European Community number

The European Community number (EC Number) is a unique seven-digit identifier that was assigned to substances for regulatory purposes within the European Union by the European Commission. The so-called EC Inventory comprises three individual inventories, EINECS, ELINCS and the NLP list.

Structure

The EC Number may be written in a general form as: NNN-NNN-R, where R is a check digit and N represents integers. The check digit is calculated using the ISBN method. According to this method, the check digit R is the following sum modulo 11:

If the remainder R is equal to 10, that combination of digits is not used for an EC number. To illustrate, the EC number of dexamethasone is 200-003-9. N₁ is 2, N₂ through N₅ are 0, and N₆ is 3.

The remainder is 9, which is the check digit.

There is a set of 181 ELINCS numbers (EC numbers starting with 4) for which the checksum by the above algorithm is 10 and the number has not been skipped but issued with a checksum of 1.

EC Inventory