Cigarette butts are one of the most common kinds of litter, found everywhere from land to waterways. The tobacco and paper in them will break down, so those can be composted. But the filters contain a plastic, and that can take years to decompose. Yet if the butts are carefully processed, the cellulose acetate can be used to make things such as park benches and pallets. Recycling companies like TerraCycle are also refining their processing methods to create higher-end plastic products.