Big Changes in EU Hazard Classification 

Suppliers placing substances on the EU market need to comply with new classification rules as of May 1st, 2025, while for mixtures this will be May 1st, 2026

With the European Union’s Green Deal and Chemicals Strategy for Sustainability the EU has set a goal to better protect human health and the environment. As part of this strategy the European Commission has introduced new hazard classes for endocrine disruptors as well as for chemicals that do not break down in the environment and that have a high potential to bioaccumulate in living organisms or spread across the water cycle, including drinking water. With deadlines coming up quicker than initially anticipated, companies are currently under pressure to evaluate their substances and determine whether classification in any of the new hazard classes is needed.

What is Endocrine disruption?

The endocrine system is a complex network of glands and organs communicating through hormones and receptors providing a control link between the nervous system and important bodily functions such as growth and development, immunity, metabolism and reproduction. Endocrine disruptors (ED) are substances that have an endocrine activity and can disrupt endocrine function leading to an adverse effect in human and wildlife alike Exposure of humans and the environment is increasingly linked to endocrine-related disorders including neurological disorders and cancer.

The regulatory systems in the EU are being updated to ensure that endocrine disruptors are being recognized in a timely manner and exposure of humans and the environment is minimized. However, identifying substances with endocrine-disrupting potential is a significant challenge.

Endocrine Disruptor Classification 

The hazard classes for endocrine disruptors for both human health and the environment include two categories, namely ‘known or presumed’ (Cat. 1) and ‘suspected’ (Cat. 2). Substances classified as ED would satisfy the following three criteria:

1. Present an endocrine activity
2. Have an adverse effect on an intact organism or its offspring and future generations
3. Have a biologically plausible link identified between the endocrine activity and the adverse effect

The hazard classification should be based on a “weight of evidence” determination using all available data. At the end of 2024, the European Chemicals Agency published guidance on how to apply the classification criteria. Although this guidance is a first step there are still issues that require future attention such as population relevance and considerations on thyroid-mediated endocrine disruption. A version 2.0 of the guidance is already anticipated once practical experience is gained.

Currently there is only limited information available on the large number of substances on the market in the EU regarding their ED potential. Depending on their production tonnage level there may be data on adversity. However, there is often little to no data on endocrine activity. While the so-called Classification, Labeling and Packaging (CLP) regulation sets out the hazard classes and criteria for classification, it does not set information requirements or require further testing of substances for classification purposes. The information requirements for substances are part of the so-called REACH regulation. The European Commission has been planning a REACH revision proposal to introduce new data requirements to address potential concerns for ED. However, this has been delayed.

Currently a proposal for amendments of the annexes of the REACH regulation with additional information requirements providing information on endocrine disruption are expected by the end of 2025.  

Persistent substances of concern 

Substances that possess persistent, bioaccumulative and toxic (PBT) and/or very persistent, very bioaccumulative (vPvB) properties persist for long periods of time in the environment and have a high potential to accumulate in biota making their long-term effects unpredictable and exposure to the environment difficult to reverse.

In recent years, substances that possess persistent, mobile and toxic (PMT) and/or very persistent, very mobile (vPvM) properties have received increased scientific and regulatory attention. These substances breakdown slowly in the environment and have a high environmental mobility often reaching (drinking) water resources. Substances with PMT/vPvM properties are only partly removed by wastewater and drinking water treatment processes and can potentially spread causing environmental exposures that are difficult to reverse.

PBT/vPvB, PMT/vPvM classifications explained

The hazard classes of PBT and vPvB properties follow the existing criteria as set out in Annex XIII of REACH, but for PBT now include additional criteria for toxicity based on an ED classification (Cat.1) for humans or the environment. The hazard classification for PMT and vPvM were added as the combination of these properties (very persistent and very mobile or persistent, mobile and toxicity) can pose a threat to drinking water sources. A substance is considered mobile if it possesses moderate to (very) low adsorption potential.

The Guidance on Information Requirements and Chemical Safety Assessment has been updated and provides the first point of reference when evaluating PBT properties also under CLP. The updated ECHA guidance on CLP published end of 2024 now specifies the approach for classification, including for the aspect mobility (M). 

No time to waste

The new hazard classes have entered into force as of April 2023. However, to ensure that suppliers of substances and mixtures have time to adapt, the old classification rules can be applied until May 1, 2025 (substances) or May 1, 2026 (mixtures). During this phase manufacturers, importers, downstream users and distributors are not yet required to classify their substance or mixtures but can apply the hazard classes on a voluntary basis.

Quantities of substance or mixtures already on the market do not have to be re-classified or re-labelled November 1, 2026, or May 1, 2028, respectively. Clarification on the application timelines by the EU commission has made clear that new quantities of substances placed on the market after May 1, 2025, must be classified and labelled in accordance with the new hazard classes. The same applies to mixtures as of May 1, 2026.

The assessments needed to determine the appropriate classification require a considerable time investment, especially for data-rich substances, and expertise. Initial unclarity on the transition periods in the timelines and the wait for the guidance on the application of the hazard classes in combination with the integrated assessment that is needed to determine appropriate classification makes that companies are now under pressure to evaluate their substances in time.

What to expect from these regulatory changes?

Currently, ~100 substances are identified under the REACH Candidate List as having endocrine disruptor, PBT/vPvB and/or PMT/vPvM properties but this could increase dramatically based on the impact assessment¹ where a minimum of 1,650 substances is estimated to warrant classification. Substances classified for ED, PBT/vPvB or PMT/vPvM can be identified as substances of very high concern when they meet the “equivalent level of concern” criteria set out in Article 57(f) of REACH.

In this complex and constantly evolving regulatory landscape, our CRL experts at Regulatory Affairs stay up to date with the latest developments concerning endocrine disruption, PBT and PMT assessments. With many years of experience dealing with these assessments and related testing CRL can assist with registration strategies and classification of substances and mixtures.  

Reference:
1. Commission non-paper, “Impact assessment for the revision of the CLP Regulation”, p. 3.