Following the commercial chemicals, chemicals produced by chemical industry can be divided essentially into three broad categories:

commodity chemicals: are chemicals produced in large quantities and in general their applications can be traced back to their chemical structure; for this reason, two commodities produced by two different suppliers but with the same chemical structure and purity are almost identical and they can be easily interchanged; they are produced by continuous plant and in general their cost is relatively low; examples of chemical commodities are ammonia and ethylene oxide;

speciality chemicals (or specialty chemicals): are constituted by a mixture of different chemical substances, that is designed and produced in order to be applied to a specific application; the formulation of specialities is the result of scientific researches carried out by the producer company, so each formulation and associated properties are unique and for this reason in the majority of the cases it is not possible to easily interchange two different specialties produced by two different suppliers; examples of applications of specialty chemicals are pharmaceuticals industry and agriculture; they are produced by batch plant and in general their cost is higher if compared with commodity chemicals;

Fine chemicals: as the commodity chemicals, they are chemical substances characterized by their chemical structure, but, on the contrary of commodity chemicals, they are produced in a small quantity; fine chemicals can be used as components in the formulation of specialty chemicals; for example active ingredients of pharmaceutical drugs are fine chemicals, but the pharmaceutical drug is a specialty chemical; examples of applications of fine chemicals are: pharmaceuticals industry, agriculture, photography chemicals and electronic chemicals; they are produced by batch plant and in general their cost is relatively high.