An official website of the United States government.

We've made some changes to If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Toxicity ForeCaster (ToxCast™) Data

EPA's most updated, publicly available high-throughput toxicity data on thousands of chemicals. This data is generated through the EPA's ToxCast resesarch effort. ToxCast is part of the Toxicology in the 21st Century (Tox21) federal collaboration. All data is available for download and includes the following data sets. The release date and version names for the data sets are provided in the table below.

As part of EPA’s commitment to share data, all of the computational toxicology data is publicly available for anyone to access and use. EPA's computational toxicology data is considered "open data", and thus all of the data below are free of all copyright restrictions, and fully and freely available for both non-commercial and commercial use.

Data Set Description Release Date Database Version Download
ToxCast & Tox21 Chemicals Distributed Structure-Searchable Toxicity Database (DSSTox files) Chemical details for 8,599 unique substances (GSIDs) and DSSTox standard chemical fields (chemical name, CASRN, structure, etc.) for EPA ToxCast chemicals and the larger Tox21 chemical list. Also includes chemical mapping files and quality control grades for chemicals. October 2015

ToxCast Chemicals: Data Management and Quality Considerations Overview

Download ToxCast Chemical Information

Download ReadMe

ToxCast & Tox21 high-throughput assay information ToxCast high-throughput assay information including assay annotation user guide, assay target information, study design information and quality statistics on the assays. October 2015


Assay Annotation User Guide

Download Assay Information

Download ReadMe

Standard Laboratory Protocol for Tox21 Assays Data describing the standard laboratory protocol for Tox21 assays including descriptions of Tox21 assays, protocol for all assays (reference, quality control, procedures and performance) and assay data.   March 2016   Download Standard Laboratory Protocol for Tox21 Assays
ToxCast & Tox21 Summary Files Data for a single chemical endpoint pair for thousands of chemicals and 821 assay endpoints for 20 variables such as the activity or hit call, activity concentrations, whether the chemical was tested in a specific assay, etc. October 2015

Download ToxCast Summary Information

Download ReadMe

MySQL Database A downloadable database that provides users access to all ToxCast and Tox21 high-throughput in vitro data. The downloadable ToxCast Data Pipeline Overview file provides a summary of how EPA processes and analyzes ToxCast data. October 2015

Download MySQL Database

ToxCast Data Pipeline Overview

R Package The R computer programming package used to process and model all EPA ToxCast and Tox21 chemical screening data. The files include the R programming package as well as documents that provide overviews of the data analysis pipeline used and the R package. Users will need experience with R to use these files. May 2016


Download from GitHub
ToxCast & Tox21 Data Spreadsheet A spreadsheet of EPA's analysis of the chemicals screened through ToxCast and the Tox21 collaboration which includes EPA's activity calls from the screening of over 8,000 chemicals. October 2015

Download Data

Download ReadMe

ToxCast & Tox21 Concentration Response Plots Concentration response plots for all of the ToxCast and Tox21 assays. October 2015
Download Concentration Response Plots
OECD GD 211 ToxCast Endocrine-Related Assay Documentation

Descriptions and guidelines for ToxCast endocrine-related assays in format outlined by the OECD Guidance Document 211 for  describing non-guideline in vitro test methods. The intent of GD 211 is to harmonize non-guideline, in vitro method descriptions to allow assessment of the relevance of the test method for biological responses of interest and the quality of the data produced. 

October 2017   Download Endocrine-Related Assay Documentation
Collaborative Estrogen Receptor Activity Prediction Project Data Data and supplemental files from CERAPP (A large-scale modeling project) which demonstrated the efficacy of using predictive computational models trained on high-throughput screening data to evaluate thousands of chemicals for estrogen-related activity. CERAPP combined multiple models developed in collaboration with 17 groups in the United States and Europe to predict ER activity of a common set of 32,464 chemical structures. Quantitative structure-activity relationship models and docking approaches were employed, to build a total of 40 categorical and 8 continuous models for binding, agonist, and antagonist ER activity.  January 2016 invitrodb_v1

Download Evaluation Set

Download Models

Download Prediction Set

Download Training Set

High-throughput screening data for estrogen receptor model Estrogen receptor model data from the manuscript titled Integrated Model of Chemical Perturbations of Biological Pathways Using 18 In Vitro High-throughput Screening Assays for the Estrogen Receptor (Judson et al) published in Toxicological Science.  August 2015 invitrodb_v1 Download Data
Animal Toxicity Studies: Effects and Endpoints (Toxicity Reference Database - ToxRefDB files)

Provides results from across the thousands of animal toxicity studies:

  • No Effect Level (NEL)/Lowest Effect Level (LEL) and/or
  • No Observed Adverse Effect Level (NOAEL)/Lowest Observed Adverse Effect Level (LOAEL)
October 2014


Download Animal Toxicity Data

Download ReadMe

Previously Published ToxCast Data Data files from previously published ToxCast data releases. We DO NOT recommend using this data for new analyses, but are providing these files in case users need them for ongoing analyses. Various Various Download Previously Published ToxCast Data

General citation suggestion

USEPA. Data download year. Data set name from database version. Retrieved from on date retrieved. Data release date.

Example citation

USEPA. 2015. ToxCast & Tox21 Summary Files from invitrodb_v2. Retrieved from on October 28, 2015. Data released October 2015.