httk

is a Data Source.

It is part of the NAMs collection.

High-Throughput Toxicokinetics (httk) is a US EPA R package that provides free, open-source data and models for toxicokinetics (TK). It pairs chemical-specific in vitro measurements and in silico predictions, available for thousands of chemicals, multiple exposure routes, and several species, with generic physiologically based (PBTK) and empirical TK models. The package supports traditional dosimetry and in vitro to in vivo extrapolation (IVIVE), including reverse dosimetry that converts high-throughput screening concentrations (e.g., from ToxCast and Tox21) into equivalent real-world exposures.

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Domains

toxicology, pharmacology, chemistry and biochemistry, environmental exposure, environment, software, information technology

License

MIT

Homepage

httk

Repository

GitHub

External IDs

Product Summary

Products

From this Resource
ID Name URL Category Format Description
httk.package httk R Package package=httk Process r The httk R package on CRAN, bundling ...
httk.repository httk GitHub Repository CompTox-ExpoCast-httk Product http GitHub repository for the httk R pack...
From other Resources
ID Name URL Category Format Relation Description
comptox-dashboard.portal CompTox Chemicals Dashboard Web Application dashboard Graphical Interface http was derived from Web interface to the CompTox Chemical...
comptox-dashboard.downloads Downloadable Computational Toxicology Data downloadable-computational-toxicology-data Product mixed was derived from EPA's downloadable computational toxi...

Details

httk (High-Throughput Toxicokinetics)

Overview

httk is a US EPA R package for high-throughput toxicokinetics (HTTK), the combination of chemical-specific in vitro data with generic toxicokinetic models. It links an external dose of a chemical to the resulting internal blood or tissue concentration. This lets users convert bioactive concentrations from in vitro high-throughput screens into estimated real-world exposures through in vitro to in vivo extrapolation (IVIVE). The CompTox Chemicals Dashboard’s ADME/IVIVE data are generated with httk.

Data Content

  • Chemical-specific in vitro toxicokinetic data (e.g., measurements of distribution and metabolic clearance) and in silico predictions for thousands of chemicals, multiple exposure routes, and several species.
  • Generic physiologically based (PBTK) and empirical (e.g., one-compartment) TK models, implemented as compiled ODE systems.
  • A Monte Carlo sampler for human biological variability and parameter uncertainty.
  • Calibrated methods for predicting tissue:plasma partition coefficients and volume of distribution.

Access

  • CRAN: https://CRAN.R-project.org/package=httk (version 2.7.4 at the time of curation)
  • GitHub: https://github.com/USEPA/CompTox-ExpoCast-httk

License

httk is distributed on CRAN under the MIT license (MIT + file LICENSE).

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Created: October 19, 2026 | Last modified: October 19, 2026