[Attalus]

It is waste, but not infected waste like feces. The kidneys main role is not to excrete waste but to maintain the body's electrolyte and acid-bace balance, so the content of urine is mainly water, sodium, potassium, chloride, and bicarbonate;carbon dioxide, depending on what it's acidity is. There are also nitrates and bilirubin degenerative products, from protein breakdown and hemoglobin metabolism which give it the distinctive smell and odor, and various other substances, depending on the individual's health status, such as glucose, but the healthy individual's urine is quite sterile.