On December 12, 2025, the European Union formally adopted the One Substance, One Assessment (OSOA) legislative package. This initiative marks a major milestone in European chemical regulation. Its goal is to streamline chemical risk assessments and strengthen the protection of human health and the environment.

The Three Core OSOA Legislative Acts

The OSOA package is built around three key legislative acts:

• Regulation (EU) 2025/2455 establishes a common data platform for chemicals. It ensures that chemical information is findable, accessible, interoperable and reusable (FAIR). The regulation also introduces a monitoring framework to track chemical risks and regulatory responses.
• Directive (EU) 2025/2456 amends the Restriction of Hazardous Substances (RoHS) Directive. It reallocates scientific and technical tasks to the European Chemicals Agency (ECHA).
• Regulation (EU) 2025/2457 amends several EU laws, including food law, the EEA regulation, the Medical Devices Regulation and rules on persistent organic pollutants (POPs). The changes improve cooperation and task-sharing between EU agencies such as ECHA, EFSA and the EEA.

Faster and More Consistent Risk Assessments

Together, these new rules streamline the EU’s approach to chemical risk assessment. They shorten the time between identifying a potential hazard and taking regulatory action. According to the European Commission, this will lead to faster and more effective protection of public health and the environment.

The OSOA framework also improves the quality, consistency and efficiency of chemical safety assessments. It applies across multiple sectors, including medical devices, toys, food, pesticides and biocides.

A Common Data Platform Managed by ECHA

A central element of the initiative is the creation of a common data platform managed by ECHA. The platform will serve as a one-stop shop for chemical information. It will integrate existing data from more than 70 EU legislative frameworks.

The platform will cover chemical hazards, physico-chemical properties, environmental presence, emissions and uses. It will also host a database of safer alternatives, supporting the EU’s transition toward safer and more sustainable substances.

Better Use of Scientific Expertise

The OSOA package clarifies which EU agency is responsible for specific scientific and technical tasks. By improving cooperation and reducing overlaps, the EU expects to deliver chemical assessments more quickly and more consistently. This approach also enables earlier detection of emerging risks and more timely regulatory intervention.