Research reagent 2046B

laboratoryfor histopathologyfor the medical sector

Short description
Potassium alum (rock alum) (KAl(SO₄)₂·12H₂O, CAS 7784-24-9) is a white crystalline solid, astringent and mordant, soluble in water. Supplied as a raw material with a dry-basis assay of 97–99% together with Technical Data Sheet, SDS (REACH/CLP) and Certificate of Analysis for each batch.

Physico-chemical properties
Parameter: Value
Name: Potassium alum (potassium aluminium sulfate)
CAS number: 7784-24-9
EC number: 233-141-3
Synonyms: rock alum, potassium alum, potassium aluminum sulfate dodecahydrate
Molecular formula: KAl(SO₄)₂·12H₂O
Appearance: crystals
Colour: white
Odour: odourless
Solubility: soluble in water
Class: hydrated double sulfate (inorganic salt)

Product specifications
Parameter: Specification
Appearance: white odourless crystals
Assay (dry basis): 97 – 99 %
Water (30 minutes at 45 °C): max. 3 %

What is rock alum used for
Potassium alum is used as a mordant in dyeing and the textile industry to fix dyes on natural fibres. In leather tanning it is a traditional tanning agent (alum tanning). In water treatment it acts as a coagulant for clarification. In histological diagnostics it is a component of aluminium haematoxylin (e.g. Mayer, Harris) for staining cell nuclei. In cosmetics and personal hygiene it is the active ingredient of crystal deodorants.

Product features
Potassium alum is supplied as white crystals with a controlled water content and a dry-basis assay of 97–99%, suitable for technical, dyeing and diagnostic applications where reproducibility is important. Technical Data Sheet, Safety Data Sheet (SDS) and Certificate of Analysis (CoA) are provided for each batch.

Areas of application

• Textile: mordant in dyeing of natural fibres
• Leather: tanning agent (alum tanning)
• Water treatment: coagulant for clarification
• Histological diagnostics: component of aluminium haematoxylin (Mayer, Harris)
• Laboratory: chemical and analytical reagent
• Cosmetics: natural deodorant (alum crystal)

CLP classification and safety
Not classified as hazardous under Regulation (EC) 1272/2008 under normal conditions of use. Standard precautions are required during handling. SDS provided with each supply.

Compliance and documentation
Product is managed in compliance with REACH and CLP regulations. Technical documentation (TDS, SDS, CoA) is issued for each batch.

Customisation and contract manufacturing
Customised supplies and contract packaging can be evaluated for dedicated formats and batches with specific CoA and technical support.

Frequently Asked Questions (FAQ)
What is rock alum? It is the double salt of potassium and aluminium (KAl(SO₄)₂·12H₂O, CAS 7784-24-9): white odourless crystals with a dry-basis assay of 97–99%, soluble in water.
What is the difference between rock alum and potassium alum? They are the same compound: “rock alum” is the common commercial name, “potassium alum” the systematic chemical name.
Can it be used in histological diagnostics? Yes. It is a key component of aluminium haematoxylin (Mayer, Harris) for basophilic staining of nuclei in histological sections.

Caractéristiques / spécifications techniques

• Name: Potassium alum (Potassium aluminium sulfate)
• Denomination / commercial name: Potassium alum (rock alum)
• CAS number: 7784-24-9
• EC number: 233-141-3
• Chemical formula: KAl(SO₄)₂·12H₂O
• Appearance: white crystals
• Assay (dry basis): 97–99 %
• Water (30 minutes at 45 °C): max. 3 %
• Solubility: soluble in water
• Typical supplied weight (single product listing): 1.2 kg (product attribute)
• Available packaging/size options (as product variations): Sacco, Barattolo
• Documentation supplied per batch: Technical Data Sheet, SDS (REACH/CLP), Certificate of Analysis