Navigating CLP Hazard Class Updates under REACH

Feb 5

Strategic Implications for REACH Lead Registrants in the Chemical Industry

The European Commission has introduced new hazard classes into the CLP Regulation, including categories such as endocrine disruption, persistent, bioaccumulative and toxic (PBT), very persistent and very bioaccumulative (vPvB), persistent, mobile and toxic (PMT), and very persistent and very mobile (vPvM) substances. These changes represent a significant update to chemical hazard assessment and labelling obligations for manufacturers, importers, and downstream users.

Despite its focus on CLP, the new Regulation (Commission Delegated Regulation (EU) 2023/707) has far-reaching implications for REACH compliance, particularly for lead registrants. Any change in self-classification triggered by the new hazard classes triggers obligations under REACH Article 22 and Commission Implementing Regulation (EU) 2020/1435, requiring registration dossiers to be updated within six months of the registrant’s decision on classification. These timelines apply regardless of the transitional periods provided under CLP.

For lead registrants overseeing complex substance groups, multi-entity registrations, or global supply chains, this may represent a major challenge. Coordinating scientific assessment, discussions with co-registrants, dossier updates, and Chemical Safety Report (CSR) revisions within compressed timeframes will require structured governance and early action.

Regulatory Background: CLP and REACH Interactions

Delegated Regulation (EU) 2023/707 expands the CLP framework by introducing new hazard classes and criteria, including those relating to endocrine disruption, persistence, bioaccumulation, and mobility. These additions require manufacturers and importers to reassess substances already on the EU market and determine whether re-classification is required.

Although CLP governs hazard communication through labels and safety data sheets, its influence has direct ramifications for REACH compliance. REACH Article 22 obliges registrants to keep their registration dossiers “up to date without undue delay” following any change that affects the information submitted, including classification and labelling. Article 6 of Commission Implementing Regulation (EU) 2020/1435 further clarifies that changes to classification must be submitted within six months of the registrant’s decision to change the classification.

This requirement applies whether the change arises from new data, revised scientific interpretation, or regulatory developments such as the new CLP hazard classes.

CLP allows transitional periods for applying the new hazard classes. For substances already placed on the EU market before 1 May 2025, companies may continue to use existing classifications until 1 November 2026.

It is important to note that the CLP transitional periods do not suspend REACH obligations. Once a registrant decides that a substance meets, or does not meet, the criteria for a new hazard class, the six-month deadline as per Article 6 of the Commission Implementing Regulation (EU) 2020/1435 for updating the REACH dossier begins.

For example:

A classification decision taken on 1 May 2025 requires a dossier update by 1 November 2025.
A decision taken on 1 November 2026 requires an update by 1 May 2027.

For lead registrants managing a large portfolio of substances, staggered decision dates across portfolios can create a rolling series of submission deadlines that must be actively tracked.

Documenting “No-Classification” Decisions

In some cases, the available data in the REACH dossier will be insufficient to conclude on a classification; however, the absence of a definitive classification conclusion due to insufficient data in the REACH dossier should be formally documented within the dossier. This is considered best practice, as regulators expect dossiers to reflect the most current hazard evaluation, which demonstrates regulatory readiness, provides transparency, and reduces risk.

Lead registrants should proactively encourage co-registrants to align on and document these conclusions to ensure consistency across the joint submission.

For higher tonnage registrations, any change in the hazard profile (newly classified or confirmed as not applicable) must be consistently reflected in the CSR across the hazard assessment, DNELs/PNECs, exposure scenarios, and risk management measures.

A classification review can have knock-on effects that broaden into a wider regulatory and commercial exercise, including the revision of exposure scenarios, updates to extended Safety Data Sheets (e-SDSs), communication obligations along the supply chain, and potential impacts on authorisation or restriction.

Recommendations for Lead Registrants

To manage the regulatory, operational, and commercial risks created by the new CLP hazard classes, lead registrants should move beyond reactive dossier updates and adopt a structured, portfolio-wide implementation strategy.

Start with prioritising substances based on both regulatory risk (the likelihood of re-classification and data gaps) and commercial exposure.
Engage co-registrants early to agree on interpretations and cost-sharing, preventing submission delays. New testing or data evaluation costs will need to be fairly distributed across co-registrants.
Update IUCLID Sections 2 and 7–10 to support new classifications if required.
Re-evaluate existing study summaries using the new criteria, particularly for endocrine disruption.
Assess the impact of classification changes on Chemical Safety Reports (CSRs), derived no-effect levels (DNELs/PNECs), exposure scenarios, and supply-chain communications as early as possible.
Update classifications cascade into safety data sheets and supply chains, so downstream registrants will expect action before the official deadlines.

Yordas Group has developed a Tiered approach to assessing the impact of the changes to CLP as they apply to Lead Registration dossiers. This ensures that we deliver our technical input most cost-effectively for our clients.

Tier 1, Initial Screening Phase: Yordas will conduct a preliminary screening of your substances against the new hazard class criteria. This initial step will use existing data from the REACH dossier, publicly available information, QSAR models, relevant lists where applicable. The goal is to quickly identify potential concerns without unnecessary full assessments.
Tier 2, Full Assessment Phase: For substances identified as potentially a potential concern during the screening, Yordas will perform a comprehensive hazard evaluation. This will involve an in-depth review of all available data, identification of any data gaps, and, if needed, recommendations for future testing strategies. Yordas will also ensure the REACH dossier is updated to reflect the new CLP hazard classes.

In most cases, a Tier 1 screening should be sufficient based on the available data in the REACH dossier and publicly available sources to meet your obligations under REACH.

In parallel, Yordas’ Helix SDS Manager and hazard communication services ensure that dossier updates are translated into controlled SDS and labelling changes, with clear version management and supply chain alignment.

For lead registrants, this is not a single update but a structured REACH maintenance exercise requiring governance, documented decisions, and controlled timelines.

If you are responsible for a lead registration or joint submission, now is the time to review your portfolio against the new CLP hazard classes. Yordas can work alongside you to assess the impact and build a clear, prioritised dossier update plan aligned to the upcoming deadline.

Contact our REACH specialists to begin.