CAS number

What is the CAS number and why is it key in the chemical industry?

In the chemical industry, where precision and traceability are essential, having a reliable system for identifying each substance is imperative. With thousands of compounds and elements whose names can vary depending on the language or commercial context, professionals in the sector need a universal tool that guarantees clear and unambiguous classification. To meet this need, a global standard has been established: the CAS (Chemical Abstracts Service) number, a unique identifier that allows each chemical substance to be recognised accurately and efficiently.

What does CAS stand for?

CAS stands for Chemical Abstracts Service, a division of the American Chemical Society. This service assigns each chemical substance a unique number, known as a CAS number, which acts as an unambiguous identifier at the international level.

How is a CAS number composed?

The CAS number consists of three parts separated by hyphens:

• The first digits (up to 7) identify the substance.
• The next two digits are a serial number.
• The last digit is a check digit, calculated using a specific algorithm.

CAS (Chemical Abstract Service) Number

Why is it important?

The CAS number allows you to:

• Avoid confusion between substances with similar names.
• Facilitate the search for technical, regulatory and commercial information.
• Ensure traceability in production, formulation and analysis processes.
• Comply with international regulations, such as REACH or GHS.

How is a CAS number assigned?

The assignment of a CAS number is a rigorous process that ensures the unique and accurate identification of each chemical substance. This procedure, managed by the Chemical Abstracts Service, involves four key stages:

1. Submission of information

   When a new compound is discovered, synthesised or modified, scientists submit all relevant data to CAS: chemical structure, composition, properties and other essential technical information.

2. Evaluation and verification

   A team of CAS experts analyses the information received, reviews existing scientific literature and validates that the compound meets the criteria required to be registered as a unique substance.

3. Assignment of the CAS number

   Once the information has been verified, a unique CAS number is assigned to the substance. This number becomes its permanent identifier within the CAS system.

4. Continuous updates

   As chemistry is a constantly evolving field, CAS regularly updates its database, incorporating new compounds and assigning new CAS numbers as they are discovered.

What is the CAS® Registry?

Each CAS number assigned to a chemical substance is part of the CAS® Registry, a centralised collection that is constantly updated with thousands of new entries every day. This registry is the most comprehensive and reliable database of chemical substances disclosed worldwide. Since 1957, CAS numbers have been assigned to all unique substances described in scientific literature, including compounds documented since the early 20th century.

Where is it used?

This identifier will be essential for recognising our compounds in all chemical documentation generated. Through our Chemeter software, we will be able to easily locate our substances in a continuously updated database, allowing us to correctly generate:

• Safety data sheets (SDS).
• Chemical product labels.
• Technical and regulatory documentation.