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Defined Approaches to Testing and Assessment

A defined approach to testing and assessment relies on:

  • Input data generated from identified methods.
  • A data interpretation procedure, such as a machine-learning model, flowchart, or decision tree, through which the data are evaluated.

NICEATM, in collaboration with other scientists, has developed defined approaches for skin sensitization and endocrine disruption.

Defined Approaches for Skin Sensitization

On April 10, 2018, EPA released a draft Science Policy to reduce animal use by using defined approaches to identify potential skin sensitizers. The draft policy is the result of national and international collaboration among ICCVAM, NICEATM, Cosmetics Europe, EURL ECVAM, and Health Canada’s Pest Management Regulatory Agency. These collaborations included the following projects:

List of defined approaches for skin sensitization
Project Description Publication
Open-source tools to implement defined approaches to skin sensitization testing and assessment NICEATM and industry scientists from Cosmetics Europe wrote open-source code to reproduce defined approaches submitted to the OECD for skin sensitization testing and assessment. Data on 128 substances to evaluate these defined approaches were also developed as part of this project.
Defined approach using non-animal data to predict skin sensitization hazard

NICEATM and ICCVAM developed a defined approach that uses non-animal data to predict three skin sensitization endpoints:

  • Murine local lymph node assay (LLNA) hazard
  • Human skin sensitization hazard
  • Human or animal skin sensitization potency (enables classification of skin sensitizers as "weak" or "strong" without animal tests)
Open-source software to implement an integrated testing strategy based on a Bayesian network NICEATM and collaborators with Procter & Gamble developed open-source software to implement an integrated testing strategy (a type of defined approach) for skin sensitization potency based on a Bayesian network. The model provides the numerical probability for each of the four classes of potency that it uses.

Defined Approaches for Endocrine Disruption

List of defined approaches for endocrine disruption
Project Description Publication
Identification of substances with the potential to interact with the androgen receptor NICEATM and EPA developed a defined approach that combines data from 11 high-throughput screening tests with a computational model to identify substances with the potential to interact with androgen receptors in a cell. Androgens are a class of hormones, produced largely by the testes, that serve as the primary male hormones.
Identification of substances with the potential to interact with the estrogen receptor NICEATM validated a defined approach developed by the EPA that combines data from 18 high-throughput screening tests with a computational model to identify chemicals with the potential to interact with the estrogen receptors in a cell. Estrogens are a class of hormones, produced largely by the ovaries, that serve as the primary female hormones.