The site was then used by Nobel's Explosives to build a TNT / propellant factory in 1914 with Government approval. Its construction was a response to the need to drastically increase the production of shells in World War I (see Shell Crisis of 1915). The Pembrey site was one of the first purpose-built TNT manufacturing sites, in the United Kingdom, in World War I. The factory was initially owned by Nobel's Explosives, but in 1917 it was taken over by the Ministry of Munitions and it became a National Explosives Factory (NEF Pembrey).