Supplementary data for: Application of in vitro to in vivo extrapolation (IVIVE) to inform chemical health guidance value derivation – sample case studies comparing neuro-, hepato-, and developmental toxicities
Data files
Mar 06, 2026 version files 71.35 KB
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R1_Supplemental_Tables_v2.zip
65.37 KB
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README.md
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Abstract
Traditional chemical risk assessment is often based on published mammalian in vivo toxicity data, which are used to identify a point-of-departure (PoD) to derive the minimal risk level (MRL) and similar health guidance values. However, time and resource requirements prohibit efficient multi-target-organ toxicity assessments for a large number of environmental chemical pollutants. In vitro high-throughput screening (HTS) assays and other new approach methodologies (NAMs) could address this problem by using reverse dosimetry to contextualize activity concentrations obtained from the in vitro assays to in vivo settings. In this study, we selected a sample priority of diverse chemicals for which both curated high-throughput screening (cHTS) assay data and acute oral MRLs were available for neurotoxicity, hepatotoxicity, and developmental toxicity. We obtained in vitro activity concentrations for these chemicals and conducted in vitro to in vivo extrapolation (IVIVE) to estimate the daily equivalent administered dose (EAD) that would result in rat or human plasma concentrations equivalent to the in vitro activity concentrations. The range of EAD values across various cHTS assays was then compared to in vivo PoDs, MRLs, and predicted human exposure levels. Although variations existed depending on the toxicity endpoints evaluated, our results showed that PoDs for a majority of chemicals can be predicted using such data. Our results also demonstrated that a majority of MRL and EAD values fall well below predicted human exposure levels. In summary, our findings demonstrate the usefulness and limitations of using cHTS data and IVIVE approaches for the derivation of health guidance values.
This dataset consists of supplemental tables organized as spreadsheets containing chemical-specific physicochemical and pharmacokinetic parameters; in vitro cHTS assay data; cHTS assay annotations extracted from ICE, MRLs, and in vivo PoDs across different toxicity endpoints; EAD values estimated using the ICE IVIVE tool; and predicted human exposure. Data values include numeric data (e.g., in vivo PoDs and EADs) and categorical descriptors (e.g., chemical identifiers and toxicity endpoints). The dataset is structured to allow independent verification and reanalysis of the results reported in the associated manuscript. All data are derived from publicly available sources or computational tools and contain no proprietary information. There is no legal restriction on reuse.
These supplemental tables include EADs, MRLs, and in vivo PoDs across different toxicity endpoints, in vitro cHTS assay data, chemical-specific model input parameters, mechanistic targets, and modes of action for selected in vitro cHTS assays. The data support the transparency and reproducibility of the results reported in the associated manuscript.
Dataset DOI: 10.5061/dryad.tx95x6bbj
Description of the data and file structure
The in vitro and in vivo data were collected from publicly available data resources. IVIVE analyses were conducted using open-source data and tools within the Integrated Chemical Environment (ICE: https://ice.ntp.niehs.nih.gov/) Any empty cells represent data not available.
Files and variables
Supplemental Tables: R1_Supplemental_Tables_v2.zip
Supp. Table 1. EADs, MRLs, and in vivo PoDs for all three toxicity endpoints. The table includes EADs, MRLs, in vivo PoDs, and uncertainty factors applied by ATSDR to derive the MRLs. The type of in vivo PoD (e.g., NOAEL, LOAEL, or BMDL) for calculating MRLs for each chemical is also included. Data source for in vivo PoDs: https://wwwn.cdc.gov/TSP/MRLS/mrlslisting.aspx; https://www.atsdr.cdc.gov/mrls/pdfs/ATSDR-MRLs-December-2024-H.pdf. #, Maximum tested concentration (100 μM) from cHTS assay were used for IVIVE; ACC, activity concentration at cutoff; BMD, benchmark dose (maximum likelihood estimate of the dose associated with the selected benchmark response); BMDL, 95% lower confidence limit of the BMD; CASRN, Chemical Abstracts Service Registry Number; cHTS, curated high-throughput screening; DTXSID, DSSTox Substance Identifier (a unique identifier assigned by the U.S. EPA to chemical substances in its Distributed Structure-Searchable Toxicity [DSSTox] database); EAD, equivalent administered dose; ICE, Integrated Chemical Environment; maxEAD, maximum equivalent administered dose; medEAD, median equivalent administered dose; minEAD, minimum equivalent administered dose; MRL, minimal risk level; OBO, Open Biological and Biomedical Ontology; PoD, point of departure; SD, standard deviation; UF, uncertainty factor; vs., versus.
Supp. Table 2. In vitro cHTS data from ICE used for IVIVE. ACC, activity concentration at cutoff; CASRN, Chemical Abstracts Service Registry Number; DTXSID, DSSTox Substance Identifier (a unique identifier assigned by the U.S. EPA to chemical substances in its Distributed Structure-Searchable Toxicity [DSSTox] database).
Supp. Table 3. Chemical-specific physicochemical and pharmacokinetic parameters. Clint, in vitro intrinsic clearance; fu, fraction of chemical unbound to plasma protein; MW, molecular weight.
Supp. Table 4. EAD values estimated with the ICE IVIVE tool using rat httk.pbtk model. EAD_User Data: Max. Test Conc., equivalent administered dose using the maximum tested concentration (100 μM) in the cHTS assay; max_RatEAD, maximum equivalent administered dose (rat); med_RatEAD, median equivalent administered dose (rat); min_RatEAD, minimum equivalent administered dose (rat); Plasma Cmax, maximum plasma concentration.
Supp. Table 5. Mechanistic target and mode-of-action terms for selected in vitro cHTS assays extracted from ICE (v4.1) and mapped to OBO Foundry ontologies. aeid, assay endpoint identification numbers from invitrodb v3.5; KCC, Key Characteristic of Carcinogens; GO, Gene Ontology; NCIT, National Cancer Institute Thesaurus; OBO, Open Biological and Biomedical Ontology; OBO ID, the unique identifier assigned within an OBO Foundry ontology; TXPO, TOXic Process Ontology.
Supp. Table 6. EAD values estimated using the ICE IVIVE tool using the human httk.pbtk model. EAD_User Data: Max. Test Conc., equivalent administered dose using the maximum tested concentration (100 μM) in the cHTS assay; max_HumEAD, maximum equivalent administered dose (human); med_HumEAD, median equivalent administered dose (human); min_HumEAD, minimum equivalent administered dose (human); Plasma Cmax, maximum plasma concentration.
Supp. Table 7. Comparison of human EAD values with predicted human exposure from the U.S. EPA SEEM3 model. CASRN, Chemical Abstracts Service Registry Number; DevTox, developmental toxicity; EAD, equivalent administered dose; HepatoTox, hepatotoxicity; min_HumEAD, minimum equivalent administered dose (human); MRL, minimal risk level; NeuroTox, neurotoxicity.
Code/software
The data are provided as spreadsheet files and can be viewed using Microsoft Excel or compatible open-source spreadsheet software. No additional software, code, or scripts are required.
Access information
Data was derived from the following sources:
- Integrated Chemical Environment (ICE: https://ice.ntp.niehs.nih.gov/)
