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

CAS (Chemical Abstracts Service) is a division of the American Chemical Society. It is a source of chemical information and is located in Columbus, Ohio, United States.

CAS registry numbers are copyrighted by the American Chemical Society. Redistribution rights for CAS registry numbers are reserved by the American Chemical Society.

ChemSrc offers quick search by Name, CAS No., Formula, SMILES, InChIKey, or EINECS. Access professional data for millions of compounds, including Physical & Chemical Properties, …

Dec 22, 2025 · 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 …

A CAS Registry Number[1] (also referred to as CAS RN[2] or informally CAS Number) is a unique identification number, assigned by the Chemical Abstracts Service (CAS) in the US to every …

CAS provides solutions and services that help empower scientific discoveries. Learn how CAS can facilitate your research and drive innovation.

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 …

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

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