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ShareA new paper published in Toxicological Sciences demonstrates the use of an in vitro human cell–based test method to assess two surfactants for their ability to cause point-of-contact respiratory tissue irritation.
The paper, titled “Human in vitro airway models to assess point-of-contact respiratory toxicity of surfactants and derive human equivalent concentrations after single dose exposure,” was co-authored by PETA Science Consortium International e.V., the US Environmental Protection Agency (US EPA), and the Flemish Institute for Technological Research (VITO). The study evaluated the respiratory tissue irritation potential of two surfactants, oleoyl sarcosine and Triton X-100, using a human bronchial epithelial cell line (BEAS-2B) and MucilAir, a reconstructed human respiratory epithelium (RHRE) manufactured by Switzerland-based Epithelix. The study found that the in vitro systems can be used to predict the respiratory effects of these surfactants and may be applicable to assess other chemical classes.
The method and data presented in this publication were recently used to inform guidance from the EPA that prioritises data from human cell–based methods and the use of these data to make regulatory decisions about surfactants. The Science Consortium continues to partner with the EPA to evaluate additional surfactants with this method to further build a robust data set.
Complementing this publication, the protocol used in the paper was also used to inform the study design of a multi-laboratory study evaluating the ability of MucilAir to predict respiratory tissue irritation following exposure to approximately twenty additional chemicals. Coordinated and funded by the Science Consortium, this collaborative study was carried out in laboratories in the United States, United Kingdom, Switzerland, and India. In August 2026, the project proposal was accepted into the work plan for the Organisation for Economic Co-operation and Development (OECD) Test Guidelines Programme (TGP). While additional testing, analysis, and documentation are still needed, the method is progressing through the formal process with the goal of eventually becoming an OECD Test Guideline. Because this method uses human cells, it avoids the need to extrapolate from rats to humans.
This work is part of a larger effort of the Science Consortium to build scientific confidence in in vitro inhalation toxicity methods. The Science Consortium published a paper in 2024 highlighting how fundamental differences in human and rat biology can limit the ability of animal tests to reliably predict human health effects following chemical exposure. And, in 2026, the Science Consortium co-authored a paper with the US EPA, the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods (NICEATM), and others demonstrating how RHRE models replicate key physiological characteristics of the respiratory tract, supporting their use as human-relevant models for respiratory toxicity testing.