The Chemical Abstracts Service Chemical Registry System. VIII. Manual Registration

The Chemical Abstracts Service (CAS) Chemical Registry System is a computer-based system that uniquely identifies chemical substances on the basis of structure and composition. For the small number of substances for which there is little or no structural description, special procedures have been developed. Analogous procedures are also necessary to process those substances that have completely described structural characteristics, but which lie beyond the bounds of the system. Examples of such substances are polypeptides, enzymes, “Colour Index” names where the dye structure has not been revealed, alloys, etc. The manual identification process and the combination of manual and machine processing necessary to record these substances in the CAS Chemical Registry System are described. Registration of compounds in the UVCB section of the TSCA Inventory is also discussed.