New online database to improve environmental risk assessment of chemicals and avoid animal testing

The EnviroTox database is an international project, led by the Health and Environmental Sciences Institute and involving the JRC. This public database of ecotoxicological data brings together more than 91,000 curated records for more than 4000 chemicals across 1500 species. The case study published by Connors et al. demonstrated that eco-TTC values can facilitate a screening level mixture assessment if data are missing for a limited number of chemicals, which could replace the need for additional animal testing.


Environmental risk assessment of chemicals typically requires toxicity data for fish, algae and crustaceans. The need for rapid and predictive methods to address ecological hazards of diverse substances is essential because the chemical universe remains largely untested. Flexible approaches that do not require the use of large numbers of vertebrate test animals (fish, amphibians, birds, etc.) are needed to address broad animal welfare concerns as well as optimize resource use. To appropriately develop robust new approach methodologies and nontesting approaches, existing information must be made available via integrated and curated data sets.


A pragmatic and scientifically credible way of filling data gaps is to assign chemicals to groups and examine the distribution of toxicological effects across chemicals in the group. The groups can be composed in various ways, for example based on species, chemical class or mode of toxicological action. Since the chemicals within each group usually have a range of toxic potencies, the most toxic values can be used to derive a safe concentration, known as the ecological Threshold of Toxicological Concern (eco-TTC) The ecoTTC approach can be used to fill data gaps while reducing the need for additional animal testing. The TTC concept is well established for assessing human safety of indirect food-contact substances and has been reapplied for a variety of endpoints including carcinogenicity, teratogenicity, and reproductive toxicity. The TTC has benefits for screening level risk assessments, including the potential for rapid decision-making, fully utilizing existing knowledge, reasonable conservativeness for chemicals used in lower volumes, and reduction or elimination of unnecessary animal tests. A curated and archived data set has been compiled for the initial purposes of developing ecoTTCs and CTDs as screening tools for chemical hazard assessment. Clearly, such a database can be useful for a wide range of purposes where management of environmental hazard data is required. This new database, EnviroTox, is accessible at, and it is planned that the database will be updated on a yearly basis.


Flexible, rapid, and predictive approaches that do not require the use of large numbers of vertebrate test animals are essential, as the chemical universe remains largely untested. Development of robust new approach methodologies (NAMs) and non-testing approaches requires availability of existing information via curated, integrated datasets. The ecological threshold of toxicological concern (eco-TTC) represents one such NAM approach that can identify a conservative, de minimis toxicity value for chemicals with little or no information available. A large, diverse dataset was developed from a range of sources, with harmonization and characterization steps to ensure that the information could be effectively organized and mined. The resulting EnviroTox database ( contains 91,217 aquatic toxicity records representing 1,563 species, and 4,016 unique chemical CAS. Chemical-specific information is also linked to each record and includes physical chemical information, chemical descriptors, and mode of action classifications. Toxicity data is associated with the physical chemistry data, mode of action classifications, and curated taxonomic information for the organisms tested. The EnviroTox platform also includes three analysis tools: a predicted no effect concentration (PNEC) calculator, and eco-TTC distribution tool, and a chemical toxicity distribution (CTD) tool. Although the EnviroTox database and tools were originally developed to support eco-TTC analysis and development, it has broader applicability to the field of ecological risk assessment.

Source: Connors et al. Creation of a Curated Aquatic Toxicology Database: EnviroTox. Environmental Toxicology and Chemistry. Vol 39 (5), February 4 2019.