CAS Number - TX
From imde.io
CAS Number (Chemical Abstracts Service Number)
The CAS Number (Chemical Abstracts Service Registry Number) is a unique numerical identifier assigned to chemical substances globally, managed by the American Chemical Society (ACS).
- Format: Three-part structure XXXXXX-XX-X (e.g., 7440-02-0 for nickel).
- Purpose: Used worldwide as a chemical registry identifier in research, industry, and regulatory databases.
- Scope: More extensive than EC numbers, covering all chemical compounds, including commercial formulations, polymers, and biochemical compounds.
- Managed by: CAS Division of the American Chemical Society (ACS).
- Example: Nickel (Ni) → CAS Number: 7440-02-0.
Relationship Between EC Number and CAS Number
- Many substances have both an EC Number and a CAS Number.
- EC Numbers are used exclusively within the EU regulatory framework (e.g., REACH, ECHA databases).
- CAS Numbers are used globally, including in the EU, the U.S., and other regulatory databases.
- A one-to-one relationship is not guaranteed:
- Some substances may have an EC Number but no CAS Number (e.g., naturally occurring minerals or regulatory groupings).
- Some CAS Numbers do not have an EC Number, especially for complex mixtures or proprietary substances.
- Both numbers are often cross-referenced in regulatory databases (e.g., ECHA’s REACH database, ChemSpider, PubChem).
