News Details

On 26 January 2026, the UK Health and Safety Executive (HSE) notified the World Trade Organization (WTO) of a proposal to amend Great Britain’s mandatory classification and labelling (GB MCL) list by introducing new and revised entries for 60 hazardous chemical substances.

According to the notification, this follows a regulatory review and aims to protect human health and safety, protect the environment, and ensure the proper functioning of the UK internal market.

The proposal is made under the GB CLP Regulation, which is the assimilated version of Regulation (EC) No 1272/2008 as retained and amended for Great Britain following EU exit.

Examples of Substances Proposed for Listing

The notified document sets out the mandatory classifications and labelling elements for the 60 substances, including the hazard classes, hazard statements and pictograms/signal words. Examples in the list include:

• Reproductive toxicity (Repr. 1B) entries such as:
  • Undecafluorohexanoic acid (PFHxA) and its salts (Repr. 1B, H360D), including sodium and ammonium salts.
  • A range of boron compounds (metaborates, tetraborates, pentaborates, decaborates) (Repr. 1B, H360FD), with a note that mixture classification is required where the sum of the relevant boron compounds is ≥ 0.3%.
  • Several bromide salts (for example sodium, calcium, potassium bromide) with Repr. 1B classification and additional notes on mixture classification triggers (including a ≥ 0.3% threshold based on the sum of relevant bromide salts).
• Carcinogenicity and mutagenicity entries, including:
  • Fluoroethylene (Muta. 2; Carc. 1A, H350).
  • Trimethyl phosphate (Carc. 1B; Muta. 1B; Repr. 1B; plus acute and repeated exposure toxicity statements).
• Respiratory sensitisers and acute toxicity entries, including:
  • Isophorone diisocyanate with acute inhalation toxicity and respiratory sensitisation, plus specific concentration limits for sensitisation (for example, H334 at C ≥ 0.5% and H317 at C ≥ 0.001%).
• Pesticide active substances and biocides, including entries for substances such as folpet, captan, clopyralid, dinotefuran, proquinazid, pyriproxyfen, penconazole, and others. These often have aquatic hazard classifications and associated M-factors where applicable.
• Multiple copper compounds (for example copper oxides, hydroxides, carbonates, sulphates, Bordeaux mixture), frequently classified for aquatic acute/chronic hazards, and in some cases acute toxicity and serious eye damage.

The full list of substances and their proposed mandatory classifications is set out in the notified document, which is available here.

Consultation timeline and next steps

Stakeholders may submit comments on the proposal until 27 March 2026, which is the end of the 60-day WTO consultation period.

The United Kingdom expects the measure to be adopted in Q2 2026, with voluntary application from Q2 2026 and mandatory application from Q4 2028.