This article follows-up on our previous Blog Post exploring the “jargon” of the EU Commission’s Chemicals Strategy for Sustainability (CSS), an ambitious political action plan for chemicals regulation in the EU that was released in October 2020.

Today, we are digging into another key concept of the CSS: the concept of “one substance, one assessment” (hereafter referred to as “OSOA“), which is essential for the Commission, and more generally for the European Union, to simplify and consolidate the chemicals legal framework.

The Need for OSOA

The Commission observes that, at present, the existing assessment procedures for chemicals are very complicated for stakeholders and, in the language of the CSS “can lead to inconsistencies, slow procedures, inefficient use of resources and unnecessary burdens.” This is the consequence of having several EU legislations for chemicals with different agencies conducting regulatory assessments, each being supported by various scientific committees and/or expert groups.

For this reason, the Commission explains in the CSS that it plans to develop a new policy named OSOA to accomplish the following key objectives: making chemicals assessment processes simpler and more transparent, reducing the burden on stakeholders, and making decision-making faster, as well as more consistent and predictable.

OSOA: Background

Essentially, OSOA should reshape the future of chemicals assessment in the EU. It should restructure and reorganize the way chemicals assessment should be achieved. This may hopefully ensure coherence of EU regulatory action. For example, the task of conducting chemicals assessment could be assigned to one EU agency rather than several, as is the case today. Among others, the reorganization of the role of each EU agency in the assessment of chemicals is considered as an option.

If the CSS does not seem clearly to break off with the current state of play, the Commission unveiled a more detailed and ambitious policy during the 40th Caracal Meeting of 29 and 30 June 2021, which notably reallocates the agencies’ tasks and responsibilities.

The Commission has specified in the CSS that OSOA will concern several agencies, namely the European Food Safety Authority (EFSA),  the European Chemicals Agency (ECHA), the European Medicines Agency (EMA) and the European Environment Agency (EEA). Furthermore, ECHA and EFSA have endorsed some aspects of OSOA in October 2020, when they issued a joint position paper entitled “In support of the EU chemicals strategy for sustainability: One substance – one assessment”, a common understanding which was further discussed at the occasion of the 80th Meeting of the EFSA Advisory Forum that took place on 9 and 10 June 2021.

OSOA is a fairly recent concept but is not born with the CSS. It existed in former policy documents of the Commission as well as in the Parliament resolution “Chemicals strategy for sustainability”. Moreover, before the CSS release, the Executive Director of ECHA had already taken the opportunity of the ECHA’s Virtual Safer Chemicals Conference (which took place the 2 June 2020) to expose his views on the concept’s implications.

OSOA: Details

OSOA is displayed as a multi-pillar policy by the Commission, composed of four pillars, each linked to separate work streams and scheduled for the upcoming years – between now and 2024. We provide below details on each pillar, on the basis of the information currently available.


The first OSOA pillar is the initiation phase, during which coordination mechanisms will be developed. The Public Activities Coordination Tool (PACT), a dynamic table accessible on the ECHA website, will be expanded to all relevant legislation as the basis for improved coordination. PACT currently tracks actions under REACH and CLP, i.e., it provides an overview of all planned and ongoing initiatives on the safety of chemicals under those two regulations.

More specifically, PACT currently provides up-to-date information on the activities planned, ongoing or completed by ECHA and/or Member State Competent Authorities for a given substance in the following areas:

  • Data generation and assessment – dossier evaluation, substance evaluation, informal hazard assessment (PBT/vPvB/ED).
  • Assessment of regulatory needs (ARN).
  • Regulatory risk management – harmonised classification and labelling (CLH), SVHC identification, restriction.

The Commission wants to expand PACT to all safety assessment legislation processes, leading to better readability of all planned and ongoing assessments of chemicals.

In addition to PACT, an inter-service group would be created within the Commission to coordinate actions on chemical assessment across legislations, and an Expert Working Group of Member States including the Commission services and Agencies is to be set up to support the implementation of OSOA.


The second pillar will be the allocation phase, consisting of the redistribution of work between agencies. The Commission plans to propose a horizontal legislative act on the reallocation of EU technical and scientific work on chemicals. Accordingly, the respective legal texts organizing chemicals assessment should be amended to reflect the reallocation of tasks and responsibilities of EFSA, ECHA, EMA and EEA. This is expected by 2023.

Though it is unclear to what extent it would contribute to OSOA, the Commission has announced a proposal to strengthen the governance of ECHA and increase the sustainability of its financing model by 2023 as part of the allocation stage.


Third, several key actions will be taken regarding data. One core initiative will be the creation of a common open data platform on chemicals to be set up by 2023, i.e., a single access point to data and information on chemicals in the EU. According to the CSS, this platform will “facilitate the sharing, access and re-use of information on chemicals coming from all sources”. This open data platform raises certain important questions – such as those identified by Cefic in a position paper of May 2021 “Cefic views on the Open Data Platform” – including the extent to which it will replace the existing ECHA dissemination portal and OpenEFSA portal.

Another key action is the harmonization on the data format, i.e., a shift towards IUCLID for hazard and use data, and to IPCHEM for monitoring data, as well as the creation of tools for making academic data suitable and easily available for regulatory purposes by 2023.

Finally the adoption of a legal act is expected to amend the existing legislations with respect to the way data are handled and reported. This will allow a streamline of all data owned by EU agencies, and ensure that those data are reused pursuant to open data and transparency principles. It may also affect the powers of agencies to commission testing and to monitor substances.


The fourth and last building block relates to methodology. Essentially, it consists of the harmonization of human health and environment-based safety values (e.g., predicted no-effect concentrations (PNECs) or derived no-effect levels (DNEL)) and of the creation of a Centralized EU repository of human and environmental health-based limit values to promote reuse of health-based limit values by 2022.

How can we help ?

The Mayer Brown regulatory team has longstanding experience on chemicals legislation, with expertise dating back long before the development of REACH. We have a thorough knowledge of the legislative evolutions affecting this field, which we can use to advise on the significant reforms to come.