CASregistry

CASregistry refers to the CAS Registry, a comprehensive, curated database of chemical substances maintained by the American Chemical Society’s Chemical Abstracts Service (CAS). Each registered substance is assigned a unique numeric identifier called a CAS Registry Number (CAS RN), used to unambiguously identify chemicals across scientific literature, patents, and regulatory documents.

The registry covers a broad range of chemical substances, including small molecules, polymers, alloys, minerals, isotopically labeled substances, and various reaction products. For each substance, the entry typically includes a preferred name, a set of synonyms, the CAS RN, molecular formula, molecular weight, and available structural representations. Entries may also link to bibliographic and source information from literature and patent records. In many cases, data such as alternative identifiers and cross-references to related records (including representations like SMILES or InChI) are provided.

Data in the CAS Registry are curated and updated by CAS staff and contributing publishers, with ongoing efforts to expand coverage and improve accuracy. The registry is designed to support consistent indexing and discovery, serving as a common reference point for researchers, industry, and regulators.

Access to the CAS Registry is typically provided through licensed products and services, most notably SciFinder and STN. These platforms offer search, retrieval, and integration capabilities built around CAS Registry Numbers. Because the resource is proprietary, public access to full substance data is limited, and institutions commonly rely on licensed access through libraries or corporate subscriptions.

Overall, CASregistry plays a central role in standardizing chemical identification and enabling reliable data integration across diverse sources and applications.