Yes, but I’d say they help more than they solve. A charcoal filter—usually activated carbon—can trap some of the odor-causing molecules that come off food scraps, pet waste, and general rubbish. In a busy urban trash can, that can make the area around the bin smell a little less sharp, especially when the lid is closed and the filter is still fresh.
But here’s the catch: trash cans are rarely airtight. People open them all day, bags leak, liquid collects at the bottom, and the filter only treats the air that actually passes through it. If the filter is damp, clogged with dust, or simply old, it stops doing much. A small filter also can’t handle a huge volume of smelly waste on a hot day.
So do they really reduce odors? In my experience, they can reduce the worst of the smell for a while, but they’re not a magic fix. They work best as one part of a broader approach: a well-fitted lid, regular emptying, washing the bin itself, separating food waste where possible, and replacing the filter on a realistic schedule. If a city just installs charcoal-filter bins and forgets about maintenance, the odor problem will come right back.
The honest answer is that charcoal filters are useful, but they’re a support tool, not a cure. They can take the edge off urban bin smells, but the real difference comes from good bin design and consistent cleaning.