Romans Used Urine for Laundry

In ancient Rome, the task of keeping garments clean fell to specialized laundries known as fullonicae, where workers, called fullers, employed an unconventional yet highly effective cleaning agent: stale urine. Far from being merely a waste product, urine was a valuable commodity, essential for maintaining the cleanliness and appearance of Roman textiles. These communal laundries were a common sight in Roman cities, reflecting the societal need for clean clothing and the resourcefulness of the era.

The efficacy of urine as a cleaning agent stems from its chemical composition. When urine is left to stand, the urea within it decomposes, producing ammonia. This ammonia is a powerful alkaline substance that acts as a natural detergent, capable of dissolving stubborn grime, grease, and dirt from fabrics. For wool, in particular, the ammonia was crucial for the process of fulling, which involved cleaning and thickening the fabric by breaking down natural oils (lanolin) and causing the fibers to felt together, making the material denser and more durable.

Fullers would collect urine from public urinals and large jars placed strategically on streets. Once collected, the urine would be stored in vats to allow the ammonia to develop. Clothes were then soaked in this solution, and fullers or their slaves would physically tread on the fabric in large tubs, agitating it much like a modern washing machine to work out the impurities. The importance of urine was so significant that Emperor Vespasian even imposed a tax on its collection and distribution, leading to the famous Latin phrase "pecunia non olet," or "money doesn't stink," supposedly uttered in response to his son's concerns about the revenue source.