Saimah Khan2026-08-252025979-8-89695-407-1http://136.232.12.194:4000/handle/123456789/2108TOKYO 11 TH INTERNATIONAL INNOVATIVE STUDIES & CONTEMPORARY SCIENTIFIC RESEARCH CONGRESS April 6-7 2026 / Tokyo - Japan CONGRESS PROCEEDINGS BOOK EDITORS Dr. Duong To Quoc THAI Dr. Esra KOÇAKPer- and polyfluoroalkyl substances (PFAS) are a large class of synthetic fluorinated chemicals increasingly recognized as persistent environmental and human contaminants (EPA, 2023; Peaslee et al., 2021). PFAS are intentionally added to many cosmetic and personal care products to enhance spreadability, water resistance, film formation, and long-lasting performance, and may also enter formulations unintentionally as impurities or degradation products of precursor ingredients (FDA, 2025; ToxStrategies, 2025). Recent analytical surveys report that a substantial proportion of foundations, mascaras, lipsticks, and other colour cosmetics sold in North America and Europe contain high levels of fluorine, suggesting widespread PFAS use (Peaslee et al., 2021; University of Notre Dame, 2024). While cosmetics are not the dominant source of aggregate PFAS exposure, their direct, frequent application to skin, lips, and peri-ocular areas raises concern, particularly for long-lasting and waterproof products marketed for daily use (Exponent, 2026; Wigle et al., 2025). Multiple epidemiological and toxicological studies link certain well-studied PFAS (for example, PFOA and PFOS) to kidney and testicular cancers, immune suppression, endocrine disruption, dyslipidaemia, and developmental toxicity, although cosmetic-specific risk assessments remain limited and uncertain (WHO, 2022; ECHA, 2023).en-USNATURAL SCIENCES::ChemistryBook chapter