What Does CAS 7782-63-0 Mean? A Buyer’s Guide to Ferrous Sulphate Heptahydrate

The Universal Language of Chemical Identity

In the global chemical trade, commercial products go by hundreds of common, historical, and colloquial names. Ferrous sulphate has been referred to as copperas, green vitriol, iron vitriol, melanterite, and iron protosulfate. These historical labels carry ambiguity. To eliminate confusion, the American Chemical Society established the Chemical Abstracts Service (CAS) Registry, assigning a unique numerical identifier to every distinct chemical substance.

When sourcing Ferrous Sulphate Heptahydrate 98% Min, the non-negotiable benchmark is CAS 7782-63-0.

Distinguishing Heptahydrate from Other Iron Salts

Crucially, CAS numbers distinguish between different hydration states of the exact same ionic compound:

• CAS 7782-63-0: Iron(II) sulfate heptahydrate (FeSO₄·7H₂O) — pale green crystals, MW 278.01 g/mol, ~19.7% Fe.
• CAS 17375-41-6: Iron(II) sulfate monohydrate (FeSO₄·H₂O) — off-white powder, MW 169.93 g/mol, ~30.0% Fe.
• CAS 7720-78-7: Anhydrous iron(II) sulfate (FeSO₄) — white hygroscopic powder, MW 151.91 g/mol, ~36.7% Fe.
• CAS 10028-22-5: Ferric sulfate (Fe₂(SO₄)₃) — trivalent iron salt, distinct chemical behaviour.

Specifying 'CAS 7782-63-0' in purchase orders and contracts legally binds the supplier to deliver the heptahydrate form with seven crystal waters, preventing accidental delivery of anhydrous or dried powder.

Customs and Regulatory Compliance in Kenya

For shipments arriving through the Port of Mombasa, the Kenya Revenue Authority (KRA) and Kenya Bureau of Standards (KEBS) require unambiguous chemical declarations on the Import Declaration Form (IDF) and Pre-Export Verification of Conformity (PVoC). Declaring CAS 7782-63-0 verifies the correct HS Code classification (2833.29) and speeds clearance through the National Electronic Single Window System.

Safety Data Sheets and Hazard Communication

Under the Globally Harmonized System (GHS) enforced across East African industrial safety frameworks, Section 1 and Section 3 of every Safety Data Sheet (SDS) must display the CAS number. Plant safety officers in Nairobi and Mombasa rely on CAS 7782-63-0 to cross-reference toxicological data, exposure limits, and spill containment protocols in chemical registers.

Verify incoming chemical specification documents: How to Read a Ferrous Sulphate COA Before Buying.

Explore multi-industry applications: Industrial Ferrous Sulphate Applications Beyond Water Treatment.