CAS registry number

It is chemistry's de facto primary key: a numeric code unambiguously identifying a substance across languages and naming conventions. Reference infrastructure treats it accordingly - the NIST Chemistry WebBook is queryable 'by name, formula, InChI or CAS number' and tagged cas-registry and reference-database.

Portals expose it as a search field: OECD eChemPortal lists cas-number-lookup among its functions, letting users pivot from a number to hazard and regulatory records across member databases.

Identity portability is the benefit: datasets keyed to CAS numbers interoperate across hazard portals, inventories and suppliers without name-matching guesswork.

Licensing is the catch. NOAA CAMEO Chemicals states plainly that 'CAS registry numbers/synonyms/formulas' are third-party property and may not be duplicated without written permission - so bulk harvesting number-to-property mappings can infringe even where individual lookups are free. Buyers should distinguish between using CAS numbers as join keys (generally safe) and republishing annotated registries (permission-dependent), and prefer government inventory sources such as TSCA for redistributable identity tables.

1. “Test query paths. ”NIST WebBook accepts name, formula, InChI or CAS number - multiple entry points aid validation.

1. “Use portal lookups for pivoting. ”OECD eChemPortal's cas-number-lookup connects numbers to hazard data across jurisdictions.

1. “Respect property claims. ”CAMEO treats registry numbers and synonyms as third-party property requiring written permission to duplicate.

1. “Anchor to public inventories. ”TSCA-style inventories provide redistributable substance keys.

1. “Verify against datasheets. ”Hazard documentation should agree on identity before analysis proceeds.

• chemical-hazard-datasheet - hazard documents keyed by CAS identity.
• tsca-chemical-substance-inventory - the public inventory anchoring substance identity.

Sector hub: commodity-chemicals data.