You’re probably familiar with the cliché “everything but the squeal” to refer to the efficient, waste-not-want-not form of meat processing. But you may not know that the ancient Romans were also economical about their use of waste products—specifically, their own waste. Human urine and feces were used in daily life in at least six different (and sometimes dubious) ways. 

1. WHITENING TEETH

When left out too long, urine decomposes into ammonia, which is a great cleaning product that takes out stains easily. Roman authors like Catullus attest to people using both human and animal urine as a mouth rinse that helped whiten their teeth.

2. GROWING JUICY FRUIT

Urine also contains nitrogen and phosphorous, which are both useful for growing plants. The Roman author Columella wrote that old human urine was particularly useful for growing pomegranates, making them juicier and tastier.

3. MAKING THEIR TOGAS BRIGHT AND COLORFUL

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The ammonia in urine was also used to clean togas in a place called a fullery. The first stage of cleaning involved men jumping up and down on the togas in large vats with urine inside, like living washing machine agitators, while the second stage often included dirt or ash. Both helped dissolve grease that accumulated on the togas and made them bright again.

4. CURING DISEASED ANIMALS

From the Roman author Columella again come some suggestions for using human urine, this time for veterinary purposes: Sheep with bile issues were given human urine to drink, while those with lung issues were given urine through the nose. Sick bees could also be given human urine, and bird flu was cured by putting tepid urine on their beaks.

5. TANNING

The Romans frequently employed urine, dog feces, and sometimes human feces in tanning—no, not for sunning themselves outside, but for making leather. A good long soak in urine would help remove hair from the pelt, and then feces were ground into it, sometimes for hours at a time. The enzymes made by the bacteria in the feces softened the hide, making it more supple.

6.  FERTILIZING FIELDS 

Also known as “night soil,” fertilizer made from human feces can help plants grow—but it can also help spread disease. The Romans did use human feces and urine in their gardens, as the organic portion of the poo and the nitrates, phosphorous, and potassium of the urine nourished plants. There seems to have been a healthy trade in feces in Roman times, as the stercorarii—"poop collectors"—were documented to have collected and sold it. 

Although human waste was used in a wide variety of ways in ancient Rome, it’s not clear exactly how it was gathered. Latrines—both public and private—were undoubtedly useful for amassing a combination of urine and feces, but would not have worked for tanners, who needed unadulterated urine. It is clear that the collection of waste wasn’t free. The emperor Vespasian levied a tax on urine around 70 CE. Reportedly, when his son Titus expressed disgust at the tax, Vespasian retorted, "pecunia non olet"—"money doesn’t stink." His tax was so famous that his name is still used today as a general term for public urinals (vespasiennes in French and vespasiani in Italian). 

So the next time you think to appreciate modern bathroom hygiene, be sure to give thanks to the minor Roman deity Cloacina.  Because if you anger this goddess of the sewer system, she is sure to send you running for a plumber.