The world is full of icons that warn us to be afraid — to stay away from this or not do that. And many of these are easy to understand because they represent something recognizable, like a fire, or a person slipping on a wet floor. But some concepts are hard to communicate visually, especially in a way that will work for generations to come.  99% Invisible teamed up with Vox to bring you this video about the challenges designers face in developing warning symbols that last.

Why Danger Symbols Can’t Last Forever

Check out all of Vox’s videos. They’re top drawer.