CAS Content at a Glance

CAS maintains counts of its database records to reflect their scope of coverage and to ensure that researchers have confidence in their comprehensiveness.


Chemical Substances
Regulated chemicals
Chemical suppliers
Chemical Industry Notes
Number of


How do we count

  • >47 million records


How do we count

  • >106 million reactions (>90 million single- and multi-step reactions and >14.2 million synthetic preparations)


How we count

  • >388,000 inventoried or regulated chemicals


How do we count

  • Millions of commercially available products
  • Millions of unique CAS Registry Numbers


How do we count


  • >1.7 million records


How do we count




  • >1.1 million searchable Markush structures
  • >500,000 patent records


How do we count


Information about the many different types of substances, including

  • Synonyms
  • Molecular formulas  
  • Ring analysis data
  • Structure diagrams
  • Experimental and predicted property data
  • Literature references

Chemistry and chemistry-related articles covering
topics such as

  • Proteomics
  • Genomics
  • Biochemistry
  • Biochemical genetics
  • Organic
  • Macromolecular
  • Applied
  • Physical, inorganic, analytical

Reaction information consisting of

  • Structure diagrams for reactants and products
  • CAS Registry Numbers for all reactants, products, reagents, solvents, and catalysts
  • Detailed reaction conditions
  • Experimental procedures

    Chemical substances that are regulated in key markets across the globe

    • Chemical names
    • Synonyms
    • Regulatory lists
    • Chemical inventory status

      Information about commercially available chemicals and their suppliers:

      • CAS Registry Number 
      • Supplier information
      • Quantities
      • Prices

      Chemical industry trade publications including

      • Abstracts
      • Bibliographic information
      • CAS Registry Numbers
      • Chemical names
      Markush structures of organic or organometallic molecules are searchable. Patent reference information is displayable.
      • Substances from journal articles, patents, chemical catalogs, and reputable web sources from the early 1800s to present  
      • GenBank sequences
      • Organic substances as well as
        - Alloys
        - Coordination
        - Minerals
        - Mixtures
        - Polymers
        - Salts
        - Sequences
        - Organo-
        - Proteins
        - Inorganic
      • Early 1800s to present 
      • Chemistry indexed from more than 50,000* scientific journals worldwide, with thousands of active titles currently covered
      • Rapid analysis of more than 1,500 key chemical journals
      • Patents from 63 patent authorities (see CAS Coverage of Patents)
      • Conference proceedings
      • Technical reports
      • Books
      • Dissertations
      • Reviews
      • Meeting abstracts
      • Electronic-only journals
      • Web preprints
      • 1840 to present
      • Reactions from journals, patents, and dissertations, as well as from evaluated reference works
      • 1980 to present
      • Originally from data in the 1985 TSCA inventory and supplements
      • U.S. Government Federal Register
      • International chemical regulations
      • 16 national and international inventories
      • State lists (view lists)
      • Hundreds of suppliers for commercial chemicals worldwide
      • Chemical catalogs
      • 1974 to present
      • Worldwide chemical business needs
      • Government publications
      • Journals
      • Newsletters
      • Special reports
      • Trade magazines
      • 1961 to present
      • Markush structure records for patents in CAplus from 1988 to present with selected coverage of English (1984-1987), French and German (1986-1987) and Japanese (1987)  patents, including coverage of Russian patents after January 10, 2000 and Korean patents from 2008 to present
      • INPI data from 1961-1987
      Update Frequency Daily Daily  Daily Weekly Weekly Weekly Daily


      *From 1907 to present, CAS has indexed chemistry from more than 50,000 journal titles. In that time, publishers have discontinued, merged, split, revised and changed the focus of many titles.