CAS Information Use Policy

Information Use Policy


CAS, a division of the American Chemical Society (ACS), is dedicated to improving people's lives through the transforming power of chemistry. This Information Use Policy (the “Policy”) aims to support scientific research performed by individuals and teams of scientists, while protecting the intellectual property rights of ACS/CAS.

The Policy applies to all Information (as defined below) unless (i) your license for CAS product(s), service(s) and/or content provide otherwise, or (ii) CAS has granted you express written permission to use Information in a manner other than as set forth below under “Authorized Use of Information”. In the event of a conflict between this Policy and the rights granted in (i) and (ii) above, then the rights granted in (i) and (ii) above shall control.

The Policy is subject to change at the discretion of CAS. Any changes made to the Policy in the future will be posted on this page and, where appropriate, notified to you by e-mail or post. Please check back frequently to see any updates or changes to the Policy.


For the purpose of this of this Policy, the terms listed below shall have the following meanings:
a. CAS RN® or CAS Registry Number®. a unique numerical identifier created and assigned to a chemical substance by CAS.
b. Database. a collection of Information structured for search and retrieval with a computer system.
c. Information. All content accessed by, or provided to, a User or Organization through a CAS product or service or provided by CAS to a User or Organization by any other means. Examples include, but are not limited to, abstracts, CAS Registry Number(s), bibliographic information, chemical reactions and structures, methods, full-text patents, substances, and reports.
d. Link. a User created fixed electronic connection to Information.
e. Molfile. a file format holding information about the atoms, bonds, connectivity and coordinates of a molecule.
f. Organization: a corporate entity, academic institution or government agency accessing and using CAS Information with the permission of CAS through a valid license or other express written grant of right by CAS.
g. Project. a research endeavor of an Organization of defined scope, staffing, and limited duration.
h. Record. A subset of Information comprised of a CAS Accession Number with any or all associated CAS Information (e.g., a CA abstract number with any or all associated Information in bibliographic Databases or a CAS RN with any or all associated Information in substance Databases.)
i. User. an individual accessing and using Information with the permission of CAS through a valid license or other express written grant of right by CAS.


A User may build a searchable Database for use by such User or a User’s Project team. Creation of centralized or networked internal and/or external Databases or Directories for any other purpose is prohibited. A Database may not be created or used with the purpose, or the effect, of avoiding subscription or other fees for accessing and using Information.

A User may download and retain no more than 5,000 Records and no more than 5,000 Molfiles at any given time. If downloaded and retained for the purpose of sharing within a Project team, the Records and Molfiles shall be deleted within 36 months of download, or, if such Records and Molfiles relate to a Project, then upon the conclusion of the Project.


Attribution. Distribution of Records or Information, whether inside or outside of an organization, to a government agency or via the Internet, in electronic or print format, shall include the following statement:
Redistributed with permission. Copyright © [Insert Year] the American Chemical Society (ACS). All rights reserved.”

Inside of User’s Organization. A User may make a de minimis amount of electronic or print copies of, and distribute to others within User’s Organization, Information and/or Records for private, internal purposes related to the Organization’s business.

Outside of User’s Organization. A User may distribute Information outside of User’s Organization in the following manners:

  • A bibliography of references, provided that the bibliography is supplemental to the main content of the User's own copyrighted or uncopyrighted work
  • A scientific publication such as a critical review, poster, presentation, research report, patent, or other communication.
  • A report to the government when the information and the reports are required by law or administrative policy.

By a Government Agency. A government agency that legally receives required Information from a User or Organization may use the Information only for the legal purpose for which it was provided. Unless expressly required by law, the government agency may not share, exchange, or redistribute the Information to another Organization, including another government agency.

Via the Internet. Except as expressly set forth in this Policy, publishing, sharing or redistributing Information via the Internet is prohibited.


Links are intended to be used only by a User or as a collaborative tool among a Project team. A User may create and distribute Links within User’s Organization for private, internal purposes related to the Organization’s business. Only Users and Organizations that hold a valid license to utilize CAS products and services may distribute, use and access Links. Links may not be aggregated or distributed for the purpose of enhancing or building a Database.


Information may not be:

Aggregated or collected:

  • Directly or indirectly, in a collection, compilation, Database, manually, via automated programing, or otherwise (e.g., a script written to extract and download Information in batches).
  • Using any script/macro to automate an otherwise manual process, including but not limited to, an attempt to download or aggregate Information utilizing an automated process.
  • For the purposes of machine learning, algorithmic development, testing or enhancing, or any other artificial intelligence purposes.


  • For commercial gain or in any other way commercially exploit the Information in conjunction with federated search tools
  • For any purpose other than as expressly set forth in this Policy, including but not limited to by assignment, sale, sublicense, loan or other means of transfer to any third party, or any commercial use, whether paid or unpaid.


For use of Information in any manner other than as expressly set forth in the Policy, please contact the CAS Customer Center.

  • Visit:
  • Email:
  • Phone: +1 (614) 447-3700 (worldwide), or (800) 753-4227 (toll-free in the North America)
  • Mail: CAS Customer Center, P.O. Box 3012, Columbus, Ohio 43210-0012, USA

Last Updated: October 2, 2020

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