult patch tests have been low (0% to 0.8%).