The 23rd Adaptation to Technical and Scientific Progress (23rd ATP) to Regulation (EC) No 1272/2008 (CLP) was published in the Official Journal of the European Union on 20 June 2025.

The official title of the act is:

Commission Delegated Regulation (EU) 2025/1222 of 2 April 2025 amending Regulation (EC) No 1272/2008 of the European Parliament and of the Council as regards the harmonised classification and labelling of certain substances.

This amendment introduces changes to the classification and labelling of several already harmonised substances and adds new harmonised classifications to Part 3 of Annex VI of the CLP Regulation.

Quick overview in numbers

  • 22 new entries with assigned index numbers
  • 10 existing entries replaced with updated classifications

The 23rd ATP shall apply from 1 February 2027.


Overview of Selected Changes

Below is a brief overview of some of the more commonly encountered substances affected by this ATP.


New Harmonised Substances

Substance nameIdentifiersClassificationIndex No.
2-ethylhexanoic acid, monoester with propane-1,2-diolCAS: 85114-00-7
EC: 285-503-5
H360D607-776-00-5
N-1-naphthylaniline; N-phenylnaphthalen-1-amineCAS: 90-30-2
EC: 201-983-0
H302
H373 (blood system, liver)
H317
612-300-00-4
Tetrairon tris(pyrophosphate); iron pyrophosphateCAS: 10058-44-3
EC: 233-190-0
H319026-005-00-8
Dinitrogen oxideCAS: 10024-97-2
EC: 233-032-0
H360Df
H336
H372 (nervous system)
H420
007-031-00-9

Updated Harmonised Entries

Substance nameIdentifiersClassificationIndex No.
2-Phenylpropene; α-MethylstyreneCAS: 98-83-9
EC: 202-705-0
H226
H335
H317
H319
H351
H411
601-027-00-6
3-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate; Isophorone diisocyanateCAS: 4098-71-9
EC: 223-861-6
H330
H314
H317
H318
H334
H411
615-008-00-5
3-Iodo-2-propynyl butylcarbamate; 3-Iodoprop-2-yn-1-yl butylcarbamateCAS: 55406-53-6
EC: 259-627-5
H330
H302
H317
H318
H372 (larynx)
H400
H410
616-212-00-7

Early Application Possibility

Although the mandatory application date is 1 February 2027, suppliers of substances and mixtures may already classify, label, and package according to this amendment from the date of its entry into force, which is 10 July 2025.

This allows companies to align their documentation and labelling earlier and reduce transition pressure closer to the enforcement deadline.


How Chemius Supports Your CLP Compliance

Managing ATP updates across Safety Data Sheets, classifications, labels, and internal systems can quickly become resource-intensive—especially when multiple substances and markets are involved.

Chemius helps by:

  • Monitoring ATP updates and mapping them to your substance portfolio
  • Identifying affected substances, mixtures, and downstream documents with the help of Regulatory dashboard
  • Supporting timely SDS updates aligned with the new harmonised classifications
  • Maintaining consistency across regulatory, sales, and supply chain documentation
  • Providing one central place where updates are tracked, implemented, and accessible across teams

This approach reduces manual checks, version mismatches, and last-minute corrections as regulatory deadlines approach.


If you need support interpreting the 23rd ATP or understanding how it affects your products, classifications, or documentation, our team is available to assist. Note that we can charge 180 euros for consultancy hour.

📩 Contact us at:
support@chemius.net

Early alignment today saves time, cost, and internal pressure tomorrow.


Disclaimer

Information published in this blog is prepared with the utmost care. However, it does not constitute chemical consulting, and no responsibility or liability is assumed for the correctness, accuracy, or timeliness of the content. For advice related to a specific case, please contact us at support@chemius.net

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