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 …

“CAS registry” is a registered trademark of the American Chemical society.

Search and explore chemical information in the world's largest free chemistry database. Search chemicals by name, molecular formula, structure, and other identifiers. Find chemical and physical …

Chemical products are described in many different ways including chemical structures, generic, molecular formulas, systematic, common, and trade names.

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

Jan 13, 2026 · You can also identify your substance of interest by its CAS Registry Number®, which is universally used to provide a unique, unmistakable identifier for chemical substances.

Feb 4, 2026 · The CAS reference collection aggregates and connects scientific knowledge from thousands of journals and other sources published globally in more than 50 languages dating back to …

Oct 8, 2024 · What is a CAS Number? A CAS number is a unique identifier assigned to every chemical substance described in the open scientific literature. This number, typically comprising up to ten …

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.