ECHA’s new Chesar platform unifies REACH and biocides risk assessment tools
Last update on Jun 9, 2026
Chemical safety assessment professionals working under REACH or biocides regulations can now access a unified risk assessment environment with the first release of ECHA's Chesar Platform, available through ECHA Cloud Services.
The Chesar Platform is designed to replace three separate tools currently in use: the existing Chesar 3 application, EUSES 2.2.0, and ECHA's Excel-based calculation tools for biocides. According to ECHA, the new environment brings these assessment approaches together in a single, modernised interface that supports both regulatory pathways.
You can review and compare REACH-compliant ingredients directly in the Master Catalog of Adhesives.
What the platform covers
For REACH users, the Chesar Platform supports chemical safety assessments and the generation of chemical safety reports, along with exposure scenarios for safety data sheets. For biocides users, it supports environmental exposure and risk assessments of individual active substances, and covers the relevant sections of the Risk Assessment Report and Competent Authority Report.
ECHA indicates that the platform provides a structured workflow for chemical risk assessment, with embedded exposure estimation tools and harmonised reporting functions. Calculations are refreshed and reports regenerated automatically when assessment inputs are updated, a change that reduces manual rework across assessment cycles. These functions are further enhanced when substance information is synchronised with IUCLID, ECHA's data management system for substance registrations.
ECHA also notes that updated exposure assessment models are available exclusively in the Chesar Platform, and that the latest scientific updates will not be backported to earlier tools.
What this means for your assessment workflow
The previous Chesar 3 tool will remain supported for approximately one year to allow users to transfer existing assessments and familiarise themselves with the new environment. ECHA has released migration guidance, a user manual, and release notes alongside the platform launch. A webinar covering the platform's main functionalities and onboarding process was held on 2 June 2026.
If you conduct chemical safety assessments under REACH or environmental risk assessments under the biocides regulation the Chesar Platform consolidates the tools required for both into a single, cloud-based environment. ECHA recommends that users begin transitioning to the new platform now, while Chesar 3 support remains available.