6.12.2023

CAS Number

The CAS Number (CAS = Chemical Abstract Service) is used for identification of chemical substances. It is composed of numbers and dashes, and is structured as follows:

  1. Sequence of digits with up to 7 digits
  2. Dash
  3. Sequence of exactly 2 digits
  4. Dash
  5. Check digit
Examples:
  • 67-64-1 Acetone
  • 7440-17-7 Rubidium
  • 7647-01-0 Hydrochloric acid