Every time you touch a brass doorknob, something invisible begins to happen. Unlike most surfaces, brass doesn't simply collect microbes. Thanks to the copper it contains, it actively works against many of them.

Brass is an alloy made primarily of copper and zinc. When bacteria, viruses, and fungi land on its surface, the copper begins disrupting them in several ways at once. It damages their outer membranes, interferes with essential proteins, and breaks apart their genetic material. Many microbes that can survive for days on stainless steel become inactive much more quickly on brass and other copper alloys.

This isn't just an interesting quirk of chemistry. Scientists have spent decades studying copper's antimicrobial properties, and some hospitals have installed copper alloy fixtures on high-touch surfaces such as bed rails, tray tables, IV poles, and door hardware to help reduce microbial contamination between routine cleanings.

Brass doesn't make a surface sterile, and it doesn't replace regular cleaning. Dust, grease, and other debris can reduce its effectiveness. But unlike stainless steel, brass has an inherent antimicrobial property that keeps working in the background, quietly reducing many of the microbes that land on it.

Long before scientists understood microbes, people were already reaching for one of the few metals that could quietly fight them.