Urea waste product formed in the mammalian liver when nitrogen compounds are broken down. It is excreted in urine. When purified it is a white, crystalline solid. Urea is transported in the blood to the kidneys where it is filtered out; its concentration in urine is about 60 to 70 times as great as in blood. In industry it is used to make urea formaldehyde plastics, pharmaceuticals and fertilisers. In 1773 it was noted that urea gives off ammonia when heated. This knowledge provided a clue to its structure. Later, in 1828 the artificial formation of urea from ammonia and cyanic acid was discovered. Urea became the world's leading N-fertiliser in the mid-1970s.

Urea fertiliser is used in Bangladesh as a major nitrogen (N) source for rice cultivation. Of the total nutrients used in the country, nitrogen alone constitutes about 80 percent. About 9,42,771 tons of nutrient N alone were used in 1995-1996, out of total 11,79,3910 tons of nitrogen, phosphorus (P), potassium (K), sulphur (S), and zinc (Zn) nutrients

With substantial natural gas reserves, Bangladesh is well placed to convert this resource to fertiliser for agricultural development. Six urea fertiliser factories sponsored by BCIC are currently operating. They are NGFF, Fenchuganj; UFFL, Ghorashal; ZFCL, Ashuganj; Palash, Ghorashal; CUFL, Chittagong and Sarishabari (Jamuna), Jamalpur. These factories produced about 1.6 million tons of urea in 1996-1997, which provided about 75% of the total consumption. The Jamuna Fertiliser Factory produces good quality pea-sized granular urea, which is most suitable for rice cultivation. Another private sector fertiliser factory named kafco situated on the left bank of the karnafuli river near Patenga in Chittagong is now also operating. [Md Akhter Hossain Khan]