In the complex world of chemistry, precise identification of chemical substances is paramount. Whether you are a researcher in a laboratory, a procurement manager sourcing raw materials, or a regulatory specialist, understanding and utilizing CAS Registry Numbers® (CAS RN®) is fundamental. These unique numerical identifiers are the global standard for chemical substance recognition, simplifying communication and preventing ambiguity.

What exactly is a CAS number? Developed and maintained by the Chemical Abstracts Service (CAS), a division of the American Chemical Society, a CAS number is a unique, universally recognized identifier assigned to every chemical substance described in the open scientific literature. It consists of three parts separated by hyphens: the first two segments contain up to six digits, the third segment contains a single check digit. For example, a widely used pharmaceutical intermediate might be identified by a CAS number such as 239463-85-5.

The importance of CAS numbers cannot be overstated. They provide an unambiguous way to identify substances, regardless of their common names, trade names, or systematic IUPAC names, which can often be long, complex, or vary by region. This is particularly crucial when dealing with substances that have multiple synonyms or are part of intricate synthesis pathways. For instance, when a procurement manager needs to buy a specific chemical like 5-[(2R)-2-Aminopropyl]-1-[3-(benzoyloxy)propyl]-2,3-dihydro-1H-indole-7-carbonitrile, using its CAS number (239463-85-5) ensures they are ordering the exact substance intended.

CAS numbers are essential for numerous applications: scientific literature searches, regulatory compliance (e.g., SDS sheets, REACH registration), inventory management, and, crucially, for sourcing and purchasing chemicals. When communicating with manufacturers and suppliers, providing the CAS number is the most efficient way to ensure you are getting the correct product. Many online chemical databases and supplier websites use CAS numbers as a primary search function, allowing users to quickly find product information, pricing, and availability.

For businesses looking to source chemicals from international markets, such as China, the CAS number is an indispensable tool. It bridges potential language barriers and guarantees specificity. When requesting a quote for a chemical, including its CAS number along with the desired quantity and purity specifications ensures that suppliers understand precisely what you require. Reputable manufacturers and suppliers will always provide the CAS number for their products.

In summary, the CAS Registry Number is a cornerstone of modern chemical information management. Its consistent application facilitates clear identification, seamless communication, and reliable sourcing of chemical substances, making it an essential guide for chemists, researchers, and industry professionals across the globe.