Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

Build a label

Substance profile

Potassium hydrogensulphate

Potassium hydrogensulphate: large Crystals; Other Solid; Dry Powder; Large Crystals.

CAS 7646-93-7 HKO4S 136.17 g/mol Danger

01 · Identification

What Potassium hydrogensulphate is

Potassium hydrogensulphate: large Crystals; Other Solid; Dry Powder; Large Crystals. Its molecular formula is HKO4S and its molecular weight is 136.17 g/mol.

Under the GHS it carries the signal word Danger. It is classed as corrosives.

CAS number7646-93-7
EC number231-594-1
Index number016-056-00-4
Molecular formulaHKO4S
Molecular weight136.17 g/mol
Chemical class Corrosives

02 · GHS classification

Hazards and label elements

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

Signal wordDanger
Hazard statements assigned to Potassium hydrogensulphate
CodeHazard statement
H335 May cause respiratory irritation.
H314 Causes severe skin burns and eye damage.

Precautionary statements: P260, P280, P301, P310, P331

03 · Physical and chemical properties

Potassium hydrogensulphate properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

Property Value Conditions Source
Density 2.2 g/cm³ ICSC
2.24 g/cm³ at 25 °C DOE PAC
Solubility Solubility in water, g/100ml: 49 (very good) ICSC
Freely soluble in water, insoluble in ethanol EU Food Improvement Agents

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

04 · Handling and storage

Storing and handling Potassium hydrogensulphate

Reactivity

Acidic salts, such as POTASSIUM HYDROGEN SULFATE, are generally soluble in water. The resulting solutions contain moderate concentrations of hydrogen ions and have pH's of less than 7.0. They react as acids to neutralize bases. These neutralizations generate heat, but less or far less than is generated by neutralization of inorganic acids, inorganic oxoacids, and carboxylic acid. They usually do not react as either oxidizing agents or reducing agents but such behavior is not impossible. Many of these compounds catalyze organic reactions.

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check Potassium hydrogensulphat… in the storage compatibility matrix →

Get the free GHS / CLP / OSHA deadline calendar

Verified 2026–2029 compliance dates in one PDF — plus alerts when the rules change.