Moving persistence (P) assessments into the 21st Century: Developing a new paradigm to assess degradation potential of chemicals

Background

Recent progress in the scientific understanding of the underlying processes of persistence and degradation has provided an opportunity to develop an improved framework and best practices for persistence and degradation assessments.

Recent research activities have covered topics such as: Role of microbial community in degradation testing (adaptation, variability); Challenges in conduct and interpretation of simulation tests, including considerations regarding bioavailability and system-dependent variation; Non-extractable residues formation; Effect of concentration, co-metabolism and temperature on degradation kinetics.

Terms of Reference

1. Revisit the principles for P assignments of organic chemicals in the context of new research
2. Review recent research activities and assimilate the key aspects to improve and expand experimental design and strategies
3. Translate the key research findings into a framework document considering new concepts relating to defining persistence
4. Identify gaps and propose follow-up work/ research projects to fill those gaps

Timing and deliverables

The Task Force held their kick-off meeting in July 2019 and submitted two manuscripts to a peer reviewed journal in January 2021. The first publication focusses on scientific concepts and methods to improve P assessment. The second publication proposes a conceptual framework to move P assessments into the 21st Century.

The Task Force co-chaired the joint session “Persistent (P) and PMT/vPvM Substances in the Environment: Improving Experimental and Weight of Evidence Assessment Methods, Providing Solutions, and Informing Regulations” at the virtual SETAC Europe meeting in May 2020. Here, the Task Force presented its progress within one platform presentation titled “Moving persistence (P) assessments into the 21st Century: Developing a new paradigm to assess degradation potential of chemicals” and with two poster presentations titled “Conceptual framework for moving persistence (P) assessments into the 21st Century” and “Scientific concepts and methods for moving persistence (P) assessments into the 21st Century”.

The Task Force hosted a webinar in  September 2020 to share their recommendations with key stakeholders and receive feedback.

The Task Force published the following two papers in IEAM in 2021: Redman et al., 2021 ‘Moving persistence assessments into the 21st century: A role for weight‐of‐evidence and overall persistence’ and Davenport et al. 2021 ‘Scientific concepts and methods for moving persistence assessments into the 21st century’.

The Task Force’s work is currently being further disseminated via the ECETOC ‘Persistence assessment in 21st Century – Dissemination Platform’.