CAS REGISTRY®, the CAS substance collection, is the premier source relied upon by scientists and regulators worldwide for accurate information on chemical substances.

CAS Registry Numbers (CAS RN) are simple and regular, convenient for database searches. They offer a reliable, common and international link to every specific substance across the various …

Quickly confirm chemical names, CAS Registry Numbers®, structures or basic physical properties by searching compounds of general interest or leveraging an API connection.

Look up CAS in Wiktionary, the free dictionary. CAS, CaS, or cas may refer to:

Feb 11, 2026 · CAS provides solutions and services that help empower scientific discoveries. Learn how CAS can facilitate your research and drive innovation.

Feb 11, 2026 · CAS builds the world’s largest collection of human-curated scientific knowledge covering over 150 years of published science. Our tools are designed to address the challenges and …

Access the world’s most comprehensive chemical substance and reaction data. Search by structure, name, CAS Registry Number®, or spectra data. Uncover relevant literature, patents, and regulatory …

CAS content covers all disclosed chemistry and related science from thousands of journals and 109 patent authorities, as well as reputable Web sources, dissertations, books, conference proceedings, …

Covering advances in chemistry and related sciences over the last 150 years, the CAS Content Collection empowers researchers, business leaders, and information professionals around the world …

Access current, accurate chemical substance information powered by a comprehensive database.