Defining Substances and Ingredients - Identifiers

Substance Identifier Code Systems in Current Use

  1. CAS (Chemical Abstracts Service)
    • 100,000,000+ 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
  2. EC/EINECS (European Inventory of Existing Commercial Chemical Substances)
    • 100,000+ records covering European commercial chemicals
    • sequential with check digit
    • free to use
  3. RxCUI (RxNorm Concept Unique Identifer)
    • 12,000+ records covering substances in medicinal products
    • sequential without check digit
    • free to use
    • no code request service
    • codes created without definitions
  4. SNOMED CT Substance Concept
    • 25,000+ 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
  5. UNII (Unique Ingredient Identfier)
    • 75,000 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
CAS Registry Substance Record for (-)-Atropine



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