CAS Content

The World's Largest Collection of Chemistry Insights

Every day CAS scientists collect and analyze published scientific literature from around the globe, building the highest quality and most up-to-date collection of scientific information in the world.

Covering advances in chemistry and related sciences over the last 150 years, the CAS Content Collection empowers researchers, business leaders, and information professionals around the world with immediate access to the reliable information they need to fuel innovation.

Human intelligence is at the heart of the CAS Content Collection. Our team of scientific analysts embodies a wealth of specialized knowledge that lets them accurately extract and verify a multitude of data and key insights from each publication, making connections and uncovering trends only possible with the combined power of expert human analysis and advanced data technology.

CAS COVID-19 Resources

Aligned with our mission as a division of the American Chemical Society, CAS is making a wide range of resources and expertise openly available to support research related to COVID-19. (see other open access content)


As the authoritative source for chemical names, structures, and CAS Registry Numbers®, the CAS substance collection, CAS REGISTRY®, serves as a universal standard for chemists worldwide.

  • 204 million organic and inorganic substances disclosed in literature since the early 1800s
  • Includes alloys, coordination compounds, minerals, mixtures, polymers, and salts
  • 69 million protein and nucleic acid sequences
  • Enriched with experimental and predicted property data and spectra
  • Updated daily

CAS References

Details from thousands of global scientific references are added to the CAS Content Collection every day creating a comprehensive resource to access and keep up to date on the world’s published scientific literature across disciplines including biomedical sciences, chemistry, engineering, materials science, agricultural science, and many more.

  • Sourced from thousands of journals and 64 patent authorities as well as technical reports, books, conference proceedings, and dissertations published globally
  • More than 59 million records from publications dating back to the early 1800s, with continuous coverage since 1907
  • English language summaries translated from publications in more than 50 different languages from more than 180 different countries
  • Indexed with standardized CAS Lexicon terminology for enhanced retrieval and search precision
  • Enhanced with cited and citing references, legal status, and direct links to the full-text publications (where available)
  • Updated daily

CAS Reactions

The CAS reaction collection provides a current and reliable source of synthetic details sourced from journals, patents, dissertations, and seminal reference works to drive synthesis planning and process optimization.

  • Covers ~150 million reactions from 1840 to present including organometallics, total syntheses of natural products, and biotransformation reactions.
  • Enhanced with yield data, detailed reaction conditions, and experimental procedures
  • Updated daily

CAS Chemical Supplier Insights

Keep your research moving forward with CAS Chemical Supplier Insights, CAS's up-to-date resource for finding commercially available chemicals, including available quantities, prices, and supplier contact information.

  • Includes millions of unique commercially available products
  • Covers verified catalogs from hundreds of suppliers
  • Updated weekly

Chemical Regulations

Stay abreast of rapidly changing chemical regulations with CAS regulatory resources. Our collection provides the information you need to manufacture, import, export, transport, and use chemical products in key markets across the globe.

  • Covers more than ~417,000 unique chemical substances
  • Includes information from 150 regulatory inventories and lists
  • Updated weekly

CAS Markush Representations in Patents

Crucial chemistry disclosures in patents are often buried in complex CAS Markush representations that can embody hundreds of specific substances. Common search engines cannot reliably interpret this information making it difficult to achieve a comprehensive patent search, but the scientists at CAS analyze these Markush representations and make them searchable to ensure that your queries don’t miss critical documents.

  • More than 1.39 million searchable Markush representations from >570,000 patents
  • Continuous coverage since 1988, with selected coverage back to 1961
  • Updated daily


Open Access Content