Dermal Sensitization Risk Assessment

With a dramatic increase in the development of wearable consumer electronic products, there is an increased likelihood that irritating or sensitizing chemicals are transferred from the product to the user skin. These chemicals can potentially trigger irritation contact dermatitis (ICD) or more importantly, allergic contact dermatitis (ACD) reactions. ICD is non-immunological reaction that manifests as a localized inflammation of the skin caused by direct damage following acute exposure to a chemical irritant. ACD is an inflammation of the skin caused by an immunologic “delayed hypersensitivity” reaction triggered by repeated or chronic exposure to chemical sensitizer. The need to consider dermal reactions from these new products, and other products that involve similarly sustained dermal contact, has been reinforced by recent news reports of adverse skin reactions.

Exponent scientists have unique tools and experience to assist with prerelease testing and risk assessment of wearable products or to identify chemical and materials in products responsible for consumer dermal reactions.

Product Testing

  • Leaching tests using a modified EN 1811 process with artificial sweat are used to assess chemical transfer from the products to skin under “aggressive immersion” contact conditions.
  • Simulated handling tests using artificial sweat dampened wipes are used to assess chemical transfer under less aggressive contact conditions.

Assessing Exposure and ACD-Elicitation Risk

  • Dermal exposure (dose or “load”) is estimated for each leached chemical of concern from product biocompatibility tests and product-use scenarios.
  • Quantitative assessment of ACD-elicitation risks posed by electronic wearables provides a way to anticipate and characterize potential liability associated with consumer use of existing products, or with alternative product designs during product development, in a product class to which little regulatory guidance and few standards currently apply.
  • Exponent scientists have developed a quantitative model that estimates the percent of a sensitized user population expected to experience ACD-elicitation reaction after exposure to one or more sensitizing chemicals transferred from an electronic wearable or similar product. This risk assessment model is unique and not available elsewhere.

Recent Related Presentations and Publications

Bogen KT, Garry MR. Risks of allergic contact dermatitis elicited by nickel, chromium, and organic sensitizers: Quantitative models based on clinical patch test data. Risk Anal 2017 (in press). doi: 10.1111/risa.12902. 

Sheehan P, Bogen KT, Singhal A, Kalmes R, Robert M, Fedoruk MJ. Wearable products and allergic contact dermatitis: a new risk assessment challenge. Presented at the 54th Annual Meeting of the Society of Toxicology, San Diego, CA, March 22-26, 2015.

Sheehan P, Cooper M, McNulty J, White K. Wearable technology – Trends, design & risk considerations. Presented at the SFAI Thought Leadership Webinar. Sports Fitness Industry Association. November 18, 2014.

Figure 1. Exponent approach to estimating product-specific dermal exposure.