The urea serves an important role in the metabolism of compounds containing nitrogen by animals, and are the main nitrogen-containing substances in the urine of mammals. It is colorless, odorless solid, very soluble in water, and is practically non-toxic (LD50 is 15 g/kg for rats). Dissolved in water, this is not an acid or base. The body uses it in many processes, particularly the excretion of nitrogen. Widely used in urea fertilizer as a source of nitrogen and mer