ConceptsDefined term

EC Number

Note: general educational information, not legal advice. Check the official source before relying on it.

A seven-digit identifier in the format NNN-NNN-N assigned to substances in the European inventory, used alongside the CAS number.

Updated
2026-06-12

Definition#

An EC number is a seven-digit identifier in the format NNN-NNN-N assigned to substances in the European inventory. The inventory draws on lists such as EINECS and ELINCS, and the final digit is a check digit.

Format
Seven digits, NNN-NNN-N
Source
European inventory, including EINECS and ELINCS
Used with
The CAS number, in REACH and CLP

The EC number sits alongside the CAS number as a way to identify a substance in EU chemicals law. Having both gives a clear, language-independent reference when substances are declared.

Check an EC number#

The last digit is a check digit, computed from the first six. Enter an EC number to validate it and see the calculation.

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EC NumberEC NumberSubstance (REACH)SubstanceCAS NumberCAS NumberREACH: Registration, Evaluation, Authorisation and Restriction of ChemicalsREACHCLP: Classification, Labelling and Packaging Regulation (1272/2008)CLP
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