REACH Authorisation numbers
REACH authorisation numbers cannot be used to identify specific chemical substances, and are not valid for identifying chemical substances in CLP and on the Safety Data Sheet.
However, Authorisation numbers are required to be placed on the CLP label and the Safety Data Sheet for any Authorised substance, in addition to the normal chemical identification numbers (EC, CAS, Index number).
Authorisation occurs under REACH and there is information on the process at https://ttenvironmenta.wpengine.com/clp-knowledgebase/svhc-list/ .
Once a substance has been Authorised, it can only be used or sold by companies with a valid Authorisation (which costs money).
The Authorisation number takes the format REACH/xx/xx/x .