Potassium persulfate
[CAS# 7727-21-1]

Identification

• Classification: Inorganic chemical industry >> Inorganic salt >> Metal sulfides and sulfates
• Name: Potassium persulfate
• Synonyms: Potassium peroxydisulfate
• Molecular Formula: K₂S₂O₈
• Molecular Weight: 270.31
• CAS Registry Number: 7727-21-1
• EC Number: 231-781-8
• SMILES: [O-]S(=O)(=O)OOS(=O)(=O)[O-].[K+].[K+]

Properties

• Density: 2.47
• Melting point: 100 °C
• Water solubility: 5 g/100 mL (20 °C)

Safety Data

• Hazard Symbols: GHS03;GHS08;GHS07 Danger
• Risk Statements: H272-H302-H335-H315-H319-H334-H317
• Safety Statements: P210-P220-P233-P260-P261-P264-P264+P265-P270-P271-P272-P280-P284-P301+P317-P302+P352-P304+P340-P305+P351+P338-P319-P321-P330-P332+P317-P333+P317-P337+P317-P342+P316-P362+P364-P370+P378-P403-P403+P233-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Respiratory sensitization	Resp. Sens.	1	H334
Acute toxicity	Acute Tox.	4	H302
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Oxidising solids	Ox. Sol.	3	H272
Skin sensitization	Skin Sens.	1	H317
Skin irritation	Skin Irrit.	2	H315
Oxidising solids	Ox. Sol.	2	H272
Skin sensitization	Skin Sens.	1B	H317
Chronic hazardous to the aquatic environment	Aquatic Chronic	2	H411
Eye irritation	Eye Irrit.	2A	H319
Oxidising liquids	Ox. Liq.	2	H272

• Transport Information: UN 1492

Discovery and Applications

Potassium persulfate (K₂S₂O₈) is a powerful oxidizing agent that has garnered attention since its discovery in the late 19th century. It was first synthesized by French chemists who were exploring the properties of sulfate compounds. Potassium persulfate appears as a white crystalline solid, highly soluble in water, and is stable under normal conditions, making it suitable for various applications.

The synthesis of potassium persulfate typically involves the reaction of potassium sulfate with concentrated sulfuric acid or through electrolysis of potassium sulfate solutions. This compound is notable for its ability to release sulfate radicals upon decomposition, making it a strong oxidizer.

Potassium persulfate is widely used in a variety of industrial and laboratory applications. One of its primary uses is as an initiator in the polymerization of monomers, such as acrylates and styrenes. The sulfate radicals generated from its thermal decomposition initiate the polymerization process, leading to the production of various plastics and synthetic fibers. This application is crucial in the manufacturing of materials such as polyacrylamide and polystyrene, which are used in countless everyday products.

In addition to polymerization, potassium persulfate is employed in analytical chemistry as a strong oxidizing agent for various reactions, including the determination of certain metals and organic compounds. Its ability to oxidize a wide range of substances makes it valuable in environmental testing and quality control processes in laboratories.

Moreover, potassium persulfate is utilized in the field of cosmetics and personal care products. It serves as a hair bleaching agent, where its oxidizing properties help in the removal of color from hair. Its application in this sector has contributed to the development of hair dyes and bleaching products that are popular among consumers seeking to change their hair color.

In the realm of water treatment, potassium persulfate is used as an oxidizing agent to remove contaminants from water supplies. It can break down organic pollutants and is particularly effective in the remediation of groundwater contaminated with solvents and other hazardous substances. This makes potassium persulfate an essential tool in environmental management and pollution control.

Despite its versatility, potassium persulfate must be handled with care due to its strong oxidizing properties. It can pose health risks if inhaled or if it comes into contact with skin or eyes. Proper safety precautions, including the use of personal protective equipment and adherence to handling guidelines, are crucial when working with this compound.

In conclusion, potassium persulfate is a valuable chemical compound with a wide range of applications in industries such as polymer production, analytical chemistry, cosmetics, and environmental management. Its discovery has paved the way for advancements in these fields, demonstrating its importance as a powerful oxidizing agent.

References

1987. The SOö·4-induced Chain Reaction of 1,3-dimethyluracil with Peroxodisulphate. International journal of radiation biology and related studies in physics, chemistry, and medicine, 51(1).
DOI: 10.1080/09553008714550931

2016. Methylene blue removal by submerged plasma irradiation system in the presence of persulfate. Environmental science and pollution research international, 23(15).
DOI: 10.1007/s11356-016-6759-1

2021. Enhanced activated persulfate oxidation of ciprofloxacin using a low-grade titanium ore under sunlight: influence of the irradiation source on its transformation products. Environmental science and pollution research international, 28(15).
DOI: 10.1007/s11356-020-11564-8