Understanding chemical behavior in the environment is a fundamental aspect of chemical hazard and risk assessment. Chemical bioaccumulation is a complex process and there are multiple lines of evidence and metrics that can be used in bioaccumulation assessment. The Bioaccumulation Assessment Tool (BAT) facilitates the systematic and transparent integration of information in a consistent framework to inform bioaccumulation assessment decision-making. The BAT provides a Weight of Evidence approach that is aligned with the Guiding Principles and Key Elements for Establishing a Weight of Evidence for Chemical Assessment provided by the Organization for Economic Coordination and Development (OECD).
The BAT is a user-friendly, spreadsheet-based tool to guide the collection, generation, evaluation, and integration of various lines of evidence for aquatic and air-breathing (mammalian) organisms. The BAT includes guidance for the critical evaluation of data confidence for all lines of evidence and summarizes the overall Strength of Evidence based on user selected bioaccumulation assessment metrics and criteria. Not only can these data confidence scoring methods be useful for evaluating bioaccumulation and toxicokinetics data being used in the BAT, but these data evaluation templates can also be used when considering bioaccumulation and toxicokinetics data quality in general.
BAT Ver.1.0 was publicly released in October 2018 following its development with input from a multistakeholder community. Based on further engagement and case study applications (see Armitage et al., 2021), the BAT was revised, with funding support from CEFIC LRI and ACC LRI, to improve assessment capacity and workflow. BAT Ver.2.0 has several new features, including:
- Capacity to include in vivo mammalian laboratory testing data;
- Capacity to include in vivo invertebrate laboratory testing data;
- Revised In Vitro-In Vivo Extrapolation (IVIVE) models for integrating in vitro biotransformation rate data for fish and mammals;
- User options for entering chemical dietary absorption efficiency for fish and mammals;
- Increased capacity for including field bioaccumulation data;
- Improved workflow for changing input data and user options;
- Capacity to include propagation of uncertainty in biotransformation half-life and chemical absorption efficiency data in BAT models for calculating a suite of bioaccumulation metrics for fish and homeotherms including the bioconcentration factor (BCF), bioaccumulation factor (BAF), biomagnification factor (BMF) and total elimination half-lives (HLT).
BAT Ver.2.0 is now freely and publicly available for download at the ARC Arnot Research and Consulting website.
Other resources at the ARC website include BAT Ver.2.0 instructional video vignettes and recordings of recent relevant webinars hosted by HESI.