CAS REGISTRY - The gold standard for chemical substance information

CAS REGISTRY® contains more than 181 million unique organic and inorganic chemical substances, such as alloys, coordination compounds, minerals, mixtures, polymers and salts, and more than 68 million protein and DNA sequences - more than any other database of its kind.

CAS Registry Number® is universally recognized and used to provide a unique, unmistakable identifier for chemical substances.


CAS Registry Number® Assignment and Substance Identification

Expert CAS scientists are available to assign CAS Registry Numbers and CA Index Names.

  • Inventory Expert Service (IES) for obtaining CA Index Names and CAS Registry Numbers for EPA TSCA PMN submissions.
  • Chemist Consultation for CAS Registry Numbers or substance information for reports, proprietary files, or confirmation for an International Nonproprietary Name (INN), or United States Adopted Name (USAN) application
  • Registry Lookup - for a simple exact match of a chemical name or CAS Registry Number

Note: If your organization uses CAS Registry Numbers to help others locate accurate chemical information, please refer to the CAS RN Verified Partner Program information to ensure appropriate licensing and use.

 Use CAS REGISTRY to locate

  • literature references to the substance
  • experimental and predicted property data (boiling and melting points, etc.)
  • CA Index Names and synonyms
  • commercial availability
  • preparative methods
  • spectra
  • regulatory information from international sources

You can obtain the information you need for millions of substances from the most current and reliable collection of chemical substance information in the world, CAS REGISTRY.

CAS Registry Content

  • Substances reported in the literature back to the early 1800s.
  • Updated daily
  • Substance information enriched with experimental and predicted property data, including  ~8 billion property values, data tags and spectra

All substance records contain a unique CAS Registry Number. Records may also have CA index names, synonyms, structure diagrams, stereochemistry, molecular formulas, ring data, alloy composition tables, protein and nucleic acid sequences, classes for polymers, and the number of references in the CA/CAplus databases. All of this information is displayable and searchable on STN, but some of it is only displayable in SciFinder and SciFindern.

In addition to substance information, REGISTRY records contain super roles and document type information from the CAplus database.

Sample record from SciFindern

Lisinopril structure from SciFinder-n


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