Urea, apart from being in your pee, can also be artificially synthesised in a laboratory, and relatively cheaply at that. Most of the time it is colorless and odorless, until it is mioxed with water. Itis then that it becomes especially foul to the senses.
It can be used for a large number of uses beyond urine and cigarettes. One of the most common uses is as a fertilizer. It’s commonly used in citrus fruits to make the fruits sweeter. In fact, if you have a fruit tree in your backyard you can improve the taste of the fruit by peeing on it every day.
Urea is also used in plastics, animal feed, an explosive known as urea nitrate and an adhesive used in plywood construction. It can also be used in truck and car engines for pollution reduction from the exhaust. It’s also used for de-icing and resurfacing snowboards, and in the hair removal agent, NAIR. It is also often used as a fireproofing agent, teeth whitening, yeast, dishsoap and textile dyes.