Websites using cas registry numbers as a keyword

Pharma info source provides information on chemical suppliers, cas suppliers, cas numbers, CAS Suppliers List, cas supplier database, surplus materials and pharma services

Chem Sources - Chemical information database used by researchers & industrialists to find worldwide producers of laboratory & commercial chemicals for sale. Free searches.

KemicalHub facilitate buy/sell of chemicals, get latest requirements from chemical exporters/importers, find cas numbers, laboratory, chemical companies

chemBlink provides a free database of chemicals from around the World, searchable for product identifications, CAS numbers, molecular formulas and structures, chemical and physical properties, safety data, suppliers and their web addresses.

STN International is the online scientific and technical information service dedicated to meeting the information needs of scientists, engineers, and information professionals throughout the world. STN provides a complete collection of in-depth databases in science and technology to give you quick, direct links to the literature, patents, and chemical catalogs. STN on the Web combines the STN command functionality with web browser technology. The complete set of STN commands, as well as graphic chemical structure searching is available. Also available are browser features such as hyperlinks, images integrated in text, and context-sensitive help. STN on the Web also offers seamless access to electronic and paper full-text resources, as well as the wealth of STN's user documentation just a click away.