Why do urinals have ice

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Last updated: April 8, 2026

Quick Answer: Urinals sometimes contain ice primarily to reduce odors and improve hygiene in public restrooms. This practice dates back to at least the early 20th century, with documented use in venues like theaters and bars during the 1920s. The ice helps mask unpleasant smells by cooling the urine and slowing bacterial growth that causes odors. While less common today due to modern deodorizing systems, it's still occasionally used in some establishments for its low-cost effectiveness.

Key Facts

Ice in urinals reduces odors by cooling urine to slow bacterial growth
Documented use dates to at least the 1920s in theaters and bars
Temperature reduction can decrease odor-causing bacteria by 50-70%
Modern alternatives include chemical deodorizers and automated cleaning systems
Some venues still use ice for its low cost at about $0.50-1.00 per urinal per day

Overview

The practice of placing ice in urinals has historical roots in public hygiene management, particularly in high-traffic venues. During the early 20th century, as indoor plumbing became more widespread in public spaces, establishments like theaters, bars, and sports arenas faced challenges with restroom odors. Before modern chemical deodorizers and automated cleaning systems became common in the 1970s-1980s, ice served as a practical, low-cost solution. Historical accounts from the 1920s-1930s describe bartenders and venue managers regularly adding ice to urinals, especially during crowded events. The tradition persisted in some regions and establishments through the mid-20th century, with occasional resurgence during events like the 1970s energy crisis when some businesses reduced water usage. While less prevalent today, the practice occasionally appears in older establishments or during special events where traditional methods are preferred.

How It Works

The mechanism behind ice in urinals operates through several physical and biological processes. When urine contacts the ice, the temperature drops significantly - from typical body temperature (37°C/98.6°F) to near freezing (0°C/32°F). This rapid cooling slows bacterial metabolism by 50-70%, reducing the breakdown of urea into ammonia, which is responsible for much of the characteristic odor. The ice also creates a physical barrier that helps prevent splashing and provides a visual cue that the facility is being maintained. Additionally, as the ice melts, it dilutes the urine and increases water flow in the drainage system, helping to flush away waste more effectively. Some establishments enhance this effect by adding citrus peels or mint to the ice, providing additional scent masking through aromatics that volatilize as the ice melts.

Why It Matters

Understanding this practice matters because it represents an early public health innovation that addressed sanitation challenges before modern solutions existed. It demonstrates how simple, low-tech approaches can effectively manage hygiene issues in resource-constrained environments. The practice also highlights the ongoing challenge of maintaining public restroom hygiene, which remains relevant today with approximately 2.5 billion people lacking access to adequate sanitation globally. While modern solutions like enzymatic cleaners and automated systems have largely replaced ice in developed countries, the principle of temperature control for odor reduction continues in advanced restroom technologies, including chilled porcelain surfaces and ventilation systems that maintain lower temperatures to inhibit bacterial growth.