ECETOC Task Force assesses methods to improve evaluation of chemical persistence

A Task Force from the Centre for chemical safety assessment (ECETOC) has just published its findings on improving methods to evaluate a chemical’s persistence in the environment in the peer-reviewed journal Integrated Environmental Assessment and Management (IEAM).

The study was prompted by recent progress in scientific understanding of the underlying processes of persistence and degradation which provided the Task Force with the opportunity to develop an improved framework and best practices for persistence and degradation assessments.

Chemical persistence in the environment is one of the most important criteria in the regulation of organic chemicals. Besides being used for prioritising hazardous chemicals, it is central to determining chemical exposure and any subsequent risk to the plant and animal life of a region.

Chemical pollution is one of nine factors identified that threaten to destabilise our Earth system processes. The effects of chemical exposure due to human activities is thus one of humanity’s greatest challenges. In this context, persistence (P) has been proposed as a central indicator to help quantify boundaries for different substances in defining a ‘safe operating space for humanity’.

The ‘Moving Persistence Assessments Into The 21st Century’ Task Force looked at both the challenges and the limitations facing current test methods and the scientific advances that are helping to understand and provide solutions to them.

In regulatory persistence assessment regimes, the processes involving microbes transforming chemicals are considered to be the most important. This is because micro-organisms are ubiquitous and so impact where a chemical goes when it gets into the environment and how it might be chemically transformed in the process. These processes are the focus of the Task Force’s paper.

The Task Force concluded that, in recent years, the field of biodegradation science had made significant advances that could help to improve the precision and accuracy of persistence assessments. But without effectively transforming the advances into standard test methods that receive regulatory acceptance and guidance, and/or use of the knowledge to better inform assessments, their value is limited.

This can be achieved by academia, regulatory bodies, and industry working together more efficiently, so it no longer takes more than 10 years for new science to be incorporated into testing methods, which then only achieve regulatory acceptance some time later. Science can help develop robust, technically acceptable methods so that appropriate decisions can be made about the persistence of test substances.

In a second ‘companion paper’ also published by IEAM, the Task Force looks at the regulatory framework for assessing the persistence of chemicals in the environment to protect human health and ecosystems.