CAS Number Guide

How to Search Chemicals by CAS Number

Published 2025-01-22

Exact-match CAS searching, synonym searching and molecular formula searching explained.

Searching by CAS Number should always be an exact match against a normalised value: strip whitespace, keep the hyphens and validate the check digit. When the CAS Number is unknown, a chemical name or synonym search is the next step, followed by molecular formula searching for structural exploration. A good chemical database indexes all three so a single search box can serve every workflow.

Related Compounds

C9H8O4
AspirinActive Pharmaceutical Ingredients
CAS 50-78-2C9H8O4MW 180.16
View Details
C8H10N4O2
CaffeineHeterocyclic Compounds
CAS 58-08-2C8H10N4O2MW 194.19
View Details

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