This blog explores the innovative research and design efforts aimed at improving urinal functionality, focusing on shape, fluid dynamics, and user engagement to reduce mess and odors in public restrooms.
Science can help solve the world’s most important problems, and what could be more important than keeping pee off your shoes? Yes, even the lowly urinal—and those who use it—can benefit from the occasional peer-reviewed study. Keeping restrooms clean and safe could all come down to the science of the shape of the thing you pee in. Let’s take a look at the science of urinals and how researchers are trying to make them better.
Surprise! Urinals are like frat houses for bacteria. Research has confirmed what many have long suspected: the spaces under and between urinals host a plethora of bacteria from a diverse range of species, including Corynebacteria, Rickettsiella, and Staphylococcus.
Even the most practiced pee-er can’t hit the bowl every time. In the United States alone, the total amount of urine overflow from the nation’s 56 million urinals is roughly 1 million liters a day. This significant volume contributes to a habitat for bacteria, leading to gross and stinky urinals.
While gross, stinky urinals may seem like an immutable fixture of human civilization, it is possible to build a better urinal. Most efforts center around a few important variables that can affect a urinal’s splash and stink potential:
The shape of the urinal bowl plays a crucial role in how effectively it can contain urine and minimize splashback. Some innovative designs have emerged to address this issue. For instance, urinal designers in Japan have incorporated cute, ladybug-shaped targets to encourage better aim. In the Netherlands, a similar design involves peeing on flies, which reportedly reduces spillage by 80%. While the exact source for this statistic is unclear, it is widely accepted that such designs help, at least to some extent.
Some urinals have taken engagement to the next level by incorporating interactive elements. For example, some designs feature a working soccer game where users aim to push a little ball into a goal with their pee stream. Others play music or even display advertisements when used, although the latter might deter some users from returning to that bathroom.
Beyond functionality, there are also artistic urinal designs that resemble various shapes, including mouths, flowers, and even religious figures. While these designs may not be scientifically tested, they contribute to a bizarre subculture of urinal art.
While many novel shapes are not scientifically designed, there is ongoing research aimed at creating better urinal shapes based on fluid dynamics. In a 2025 study, scientists compared different urinal shapes to determine which resulted in less splashback. They used a jet of dyed water from an anatomically accurate nozzle to simulate urine flow. The study found that splashback is minimized when the stream hits a rigid surface at or below an angle of 30 degrees. The winning design, named "Cornucopia," was chosen for its effectiveness, despite its vague resemblance to a Thanksgiving decoration.
In addition to shape, researchers are exploring high-tech solutions for other urinal-related issues, such as clogging and odor. A 2019 study tested a system designed to control the process of urea hydrolysis, the chemical reaction that breaks down urea into ammonia and carbon dioxide. Ammonia is known for its unpleasant smell. The system tested included pH and conductivity sensors that release acetic acid when pH reaches a certain threshold, inhibiting urea hydrolysis and thus reducing odors.
Despite all these innovations, the biggest variable in modern urinal design is one that cannot be controlled: user behavior. Ultimately, a person must care about whether their pee goes where it’s supposed to. Not everyone bothers to aim for the target, which means that even the best-designed urinal can still face challenges.
In conclusion, while the science of urinal design may seem trivial, it addresses significant public health and hygiene issues. From innovative shapes and interactive elements to high-tech solutions for odor control, researchers and designers are working hard to improve the functionality of urinals. As we continue to explore these advancements, it’s essential to remember the importance of personal responsibility in maintaining cleanliness in public restrooms. And while you’re at it, don’t forget to wash your hands!
