CAS REGISTRY®
CAS REGISTRY, the CAS substance collection, is the premier source relied upon by scientists, manufacturers, regulators, and data scientists worldwide for accurate information on chemical substances.
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What is a CAS Registry Number®?
Chemical compounds are described in many different ways including molecular formulas, chemical structures, generic, systematic, common, and trade names. This lack of clarity can cause frustration, delays, and even safety concerns.
A CAS Registry Number is a unique and unambiguous identifier for a specific substance that allows clear communication and, with the help of CAS scientists, links together all available data and research about that substance. Governmental agencies rely on CAS Registry Numbers for substance identification in regulatory applications because they are unique, easy validated, and internationally recognized.
Features
Authoritative source for accurate chemical names, structures, and CAS Registry Numbers®.
219 million organic substances, alloys, coordination compounds, minerals, mixtures, polymers, and salts disclosed in publications since the early 1800s.
~75 million protein and nucleic acid sequences.
Enriched with ~8 billion experimental and predicted property data points and spectra.
Updated daily with thousands of new substances to alert you to the most recent discoveries.
Linked to relevant publications, reactions, chemical suppliers, formulations, and more, as part of the CAS Content Collection™.
CAS REGISTRY and CAS Registry Number
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What is CAS REGISTRY?
What is a CAS Registry Number (CAS RN)?
What does a CAS Registry Number look like?
How does CAS assign Registry Numbers?
What kinds of compounds does the CAS REGISTRY contain?
Why have CAS Registry Numbers become the world standard?
Why do regulatory agencies rely on CAS Registry Numbers?
Where can I find CAS REGISTRY Numbers?
Why do some substances in CAS REGISTRY have zero references? How can I learn more about these substances?
How can I obtain or request assignment of a CAS Registry Number?
Why is it important to come to CAS for Registry Numbers?
What is the CAS RN Verified Partner Program?
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