The CAS registry number is widely used around the world to uniquely identify chemical substances, regardless of any changes in their names, synonyms, or languages The CAS numbers of most common substances can be found in publicly available databases, but for patented or newly generated substances, their CAS numbers can only be obtained by inquiring or applying the American Chemical Abstracts Service. A mixture cannot be applied for a CAS Registry Number, but the individual components of the mixture can be applied for CAS Registry Numbers