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 …

Chemsrc provides fast access to over millions CAS#/CAS Number Database, including structure, MSDS, melting point, boiling point, density, etc.

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

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 …

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

Each number represents only one substance and has no chemical significance but serves solely as an internationally observed substance identifier by scientists, industry and regulatory organizations.

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

Dec 16, 2025 · 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.

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