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MAHWAH, N.J., June 26, 2026 — The Research Institute for Fragrance Materials (RIFM) will showcase advances in read-across, chemical grouping, and non-animal safety assessment at the European Society of Toxicology In Vitro (ESTIV) 2026 Congress, taking place June 29 through July 2 in Maastricht, the Netherlands. 

Holger Moustakas, PhD, Senior Scientist, Chemistry & Genotoxicity at RIFM, will contribute to the meeting through two scientific poster presentations and as both a speaker and facilitator during the International Collaboration on Cosmetics Safety (ICCS) Best Practice Guidance Workshop: Application of Read-Across in Cosmetic Safety Assessment. 

Collectively, these presentations highlight practical approaches that improve the scientific rigor, transparency, and reproducibility of modern safety assessment while supporting the continued advancement of New Approach Methodologies (NAMs). 

Advancing chemical grouping for read-across 

On June 29, Dr. Moustakas will present “Advancing Chemical Grouping: Development and Application of Signature-Based Structure-Activity Groups for Non-Animal Safety Assessments.” 

The work describes the development of Structural Activity Groups (SAGs), a robust and reproducible approach for organizing thousands of chemicals into scientifically meaningful groups based on shared structural characteristics. These groups can be applied to prioritize testing, support read-across, and strengthen predictive toxicology without relying on new animal studies. 

Improving the safety assessment of natural complex substances 

On June 30, Dr. Moustakas will present “Chemical Clustering of Natural Complex Substance (NCS) Materials: A Hierarchical Clustering Approach for Use in Non-Animal Safety Assessments.” 

The research demonstrates how agglomerative hierarchical clustering can be used to group 166 natural complex substances representing more than 20 botanical families and over 30 genera. Rather than relying solely on botanical origin, the approach identifies scientifically meaningful groupings based on composition, creating a stronger foundation for read-across and more efficient safety assessments of complex natural mixtures. 

Helping scientists apply read-across with confidence 

Following the congress, Dr. Moustakas will serve as an invited speaker and breakout facilitator during the ICCS Best Practice Guidance Workshop. 

His presentation, “A Deep-Dive into Analogue Selection and Evaluation,” will examine how appropriate analogues are identified using structural similarity, shared functional groups, physicochemical properties, chemical reactivity, structural similarity thresholds, and matched molecular pairing. The session will outline a structured, stepwise framework for analogue identification, screening, and evaluation before participants apply these concepts during an interactive case study on systemic toxicity. 

As a breakout facilitator, Dr. Moustakas will help guide safety assessors and regulatory scientists through practical application of the ICCS Best Practice Guidance, reinforcing consistency, transparency, and scientific confidence in read-across decision-making. 

“The future of safety assessment depends on making the best possible use of existing scientific data,” Dr. Moustakas explained. “Whether we’re developing better ways to group chemicals, evaluating complex natural substances, or strengthening analogue selection, our goal is the same: to provide scientifically robust methods that improve confidence in read-across while reducing the need for additional animal testing.” 

Dr. Anne Marie Api, PhD, Fellow ATS, President of RIFM, explained that the organization’s participation reflects its longstanding commitment to advancing internationally recognized scientific methods. 

“Scientific progress depends on collaboration and transparency,” Dr. Api said. “ESTIV brings together many of the world’s leading experts in alternative toxicology and New Approach Methodologies. Sharing RIFM’s research in this forum helps advance the science that supports more human-relevant, scientifically robust safety assessments while contributing to global efforts to reduce reliance on animal testing.” 

RIFM’s contributions at ESTIV 2026 reflect the Institute’s continued investment in developing practical scientific tools that enable better use of existing data, improve regulatory confidence, and accelerate modern, exposure-led approaches to chemical safety assessment.