High-Throughput Toxicology

For most chemicals, data and information to assess the potential toxicity to humans and other species is limited or incomplete. The large number of existing chemicals and the manufacturing of new chemicals has increased the need for rapid chemical assessments. High-Throughput Toxicology (HTT) research develops and applies New Approach Methods to reduce the use of animals for testing thousands of chemicals such as Chemicals of Immediate and Emerging Concern (e.g., per- and polyfluoroalkyl chemicals) and chemical mixtures.

• Research Efforts
• Tools and Resources 
• Helpful Definitions

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Research Efforts

View Recent Publications

Tiered toxicity testing strategies

HTT data is used to inform tiered toxicity testing strategies which us high-throughput approaches to screen chemicals for potential hazards and prioritizes chemicals for subsequent testing using more traditional methods.

• ToxCast (Toxicity Forecaster)
• Toxicology Testing in the 21^st Century: Federal Agency consortium that is using high-throughput robotic screening to test approximately 10,000 environmental chemicals and approved drugs for their potential to disrupt biological pathways that may result in toxicity.
• High-Throughput Transcriptomics and High-Throughput Phenotypic Profiling: EPA scientists are using high-throughput transcriptomics (HTTr) and high-throughput phenotypic profiling (HTPP) methods to characterize the biological activity of chemicals.

Priority toxicological endpoints

In Agency risk assessments, a number of priority endpoints characterize the potential hazard of a chemical. HTT rapidly generates chemical hazard data on specific endpoints of interest such as developmental neurotoxicology, toxicological effects from inhalation exposure, and other priority endpoints. HTT helps prioritize, screen, and evaluate chemical safety for thousands of chemicals while reducing reliance on animals used for traditional toxicity tests.

• Endocrine Disruption Research
• Developmental Neurotoxicity Research

Contaminants of Immediate and Emerging Concern (CIECs)

Contaminants of immediate and emerging concern include chemical substances that may cause ecological or human health impacts and are either new or existing contaminants of increased priority.

EPA's Safer Chemicals Researchers are using high throughput toxicology, including high throughput phenotypic profiling and high throughput transcriptomics, to test hundreds of Per- and polyfluoroalkyl substances (PFAS) for potential toxicity. Traditional approaches to generate toxicity information are resource intensive, so researchers are using new approach methods (NAMs), including in vitro high-throughput toxicity testing and toxicokinetic testing, to inform PFAS hazard characterization and further testing.

• Per- and Polyfluoroalkyl Substances (PFAS)

  Tools and Resources

• CompTox Chemicals Dashboard: Provides data and information for thousands of chemicals, including contaminants of immediate and emerging concern such as PFAS and lead.
• Recent HTT Publications and Research
• New Approach Methods (NAMs) Work Plan
• PFAS Strategic Roadmap
• National PFAS Testing Strategy
• Endocrine Disruptor Screening Program (EDSP): Aims to use computational models and high-throughput screening assays to prioritize and screen chemicals to determine their potential to interact with the estrogen, androgen or thyroid bioactivity.
• ToxCast (Toxicity Forecaster): Uses rapid chemical screening technologies (called "high-throughput screening assays") to limit the number of required laboratory animal-based toxicity tests while quickly and efficiently screening thousands of chemicals for potential human and environmental effects.