EU CLP Revision 2026: New Hazard Classes for Endocrine Disruptors and PBT Substances

What new hazard class has been added for endocrine‑disrupting chemicals under the 2026 CLP revision?

The 2026 amendment creates a distinct hazard class titled “Endocrine Disruptor (ED)” within the existing “Specific Target Organ Toxicity – Repeated Exposure (STOT‑RE)” category. Substances that meet the EU criteria for endocrine disruption – demonstrated by adverse effects on the endocrine system at relevant exposure levels – must now be labelled with the pictogram for a specific target organ toxicity and the phrase “May cause endocrine disruption”.

Key points:

• The classification is triggered when a substance shows adverse effects on the endocrine system in at least one of the three modes (estrogen, androgen, thyroid, or steroidogenesis) at concentrations ≤ 1 µg kg⁻¹ (for solids) or ≤ 1 µg L⁻¹ (for liquids) in the relevant test system.
• Data requirements include in vitro assays (e.g., OECD TG 458, 456) and, where necessary, in vivo follow‑up (OECD TG 443).
• Existing REACH‑registered substances will be re‑evaluated under the new criteria, with a two‑year transition period for compliance.

The introduction of a dedicated class aims to improve downstream risk communication and to harmonise labelling with the EU’s broader strategy on endocrine disruptors, as outlined in the recent European Commission communication on chemicals and health [1].

How does the revised CLP regulation address Persistent, Bioaccumulative and Toxic (PBT) substances?

The 2026 revision expands the PBT criteria by introducing a new sub‑category “PBT‑v” for substances that are very persistent (half‑life > 100 days in water, > 180 days in soil) and very bioaccumulative (bioaccumulation factor > 5000). These substances must be labelled with the standard PBT pictogram plus the phrase “Very persistent, very bioaccumulative and toxic”.

Specific changes include:

• Lowered persistence thresholds for water (from 60 days to 30 days) and soil (from 120 days to 90 days) for the standard PBT class, reflecting newer environmental monitoring data.
• Mandatory inclusion of chronic toxicity data for aquatic organisms (e.g., EC50/LC50 ≤ 0.01 mg L⁻¹) and for mammals (NOAEL ≤ 0.1 mg kg⁻¹ day⁻¹) when classifying a substance as PBT.
• Harmonised labelling across the EU, with a requirement that safety data sheets (SDS) display the PBT classification on the first page and include a risk management advice section.

These adjustments align CLP with the REACH Annex VIII amendments that entered force in 2025, ensuring that substances identified as PBT‑v under REACH are automatically classified under CLP without additional testing [2].

What are the compliance timelines and reporting obligations for manufacturers and importers?

The EU Commission has set a phased implementation schedule:

1. January 2026 – Publication of the revised CLP annexes in the Official Journal of the EU.
2. July 2026 – Mandatory labelling for newly placed substances that meet the ED or PBT‑v criteria.
3. January 2027 – Deadline for existing substances on the market to be re‑classified and relabelled, provided that the required data are available.
4. December 2027 – Final deadline for submission of updated Classification and Labelling (C&L) notifications to the European Chemicals Agency (ECHA).

Manufacturers must submit a new C&L notification via the ECHA IUCLID system, attaching the relevant CoA, SDS, and any supporting in vitro/in vivo study reports. Failure to update the classification by the 2027 deadline may result in penalties up to €150 000 per violation and possible market withdrawal.

How will the new classes affect risk assessment and product development?

The introduction of explicit ED and PBT‑v classes forces a more granular hazard identification step early in the product development pipeline. Companies typically need to:

• Conduct screening assays for endocrine activity during the lead‑optimization phase, reducing the risk of later re‑classification.
• Incorporate persistence and bioaccumulation modelling (e.g., using OECD QSAR Toolbox) to predict whether a candidate will fall under the stricter PBT‑v thresholds.
• Update internal SOPs for SDS preparation to ensure the new phrasing and pictograms are automatically populated.

From a risk‑management perspective, the new classes enable downstream users – such as pharmaceutical manufacturers – to plan substitution strategies more effectively, as the labelling now conveys a clearer signal of long‑term environmental and health concerns.

What role does Molekula play in supporting compliance with the 2026 CLP changes?

Molekula provides regulatory‑grade documentation (updated SDS, CoA, and REACH registration dossiers) that incorporate the revised CLP classifications. By offering validated analytical data (e.g., HPLC‑MS, GC‑MS) and in‑house endocrine‑disruption screening, the company helps customers meet the new data requirements without extensive external testing. This support is particularly valuable for small‑to‑medium enterprises that lack dedicated regulatory teams.

Frequently asked questions

Q1: Do existing products need to be relabelled immediately? A: No. Existing products placed on the market before 2026 have a grace period until January 2027 to update their labelling, provided the necessary data are available.

Q2: Are there exemptions for substances used in closed systems? A: The CLP revision does not provide blanket exemptions for closed‑system use. However, if exposure is demonstrably negligible, a risk‑based justification can be submitted to ECHA.

Q3: How are mixtures handled under the new ED class? A: A mixture is classified as an endocrine disruptor if any component meets the ED criteria at the relevant concentration in the final formulation.

Q4: What testing methods are accepted for confirming PBT‑v status? A: Accepted methods include OECD TG 307/308 for persistence, TG 305 for bioaccumulation, and chronic toxicity tests such as TG 210 (fish) and TG 229 (rodents).