The scale of chemical manufacturing tends to be organized from largest in volume (petrochemicals and commodity chemicals), to specialty chemicals, and the smallest, fine chemicals.
The petrochemical and commodity chemical manufacturing units are on the whole single product continuous processing plants. Not all petrochemical or commodity chemical materials are made in one single location, but groups of related materials often are to induce industrial symbiosis as well as material, energy and utility efficiency and other economies of scale.
Those chemicals made on the largest of scales are made in a few manufacturing locations around the world, for example in Texas and Louisiana along the Gulf Coast of the United States, on Teesside in the Northeast of England in the United Kingdom, and in Rotterdam in the Netherlands. The large scale manufacturing locations often have clusters of manufacturing units that share utilities and large scale infrastructure such as power stations, port facilities, road and rail terminals. To demonstrate the clustering and integration mentioned above, some 50% of the United Kingdom's petrochemical and commodity chemicals are produced by the Northeast of England Process Industry Cluster on Teesside.
Specialty chemical and fine chemical manufacturing are mostly made in discrete batch processes. These manufacturers are often found in similar locations but in many cases they are to be found in multi sector business parks.