Traditional testing methods to identify substances that cause allergic contact dermatitis use
animals, but concerns about testing efficiency and animal welfare are driving efforts to replace
traditional testing methods with non-animal methods. In practice, it usually takes several
non-animal tests to provide the same level of information as single animal test. NICEATM is working
with other NTP scientists and industry experts to create an integrated testing strategy to combine
information from multiple testing methods to identify potential skin sensitizers.
NICEATM is collaborating with Dr. Joanna Jaworska and colleagues at Procter and Gamble, who have
developed an integrated testing strategy for identifying potential skin sensitizers without
conducting animal tests. The testing strategy uses a Bayesian network to analyze data from
non-animal tests and other information about a test substance, such as chemical structure and
solubility, to identify potential skin sensitizers. The analysis considers all the available
relevant information about a substance and produces a numerical probability that the substance is a
sensitizer. This probability could potentially be used to make decisions about whether substances
require hazard labeling, without requiring animal testing.
More information about the testing strategy can be found in the following publications:
- Jaworska et al. 2011.
Integrating non-animal test information into an adaptive testing strategy — skin sensitization proof of concept case. ALTEX 28:211-225.
- Jaworska et al. 2013.
Bayesian integrated testing strategy to assess skin sensitization potency: from theory to practice. J Appl Toxicol 33:1353-1364.
The software used by Procter and Gamble for these analyses is patented, so Jaworska and the NTP scientists are collaborating to develop similar tools using free, publically available software to make the integrated testing strategy approach more widely available. The goal is to allow organizations worldwide to use this approach for identifying potential sensitizers and support the effort towards eliminating animal testing in this area.
A link to a script that uses the R programming language to run the integrated testing strategy analysis will be available on the NTP website soon. NICEATM and NTP scientists are also collaborating with Jaworska and colleagues on an improved version of the integrated testing strategy that will be published in the scientific literature.