DTSS Webinar
Title: In Vitro Testing and NAM-Based Approaches for Safety Assessment: Applications in Skin Sensitization and Quantitative Risk Assessment
Date and Time: Wednesday, July 29, 2026, 11:00 AM to 12:15 PM (US EDT, UTC –4)
Hosted by: SOT Dermal Toxicology Specialty Section
Join us as Dr. Hervé Groux (ImmunoSearch) and Dr. Isabelle Lee (Research Institute for Fragrance Materials) present their work on NAMs and in vitro testing in the field of skin sensitization assessment.
Registration required for this free webinar.
Speaker(s):
Hervé Groux, DVM, PhD, CEO and CSO, ImmunoSearch
The assessment of skin sensitization potential in complex mixtures, such as cosmetic products and medical device extracts, presents distinct scientific and regulatory challenges. While validated in vitro methods have significantly advanced for individual substances, their application to mixtures requires careful consideration of formulation effects, irritancy, and potential chemical interactions.
The SENS-IS assay, based on a transcriptomic approach using reconstructed human epidermis, offers a robust tool for addressing these complexities. A catch-up study supporting the use of a newly developed in-house 3D epidermis model is currently under evaluation by the OECD, further reinforcing the assay's relevance for regulatory use. Our published work (2019) demonstrated that SENS-IS can identify a variety of mixture-related effects, including vehicle-dependent modulation of sensitization potency, irritant-induced enhancement, additive or synergistic interactions at low concentrations, and positive responses in finished consumer products. Since then, the assay has been applied to a wide range of mixtures, supporting its applicability across different regulatory contexts.
This presentation will focus on recent case studies involving cosmetic products, illustrating how formulation components can significantly influence the sensitization profile of active substances. To expand the assay’s relevance, we are also evaluating a complementary full-thickness skin model that incorporates a dermal compartment. This system more closely mimics native skin architecture and offers new insights into mixture effects involving deeper skin layers. Together, the epidermal and full-thickness models enhance the utility of the SENS-IS assay in mixture testing, contributing valuable data for risk assessment
Isabelle Lee, PhD, Manager, Human Health Safety & Strategy, Research Institute for Fragrance Materials
Quantitative risk assessment (QRA) for dermal sensitization is critical in establishing safe use levels of sensitizing ingredients in consumer products. Traditionally, QRA relies on the No Expected Sensitization Induction Level (NESIL) as the point of departure (PoD), often determined through human testing via the Confirmation of No Induction in Humans (CNIH) repeat patch test. However, with the advancement of New Approach Methodologies (NAMs) and their integration into Next Generation Risk Assessment (NGRA) frameworks, industry is moving toward not only non-animal, but also non-human testing strategies for PoD derivation.
Significant progress has been made in applying NAMs to discrete chemicals, but challenges remain in evaluating natural complex substances (NCS) and other mixtures due to their multiconstituent and variable nature. In the fragrance industry, many NCS contain known discrete components, enabling a component-based risk assessment approach. However, this strategy is not universally applicable, prompting exploration of NAM-based methods for direct PoD derivation.
This presentation highlights the use of several quantitative potency-based NAMs, which may include Bayesian models like SARA and SARA-ICE, the GARDskin dose-response assay, and OECD in vitro regression models, to support risk assessment of NCS and mixtures. Within the NGRA framework, these methods allow for the derivation of a NAM-based PoD, which can be adjusted using uncertainty factors to estimate a predicted NESIL (pNESIL). This value is then used to calculate Acceptable Exposure Levels (AELs) for consumer products such as deodorants and bar soaps, which are compared against estimated Consumer Exposure Levels (CELs) to determine the margin of safety. Case studies will be presented to demonstrate how currently available NAMs can be effectively used in NGRA to assess NCS, offering a scientifically robust alternative to traditional animal and human testing for QRA.
Registration required for this free webinar.
Past Webinars
2026 Joint DTSS and IVAMSS Webinar: Dermal Toxicity Assessment Using In Vitro Methods: Plant Extract Case Study and ICCS Best Practice Guidance for Skin Sensitization
Thursday, May 28, 2026
Hosted by: The SOT Dermal Toxicology & In Vitro and Alternative Methods Specialty Sections
Presentations:
Comprehensive In Vitro Safety Assessment of Acorus calamus Rhizome Oil Using OECD-Compliant New Approach Methods: Classification as a GHS Category 1B Sensitizer and Category 2 Irritant
Karishma R. Desai, Senior Research Officer, Jai Research Foundation, India
From Data to Decisions: The ICCS Best Practice Guidance on Skin Sensitization
Donna Macmillan, PhD, Director of Outreach and Capacity Building, International Collaboration on Cosmetics Safety
Materials:
Webinar Recording and Materials
2025 Dermal Toxicology Webinar: Explore the Future of Skin Toxicology and Risk Assessment—Recognizing the 2024 DTSS Paper of the Year Award Recipients.
October 15, 2025
Hosted by: The SOT Dermal Toxicology (DTSS) Specialty Section
Speaker(s):
Nancy Hopf, PhD, Unisanté, Center for Primary Care & Public Health, University of Lausanne, Switzerland
Hans Raabe, MS, Institute for In Vitro Sciences, Gaithersburg, MD, USA
Materials:
Webinar Recording and Materials
2025 Joint DTSS and SCCT Webinar: Recycled, But Safe? Tackling Contaminants in Sustainable Packaging for Cosmetics & Personal Care.
June 2, 2025
Hosted by: The SOT Sustainable Chemicals through Contemporary Toxicology (SCCT) and Dermal Toxicology (DTSS) Specialty Sections
Speaker(s):
Ramez Labib, PhD, MBA, DABT, ERT, Venebio Group, LLC
Gerald Renner, PhD, Cosmetics Europe
Brandon Reid, MPH, Cradle to Cradle Products Innovation Institute
Materials:
Webinar Recording and Materials
2024 Dermal Toxicology Specialty Section Webinar: A Comparative Study of the In Vitro Dermal Absorption of Radiolabeled Benzophenone Through Human Skin.
October 23, 2024
Hosted by: The SOT Dermal Toxicology Specialty Section
Speaker(s):
Clive Roper, BSc, PhD, CBiol, CSci, ERT, FRSB, Director, Roper Toxicology Consulting Ltd.
Sadaff Ejaz, PhD, Principal Scientist, Kenvue
Materials:
Webinar Recording and Materials
2022 Dermal Toxicology Specialty Section Webinar: International Advances in Alternatives and a Next Generation Risk Assessment Case Study for Skin Allergy.
April 19, 2022
Speaker(s):
Nicole Kleinstreuer, NIEHS/NICEATM
Georgia Reynolds, Unilever
Abstract:
Coordinated global efforts over the last several decades have resulted in the development and adoption of alternatives to traditional animal tests for dermal hypersensitivity assessment. Following the adverse outcome pathway (AOP) framework, several new approach methodologies (NAMs) mapped to key molecular and cellular events in the AOP have been validated and combined to yield “defined approaches,” which were shown to provide superior performance to the existing animal tests when compared to human data for hazard and potency categorization. However, regulatory and industry needs extend beyond classification to deriving points of departure that will facilitate quantitative risk assessment. Next Generation Risk Assessment (NGRA) is an exposure-led, hypothesis-driven approach which integrates NAMs. This hypothetical skin allergy risk assessment case study of two consumer product exposures—0.1% coumarin in a face cream and 1% coumarin in a deodorant—demonstrates the application of a skin allergy NGRA framework which incorporates the Skin Allergy Risk Assessment (SARA) Model. The SARA Model is a Bayesian approach which allows prediction of a human relevant point of departure (PoD) (the HRIPT dose with a 1% chance of sensitisation or ED01 [µg cm-2]) based upon any combination of HRIPT, LLNA, DPRA, KeratinoSens, h-CLAT or U-SENS data. Through incorporation of benchmark exposure information, the SARA Model can be used to calculate a risk metric for a consumer relevant exposure. This case study demonstrates how integrating a computational model and NAM data in a weight of evidence can build confidence in robust decision making.
Materials:
Watch the Recording
Nicole Kleinstreuer Presentation |
Georgia Reynolds Presentation
Title: Dermal Absorption and Toxicology In Vitro: What are the Tests, How Can We Use Them and Where are the Innovations?
Tuesday, February 1, 2022
Speaker(s):
Clive Roper, PhD, Director, Roper Toxicology Consulting Limited
An overview of the state of the science in vitro approaches for dermal absorption and dermal toxicology assessment will be provided by a thought leader in the field.
Abstract:
Dermal absorption and toxicology in vitro; what are the tests, how can we use them and where are the innovations? Some of the earliest toxicology tests were developed to identify topical hazards (e.g., the Dermal Draize test and the Guinea Pig Maximisation test). There have been many years of development of new assays to create more human relevant data. For example, skin absorption has been evaluated in the human skin since the 1960s using the Franz diffusion cell resulting in regulatory acceptance by FDA, EPA, and the European Agencies, particularly after the creation of the OECD 428 in 2004. There has been a plethora of dermal toxicology tests developed to identify acute toxicity outcomes such as using the EpiDerm 3D model for skin irritation (OECD 439) and corrosion (OECD 431) to replace the Draize irritation tests or the 3T3-NRU (OECD 432) to screen and often replace phototoxicity testing. The road to replacement of the skin sensitization animal tests (including the LLNA) has been slower due to the complexity of this disease to model. However, in 2021, a defined approach for skin sensitization was published (OCED 497) and this identifies the different testing required including the DPRA, KeratinoSens™, h-CLAT assays. This seems to have resolved the acute testing needs, but where can there be further innovation? The skin irritation test (OECD 439) is only suitable for chemicals and not formulations and mixtures and is of particular interest for resolution by US EPA. What about more chronic questions? The skin absorption test (OECD 428) has been extensively used for 24 h, but the rat in vivo test is used up to 168 h, can this in vitro test system be used for longer time periods in regulatory toxicology? How can further innovations take place against the concerns about the lack of human relevance of the current animal tests?
Materials:
Watch the Recording
Clive Roper Presentation