After the Brexit, the UK developed its own Chemical Classification, Labelling and Packaging (CLP) regulation based on the EU CLP Regulation. Additionally, the UK established the Chemical Mandatory Classification and Labelling Inventory (GB MCL). This inventory is applicable in the Great Britain and retains the harmonized classification and labelling standards (CLH) updated by the EU before December 31, 2020. From January 1, 2021, chemicals or mixtures placed on the GB market must comply with the requirements of the GB CLP regulations. If a new substance is placed on the market and does not meet the exemption criteria, then relevant GB manufacturers, importers, and suppliers from the Northern Ireland which place new substances to the GB are required to notify to the Health and Safety Executive (HSE) within one month.