What is a CAS Number? What is its Format?
The CAS Registry is a substance collection containing information on many chemicals. Furthermore, it is updated daily and is relied upon by many experts like scientists, manufacturers, and regulators. Also, the registry links to all relevant publications, chemical suppliers, formulations, reactions, and data on the molecules of interest.
Additionally, compounds in this registry are classified using a CAS Registry Number (CAS RN), or simply called CAS number. It has the following characteristics:
- A distinctive numerical identifier for each chemical substance
- It has no chemical significance.
- It contains up to 10 digits separated into three parts by two hyphens:
- The first part of the CAS Number contains two to seven digits.
- The second part of the CAS RN contains two integers.
- The third part of the number holds a single check digit (to verify the validity of a CAS number).