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CAS Registry Numbers on STN: Preface.


This booklet is designed for a person who wants to find or verify the Chemical Abstracts Service® Registry Number for a chemical substance. It is a brief introduction to online searching of the REGISTRY File on STN International®, the scientific and technical information network, for this specific need.

You do not need searching experience or a chemistry background to use this booklet. You will learn how to access STN International, search the REGISTRY File, and gain some basic online searching skills.

Online searching of the REGISTRY File is sometimes easy and straightforward. Yet it can be complicated even for a trained search specialist with a chemistry background. This booklet is a starting point. It will help you learn how to find some answers to your requests for CAS Registry Numbers®.

It is important that you verify whether or not a retrieved answer is correct. We will give you some tips on how to do this. Sources for help will also be given.

After studying this booklet, you will be able to conduct these simple searches:

  1. You have a chemical substance name and need to find its CAS Registry Number
  2. You have a number and need to verify if it is the correct CAS Registry Number for your substance or want to get its associated substance information.
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