ELI5: How do activated charcoal filters remove odors?

Activated charcoal filters remove bad smells by trapping stinky odor particles on their surface like sticky flypaper traps flies.

Think of normal charcoal, like the black lumps you use for a backyard barbecue. Activated charcoal is special because it has been superheated with steam or air, which blasts millions of tiny, invisible tunnels, nooks, and crannies into it. It ends up looking like a microscopic sponge full of millions of hidden caves. Because of all these tiny caves, just a single teaspoon of this charcoal has more surface area than an entire football field!

Here is how it works to clean the air in everyday life:

• The smells float around: When you fry fish, burn toast, or leave dirty socks in a room, tiny invisible odor particles float through the air.
• The air meets the charcoal: A fan—like the one in an air purifier, the hood over your stove, or even the inside of your refrigerator deodorizer—pulls that smelly air toward the charcoal filter.
• The trapping happens: As the stinky particles pass through the filter, they crash into the millions of tiny caves in the charcoal. The charcoal uses a natural invisible pulling force called adsorption to grab onto these smell particles.
• The smells get stuck: Instead of soaking up the smells like water in a sponge (which is absorption), the charcoal sticks the odors firmly to its surfaces (which is adsorption).
• Fresh air leaves: Since the smelly bits are stuck inside the charcoal caves, only clean, fresh air passes out the other side.