CONTRACT RESEARCH & TOXICOLOGY
Other screening RBT
Monitoring data OtherWoe
QSAR Soil
Marine sediment Freshwater sediment
Marine Freshwater
Figure 3 – Persistence conclusions of HBCDD for each LoE
Dataset conclusions - Lines of evidence
0 % 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100 %
■ Persistent ■ Very Persistent ■ Not Persistent
The framework for assessing persistence under REACH is detailed in Annex XIII of the legal text , with guidance provided by ECHA . This requires a weight of evidence ( WoE ) approach , with various other types of information considered relevant along with the compartmental degradation half-lives , such as computational predictions , field data and screening studies .
Concerns have been raised previously around the overall lack of guidance on WoE , and that decisions may often lack consistency , transparency and robustness . Recently , substantial progress has been made in defining WoE approaches for chemical assessments in general . However , substantial gaps remain in the guidance available to evaluate the quality ( reliability and relevance ) of diverse information on persistence , and how to combine this to arrive at a single conclusion .
The outcomes of persistence assessments can lead to severe business consequences for private sector organisations in the chemical and downstream sectors globally . These include , among other things , whether a substance can be placed on the market , the costs of compliance , and market and reputation implications .
Furthermore , regulators need clear and robust approaches for evaluating data and carrying out persistence assessments in order to take effective decisions . Therefore , guidance is urgently needed for manufacturers and importers of chemical products , regulators and the scientific community , so that they can understand and carry out these assessments robustly .
Ricardo tool
To address these challenges and support the evaluation of persistence under regulatory frameworks such as REACH , Ricardo has developed a software tool , the Persistence Assessment Tool ( PAT ). This is based on the expertise of Ricardo ’ s National Chemical Emergency Centre ( NCEC ) in chemical safety support and emergency response .
The development of the tool was sponsored by Concawe and the International Collaboration on Cosmetics Safety ( ICCS ), with support from CEFIC ’ s Long-Range Research Initiative ( LRI ) and the European Centre for Ecotoxicology & Toxicology of Chemicals ( ECETOC ). It can be downloaded for free at : www . ricardo . com / pat .
The PAT provides clear guidance and structure to evaluate data quality , and a quantitative WoE methodology to process the information input and calculate persistence conclusions in line with regulatory guidance . It is applicable to all substance types and provides specific features to account for difficult and complex substances .
Various options for customisation of the methodology are included to adapt assessments to specific regulatory frameworks and purposes . In addition , a multimedia fate model , based on the EU-adopted SimpleBox model , is included to optionally calculate overall persistence ( POV ), allowing for additional potentially important environmental fate processes to be considered . The PAT aims to support robust , consistent and transparent decision-making for persistence assessment .
Materials & methods
Available persistence assessment criteria , test guidelines and guidance were extracted and converted into rules and logical tests , which could be coded into software . The methodology that was implemented followed a stepwise approach to evaluate and then combine persistence data ( Figure 1 ).
JUL / AUG 2023 SPECCHEMONLINE . COM
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