Defining Substances and Ingredients - Identifiers
Substance Identifier Code Systems in Current Use
- CAS (Chemical Abstracts Service)
- 250,000,000+ records covering all published chemical literature (15,000 new records each day)
- sequential with check digit
- copyrighted
- new codes available for fee
- codes created based on registrar and user needs
- EC/EINECS (European Inventory of Existing Commercial Chemical Substances)
- 110,000+ records covering European commercial chemicals
- sequential with check digit
- free to use
- RxCUI (RxNorm Concept Unique Identifer)
- 15,000+ records covering substances in medicinal products
- sequential without check digit
- free to use
- no code request service
- codes created without definitions
- SNOMED CT Substance Concept
- 30,000+ records covering substances in medicinal products
- sequential without check digit
- countries pay fee for use
- new codes available free
- codes created without definitions or data model
- UNII (Unique Ingredient Identfier)
- 130,000+ public records covering substances in regulated products (1,000 new records each month)
- nonsequential constant length alphanumeric with check character
- free to use
- new codes available free by REQUEST
- codes created based on registrar and user needs
- rich data mapped to numerous other datasets and identifiers (highly interoperable)
- codes created based on a standized data model (ISO 11238)
CAS Registry Substance Record for (-)-Atropine