CAS Frequently Asked Questions
Q. What is CAS and what do we do?
A. CAS is a division of the American Chemical Society (ACS) and is dedicated to the ACS vision of improving people's lives through the transforming power of chemistry. The CAS team of highly trained scientists identifies, aggregates, and organizes all publicly disclosed chemistry information, creating the world's most valuable collection of content that is vital to innovation worldwide. Scientific researchers, patent professionals and business leaders around the world rely on a suite of research solutions from CAS to enable discovery and fuel innovation. CAS is located in Columbus, Ohio.
Q. Who do I contact if I have a question or problem?
A. The CAS Customer Center is the central source for all inquiries. They can assist with general questions about CAS products and services, account setup and status, billing information, obtaining user documentation, and they can assist in developing search strategies when using CAS products.
Operating hours for the CAS Customer Center are 8am – 12 midnight Monday through Friday (US Eastern Time)
Q. What is a CAS Registry Number®
A. CAS Registry Numbers (often referred to as CAS RN® or CAS Numbers) are universally used to provide a unique, unmistakable identifier for chemical substances. A CAS Registry Number itself has no inherent chemical significance but provides an unambiguous way to identify a chemical substance or molecular structure when there are many possible systematic, generic, proprietary or trivial names.
CAS Registry Numbers are used in many other public and private databases as well as chemical inventory listings and, of course, are included in all CAS-produced databases.
Q. How can a publication get abstracted/indexed by CAS?
A. Our selection team of chemists determines whether a journal meets our editorial criteria for abstracting and indexing in the CAS databases. Publishers interested in having a journal covered in the CAS databases should consult the New Journal Coverage Request page for instructions, or;
Complete and submit the Journal Information Form for journals published online, or
For journals published in print, please send three different and recent issues to
Acquisitions Dept.
Q. Does CAS provide any open chemical information resources?
A. As a specialist in scientific information solutions, CAS has partnered with research organizations around the globe to tackle the evolving and complex challenge of COVID-19. The CAS COVID-19 Resources page provides access to related articles and open source data downloads.
CAS offers Common Chemistry, an open community resource for accessing chemical information. Nearly 500,000 chemical substances from CAS REGISTRY® cover areas of community interest, including common and frequently regulated chemicals, and those relevant to high school and undergraduate chemistry classes. This chemical information, curated by our expert scientists, is provided in alignment with our mission as a division of the American Chemical Society.
The CAS Source Index (CASSISM) Search Tool is another free online resource intended to support researchers and librarians who need accurate bibliographic information. Use this free tool to quickly identify or confirm journal titles and abbreviations for publications indexed by CAS since 1907, including serial and non-serial scientific and technical publications. Locate the bibliographic details you need quickly and easily. Search by Title, Abbreviation, CODEN, ISBN, or ISSN.
The Pistoia Alliance Chemical Safety Library (CSL) is a new open-access platform that streamlines access to hazardous reaction information crowd-sourced from academic, industry and government institutions around the world. Developed and hosted by CAS, visitors can search for hazardous reaction information and contribute new information.
Q. Where is CAS located, and do you have directions for visitors?
A. CAS is located at:
See this map and directions for visitors.