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.

CAS numbers are unique numbers assigned to chemical substances by the Chemical Abstract Service to provide a consistent and reliable way of identifying the chemical substances.

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 Abstracts Service (CAS), a division of the American Chemical Society, assigns these identifiers to every chemical that has been described in the literature.

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 challenges and …

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

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