Date: 21 August 2026
Prepared for: Importers, Manufacturers, Suppliers and Buyers of Cosmetic Products for the Great Britain Market
Regulatory Update: UK Cosmetic Substance Bans Take Effect - 4-MBC, 16 CMR and Formaldehyde Labelling
On 12 January 2026, the UK Government made The Cosmetic Products Regulation (EC) No 1223/2009 (Restriction of Chemical Substances) (Amendment and Transitional Provisions) Regulations 2026 (SI 2026/23) . While the statutory instrument was made in January, its provisions have been phased in over two effective dates — both of which are now in force as of 15 August 2026.
Background:
The amendments follow advice from the Scientific Advisory Group on Chemical Safety of Non-Food and Non-Medicinal Consumer Products (SAG-CS), which identified potential health risks associated with certain substances used in cosmetic products.
The changes also reflect the UK Health and Safety Executive's classification of 16 substances as CMR (carcinogenic, mutagenic or toxic for reproduction) under the UK CLP Regulation. The regulation has therefore been updated to introduce new substance prohibitions, updated labelling requirements and transitional arrangements for cosmetic products placed on the Great Britain market (England, Scotland and Wales).
Timeline:
Ingredient | Effective date | Status |
Ban on 4-MBC (Enzacamene) (CAS 36861-47-9) | 15 July 2026 | Phase 1 |
Lowered formaldehyde releasing preservative labelling threshold | 15 July 2026 | Phase 1 |
Prohibition of 16 newly classified CMR substances | 15 August 2026 | Phase 2 |
Phase 1 – Changes Effective from 15 July 2026
1. Prohibition of 3-(4′-methylbenzylidene)-camphor (Enzacamene / 4-MBC)
From 15 July 2026, the regulations amend Annex II (prohibited substances) to prohibit the use of 3-(4′-methylbenzylidene)-camphor (enzacamene; CAS No. 36861-47-9) . The substance is also removed from Annex VI (UV filters) at the same time.
2. Formaldehyde-Releasing Preservatives – Lowered Labelling Threshold
From 15 July 2026, the preamble to Annex V (preservatives) is amended, tightening warning labelling for formaldehyde-releasing preservatives:
Aspect | Previous Requirement | New Requirement |
Wording | "contain" formaldehyde | "release" formaldehyde |
Threshold triggering warning | 0.05% (500 ppm) | 0.001% (10 ppm) |
Products containing preservatives listed in Annex V must now carry the warning "releases formaldehyde" where the concentration of formaldehyde released by the finished product exceeds 0.001% (10 ppm).
Common formaldehyde-releasing preservatives covered by this requirement include:
l DMDM hydantoin (CAS 6440-58-0)
l Imidazolidinyl urea (CAS 39236-46-9)
l Diazolidinyl urea (CAS 78491-02-8)
l Quaternium-15 (CAS 4080-31-3 / 51229-78-8)
l Sodium hydroxymethylglycinate (CAS 70161-44-3)
l Bronopol (CAS 52-51-7)
l Methenamine (CAS 100-97-0)
Phase 2 – Prohibition of 16 Newly Classified CMR Substances Effective from 15 August 2026
From 15 August 2026, further amendments to Annex II prohibit 16 additional substances classified as CMR category 1B or 2 under the UK CLP Regulation. These substances are listed in the Schedule to SI 2026/23:
Annex II Ref. | Substance Name | CAS No. |
1745 | Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide | 75980-60-8 |
1746 | Clothianidin (ISO) | 210880-92-5 |
1747 | Dimethyl propylphosphonate | 18755-43-6 |
1748 | Dibutyltin maleate | 78-04-6 |
1749 | Dibutyltin oxide | 818-08-6 |
1750 | 2,2′,6,6′-tetrabromo-4,4′-isopropylidenediphenol (tetrabromobisphenol A) | 79-94-7 |
1751 | 1,4-Benzenediamine, N,N′-mixed phenyl and tolyl derivatives | 68953-84-4 |
1752 | 4-Methylimidazole | 822-36-6 |
1753 | Acetone oxime | 127-06-0 |
1754 | Benthiavalicarb isopropyl (ISO) | 177406-68-7 |
1755 | 2,3-Epoxypropyl neodecanoate | 26761-45-5 |
1756 | Multi walled carbon nanotubes | — |
1757 | 7-Oxabicyclo[4.1.0]hept-3-ylmethyl 7-oxabicyclo[4.1.0]heptane-3-carboxylate | 2386-87-0 |
1758 | 2-(Dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(morpholin-4-yl)phenyl]butan-1-one | 119344-86-4 |
Transitional Arrangements
l Cosmetic products placed on the market before 15 July 2026 that contain 4-MBC and are labelled in accordance with previous Annex V requirements may continue to be made available until 14 January 2027.
l Cosmetic products placed on the market before 15 August 2026 that contain any of the newly prohibited CMR substances may continue to be made available until 14 February 2027.
What this means for you
Now that both phases are fully in force, if you supply cosmetic products to Great Britain, three actions are particularly relevant:
l Verify that your formulations do not contain 4-MBC. The ban is effective from 15 July 2026. Existing stock labelled under the old rules may be sold through until 14 January 2027.
l Review your labels for formaldehyde-releasing preservatives. The new 0.001% (10ppm) threshold applies from 15 July 2026 with no transitional period – labels must now carry "releases formaldehyde" where triggered.
l Screen your formulations against the 16 newly prohibited CMR substances. These are prohibited from 15 August 2026, with existing stock permitted until 14 February 2027.
Key point to understand:
These changes stem from a single statutory instrument (SI 2026/23) with two distinct effective dates. The 4-MBC ban and formaldehyde labelling changes took effect on 15 July 2026, while the 16 CMR substance prohibitions took effect on 15 August 2026. Each set of requirements has its own transitional sell-through period – 14 January 2027 for 4-MBC and 14 February 2027 for the CMR substances.
For further information, the full text of SI 2026/23 is available on the UK legislation website. Should you require support with regulatory compliance for the Great Britain market, please do not hesitate to contact us.
Reference: SI 2026/23 - The Cosmetic Products Regulation (EC) No 1223/2009 (Restriction of Chemical Substances) (Amendment and Transitional Provisions) Regulations 2026
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