Urea

Urea is an organic compound. It was first found in urine in 1773 by the French chemist Jean Rouelle. It is also called Carbamide, and its chemical names are Carbonyl Diamide (used in inorganic chemistry) and Diaminomethanal (used in organic chemistry).
In humans, it is a normal component of blood and many body tissues. It is produced in the liver, where ammonia, a very toxic substance, is changed into urea, which has a very low toxicity, so low in fact, that it is many times less toxic than table salt. Most of the urea produced in this way is not needed by the body, and is removed from the blood in the kidneys and taken out of the body in urine.