Why Does a Soda Can Tab Stay Attached After Opening?

The tab on a modern beverage can remains attached because an earlier version created millions of small pieces of dangerous litter.

Early metal cans required a separate pointed opener. In 1959, inventor Ermal Fraze developed a convenient pull tab that allowed drinkers to tear away a scored section of the lid. The design spread rapidly, but every opened can produced a loose piece of sharp aluminum. People dropped the tabs on beaches, roads, and picnic grounds, where they could cut bare feet. Some drinkers placed the detached tab inside the can, creating a risk that it might be swallowed.

Engineers tried several alternatives, including openings that users pushed inward with a finger. These reduced litter but introduced other problems, including exposure to sharp metal around the opening.

In the 1970s, Reynolds Metals engineer Daniel Cudzik developed the stay on tab. Lifting the ring uses it as a lever. Instead of tearing away a separate piece, the tab presses a scored panel into the can while leaving both the ring and panel attached. The mechanism must be strong enough to break the seal but flexible enough to move without snapping off.

Keeping the tab attached also improves recycling because all the aluminum remains with the container. The familiar opening sound now marks the operation of a compact piece of engineering created to solve a problem that began only after cans became easier to open.