ECOTOX Database: EPA Ecotoxicology Data Guide

The ECOTOXicology Knowledgebase (ECOTOX) is an open-access ecological toxicity database developed and maintained by the United States Environmental Protection Agency (EPA). It provides single-chemical toxicity test results for aquatic life, terrestrial plants, and wildlife. Built to support environmental risk assessment and chemical safety evaluation, ECOTOX systematically indexes peer-reviewed scientific literature to provide standardized, empirical ecotoxicity endpoints. Environmental testing laboratories and ecotoxicology researchers use the database to establish chemical hazard benchmarks, calibrate bioassays, and evaluate environmental thresholds alongside the CompTox Chemicals Dashboard and foundational toxicology research methodologies.

What it is

The ECOTOX database serves as the official ecological toxicity repository of the U.S. EPA Office of Research and Development. Rather than calculating predictive models or storing uncurated laboratory data streams, ECOTOX compiles empirical test results extracted from primary research publications and verified historical databases. The knowledgebase aggregates studies that examine the effects of single chemical substances on ecological species under controlled laboratory or field conditions.

Each record in ECOTOX is standardized through controlled vocabularies and unified units of measurement. The database links biological effect measurements—such as mortality, growth, reproduction, physiological alterations, and biochemical endpoints—to specific test organisms, chemical identifiers, exposure media, test durations, and literature citations. Analytical testing facilities rely on these standardized records to benchmark experimental bioassay data against validated literature thresholds.

Who runs it and what it covers

ECOTOX is maintained by the EPA Office of Research and Development (ORD), Center for Computational Toxicology and Exposure (CCTE), through its Great Lakes Toxicology and Ecology Division (GLTED) based in Duluth, Minnesota. The system originated in the 1980s by uniting three independent EPA databases:

• AQUIRE (Aquatic Information Retrieval): Ecotoxicity data for freshwater and marine organisms.
• TERRETOX: Terrestrial wildlife toxicity data focusing on birds, mammals, amphibians, and reptiles.
• PHYTOTOX: Terrestrial plant toxicity data covering both agricultural and native plant species.

In its current release (Version 5.6), the ECOTOX Knowledgebase indexes more than 12,000 chemical substances, over 1,000,000 empirical test results, and more than 50,000 primary scientific references (Olker et al., 2022). Newly abstracted literature is added on a quarterly schedule. Environmental laboratories performing bioassays that contribute to ecological compliance must maintain rigorous quality systems, including verified proficiency testing and external quality assessment and strict sample chain of custody documentation.

Minimum data requirements and curation criteria

To maintain scientific credibility in regulatory applications, EPA curators evaluate candidate publications against formal minimum data requirements (codified in EPA/600/R-24/206). Publications and data points failing to satisfy these criteria are excluded from the database:

Parameter	Inclusion Criteria	Exclusion Criteria
Chemical Stressor	Single chemicals with verifiable Chemical Abstracts Service (CAS) Registry Numbers and DSSTox substance identifiers (DTXSID).	Complex chemical mixtures (petroleum fuels, effluents, tank mixes), ambient air pollutants (gaseous ozone, CO2, unless dissolved in water), microplastics, clay/diatomaceous earth, and biological toxins.
Organism Taxonomy	Ecologically relevant wild species (plants, aquatic life, wildlife); laboratory/domestic strains accepted only to fill critical data gaps; taxonomy verified against NCBI Taxonomy.	Humans, non-human primates, bacteria, viruses, and yeasts.
Biological Response	Quantified adverse or neutral biological responses to a chemical toxicant (adverse endpoints prioritized).	Exclusively nutritional, beneficial, or agricultural growth promotion responses.
Exposure Quantification	Concurrent quantified chemical concentration, dose, or application rate; sediment tests must report concurrent water concentrations.	Inhalation exposure routes (including intratracheal instillation), lead shot ingestion, sediment-only concentrations lacking water data, and concentrations reported solely on logarithmic scales.
Exposure Duration	Explicitly reported elapsed duration from initial chemical exposure to biological effect measurement.	Studies omitting observation timing or exposure intervals.
Publication Type	Primary peer-reviewed publications with full text in English (or foreign language studies providing an English abstract and translated data tables).	Review articles, conference abstracts lacking experimental detail, and secondary textbooks.

How to search or use it

The ECOTOX user interface organizes query logic into two distinct operations: within a single parameter category, selections combine via Boolean OR (union); across different parameter categories, selections combine via Boolean AND (intersection). Researchers navigating the database should follow these operational steps (EPA/600/S-24/207):

1. Navigate to the Search interface: Open the EPA ECOTOX website (cfpub.epa.gov/ecotox) and select the Search tab. Avoid using browser back buttons during query building, as browser caching resets active form parameters.
2. Enter chemical identifiers: Open the All Chemicals section. Enter a chemical name or CAS Registry Number (formatted with hyphens such as 121-75-5 or unformatted such as 121755). Alternatively, select from predefined chemical groups (such as organophosphates, pyrethroids, or heavy metals).
3. Select taxonomic groups: Open the All Species section. Enter the organism scientific binomial name (such as Daphnia magna or Pimephales promelas) or common name, or select predefined ecological classes (such as fish, amphibians, or terrestrial insects).
4. Specify toxicological endpoints: Open All Endpoints or All Effects. Choose concentration-based statistical endpoints (such as LC50, EC50, NOEC, or LOEC) or broad effect categories including mortality, reproduction, growth, physiology, or biochemistry.
5. Filter exposure conditions: Open All Test Conditions to constrain exposure media (freshwater, saltwater, soil, artificial substrate), exposure types (flow-through, renewal, static), and study settings (laboratory vs. field).
6. Execute search and export data: Click the Update Search button. Aquatic and terrestrial records are computed separately; click between the Aquatic and Terrestrial tabs to view results. Click Customize Output Fields to select specific variables (such as test chemical purity, water chemistry parameters, or organism life stage), then click Export as… to download an Excel file (.xlsx) or pipe-delimited text file (.txt).

Strengths and limits

Evaluating the ECOTOX database for environmental testing and risk assessment highlights technical capabilities alongside specific operational constraints:

• Comprehensive literature curation: Spanning more than 1,000,000 test results, ECOTOX offers the largest public compilation of curated ecological toxicity data globally, enabling cross-species sensitivity comparisons.
• Controlled vocabulary and standardization: Curators convert diverse concentration units into standardized metrics (such as parts-per-million ratios), facilitating direct toxicological comparisons across published studies.
• Interoperability with EPA resources: Substance records map directly to DSSTox substance identifiers (DTXSID) for integration with CompTox, and species map to NCBI Taxonomy identifiers (TaxID).
• Search export ceiling: The web-based Search module limits individual exports to 10,000 data records. For large queries exceeding 5,000 rows, exporting in pipe-delimited text format is recommended to prevent memory timeouts.
• Query partitioning for high-volume chemicals: For extensively evaluated contaminants that return tens of thousands of records, researchers must partition queries into publication year windows (e.g., 1970–1990, 1991–2005, 2006–2020) and assemble the resulting delimited files externally.
• Explore module display limits: The visual Explore module generates scatter plots of concentration versus duration or effect, but limits browser table rendering to 3,000 records. Comprehensive data extractions require the Search module.
• Bulk ASCII archives: For computational modeling and quantitative structure-activity relationship (QSAR) workflows, researchers can download complete quarterly ASCII database archives directly from EPA’s public file transfer server (gaftp.epa.gov/ecotox).

Testing facilities operating under ISO 15189 accreditation or ISO/IEC 17025 laboratory quality standards routinely benchmark their analytical detection capabilities against these curated toxicological thresholds.

Alternatives

Depending on whether the research objective involves high-throughput in vitro screening, international chemical registration, or ambient field surveys, scientists evaluate ECOTOX alongside complementary chemical databases:

Platform	Operating Organization	Primary Data Focus	Key Distinction vs. ECOTOX
EPA ECOTOX Knowledgebase	U.S. EPA ORD / CCTE	Curated empirical in vivo ecotoxicity tests from peer-reviewed literature.	Comprehensive extraction of whole-organism aquatic and terrestrial wildlife endpoints; excludes mammalian clinical models.
EPA CompTox Chemicals Dashboard	U.S. EPA CCTE	High-throughput in vitro bioassays (ToxCast/Tox21), physicochemical data, and exposure predictions.	Focuses on mechanistic cellular screening and computational predictions; cross-links to ECOTOX via substance DTXSID.
ECHA IUCLID / REACH Database	European Chemicals Agency (ECHA)	Regulatory hazard dossiers submitted by industrial registrants under EU REACH legislation.	Contains industry-submitted regulatory compliance dossiers rather than independently curated academic publications.
OECD eChemPortal	OECD	Global gateway indexing multi-national government chemical assessments.	Aggregates distributed queries across national inventories (including ECOTOX, ECHA, and Japan J-CHECK).
USGS Contaminant Databases	U.S. Geological Survey (USGS)	Environmental water quality monitoring, sediment toxicity, and acute wildlife surveys.	Focuses on ambient field monitoring and geographic watershed surveys rather than systematic literature curation.

FAQ

Does the ECOTOX database include toxicity data for chemical mixtures?

No. ECOTOX restricts its curated dataset to single chemical substances with verifiable CAS Registry Numbers. Complex mixtures, effluent discharges, tank mixes, and environmental field samples with multiple concurrent contaminants are excluded to maintain clear substance-to-effect attribution.

How often is the EPA ECOTOX database updated?

The U.S. EPA updates the ECOTOX Knowledgebase on a quarterly schedule. Each quarterly update incorporates newly curated peer-reviewed publications, updates controlled vocabularies, and releases revised bulk ASCII data files on the public FTP server.

What is the difference between the Search and Explore modules in ECOTOX?

The Search module is built for structured queries using exact chemical names, CAS numbers, taxonomic groupings, or test parameters, allowing users to select custom output fields and export up to 10,000 records. The Explore module provides interactive data visualization, generating plots of exposure concentration against duration or effect, but limits browser table display to 3,000 records.

Can ECOTOX data be cited in regulatory submissions without reviewing original papers?

The EPA explicitly advises researchers and risk assessors to consult original primary scientific papers before applying extracted data in formal regulatory decisions. While ECOTOX curation adheres to strict quality assurance protocols, original papers provide vital experimental context regarding dilution water chemistry, test organism health, and statistical parameters.

Sources

• U.S. EPA ECOTOX 5.6 User Guide (EPA/600/R-24/206), U.S. Environmental Protection Agency Office of Research and Development (2024). Date checked: November 8, 2026.
• U.S. EPA ECOTOX Knowledgebase Quick Guide (EPA/600/S-24/207), U.S. Environmental Protection Agency Office of Research and Development (2024). Date checked: November 8, 2026.
• The ECOTOXicology Knowledgebase: A Curated Database of Ecologically Relevant Toxicity Tests to Support Environmental Research and Risk Assessment, Olker, J. H., et al., Environmental Toxicology and Chemistry 41(6):1520–1539 (2022). Date checked: November 8, 2026.
• U.S. EPA ECOTOX Knowledgebase Public Portal and ASCII Data Distribution, U.S. Environmental Protection Agency (2026). Date checked: November 8, 2026.