Great Britain Proposes New Entries for the GB MCL List: Classification and Labelling of 30 Hazardous Chemicals

The United Kingdom has notified the World Trade Organization (WTO) of a draft regulation proposing the addition of 30 substances to the GB Mandatory Classification and Labelling (GB MCL) List. This is one of a series of ongoing updates to the UK’s independent chemicals framework following Brexit and is aligned with the GB Classification, Labelling and Packaging (CLP) Regulation, which applies in England, Scotland, and Wales.

The GB MCL list is updated regularly to reflect scientific developments and protect human health and the environment. This update marks another step in Great Britain’s regulatory divergence from the EU’s CLP system since the end of the Brexit transition period.

Key Substances and Hazards

The proposal covers substances posing serious risks to human health and the environment, including:

• Carcinogens: e.g. 1,4-dichloro-2-nitrobenzene (Carc. 1B)

• Reproductive toxins: e.g. sodium perborate and glycerol formal (Repr. 1B)

• Aquatic hazards: e.g. copper, pyraclostrobin

• Mutagens and sensitizers: e.g. N,N'-methylenediacrylamide (Muta. 1B), several fragrance substances (Skin Sens. 1)

• Other hazards, including causing serious eye damage, having specific target organ toxicity (STOT), and being flammable.

The classifications are based on scientific evaluations by the UK Health and Safety Executive (HSE).

Implications for Industry

Manufacturers, importers, and downstream users will be required to update hazard labelling and safety data sheets, and potentially reformulate products in order to comply with the proposed classifications.

Consultation Details

The proposal was notified to the World Trade Organization under reference G/TBT/N/GBR/101. Stakeholders are invited to submit comments on the draft regulation by 6 June 2025. The full text of the proposed measure, including the list of substances and their classifications, is available in the notified document, which can be accessed here.