European Community number

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.

European Chemicals Agency (ECHA) also applies the EC number format to what it calls "List number".

[6] The number are assigned under the REACH Regulation without being legally recognised.

List numbers are administrative tools only and shall not be used for any official purposes.