Inflammatory Cytokine Expression

Many manufacturers of personal care and cosmetic products expect (along with their customers) that their products will not irritate the skin. Unfortunately, many ingredients (e.g. surfactants, preservatives, emulsifiers and many other organic substances) have an inherent irritating property. Although other in vitro assays can predict irritancy vs. non-irritancy for purposes of regulatory compliance, many of these manufacturers need to differentiate between moderately irritating substances and those which are much milder. Some examples are: baby products, moisturizers or other products used in or near sensitive areas of the body.

In order to provide our clients with a service that resolves non-, minimal- and mild-irritants, we developed the mildness assay.

By combining the release of cytokines with the standard irritation assay, we are able to provide our clients with information on whether the product is expected to irritate the epidermis and to what degree.

Note: This assay is not designed to evaluate strongly irritating or corrosive substances.

Product Safety Assessment Using an In Vitro Test System Based on Viability of, and Cytokine Released by, Reconstructed Human Epidermis (RhE) Models

  • Assay used for the evaluation of the skin irritation potential of topically administered test materials.
  • Frequently used to address the irritation profile of (but not limited to) surfactant-based formulations with rinse-off applications.
  • The assay allows ranking of test materials with anticipated low irritation potential using pro-inflammatory cytokine analyses such as interleukin IL-1α.

Assay Endpoints

  • Tissue viability.
  • Cytokine expression.

Applicability Domain

  • Ingredients of finished products formulated to have low irritation potential.
  • Undiluted (leave-on intended use) or diluted (rinse-off intended use) materials.


  • Ranking of test materials’ irritation potential.
  • Qualification of benchmark materials.
  • Correlation with clinical data

For more information, please contact IIVS.