To develop a valid notification for the Health and Safety Executive (HSE), you must include: : Details of the manufacturer or importer. Substance Data : Substance name, CAS number, or EC number.

A DUIN is a temporary measure that allows Great Britain-based companies to continue importing substances from the EU/EEA after Brexit without an immediate full registration.

: You can submit a DUIN if you were a downstream user or distributor under EU REACH before January 1, 2021.