<P> Within the chemical industry, manufactured "chemicals" are chemical substances, which can be classified by production volume into bulk chemicals, fine chemicals and chemicals found in research only: </P> <Ul> <Li> Bulk chemicals are produced in very large quantities, usually with highly optimized continuous processes and to a relatively low price . </Li> <Li> Fine chemicals are produced at a high cost in small quantities for special low - volume applications such as biocides, pharmaceuticals and speciality chemicals for technical applications . </Li> <Li> Research chemicals are produced individually for research, such as when searching for synthetic routes or screening substances for pharmaceutical activity . In effect, their price per gram is very high, although they are not sold . </Li> </Ul> <Li> Bulk chemicals are produced in very large quantities, usually with highly optimized continuous processes and to a relatively low price . </Li> <Li> Fine chemicals are produced at a high cost in small quantities for special low - volume applications such as biocides, pharmaceuticals and speciality chemicals for technical applications . </Li>

Compounds are pure substances that by definition consist of