Plastic waste presents a number of environmental problems. Although only a small fraction of it enters rivers, lakes, and oceans, it can be transformed there into micro- and nanoplastics that are harmful to aquatic organisms. When plastic waste is buried in landfills or incinerated, it generates heat and carbon dioxide. However, plastic waste also offers great opportunities if its economic value can be increased substantially through upcycling processes that convert it into more valuable chemical products. On page 437,Vol. 370, Issue 6515, of Science journal, Zhang et al. report on an upcycling process that converts polyethylene (often used for packaging and grocery bags) into long-chain alkylaromatics that can be sulfonated to make biodegradable surfactants. This process operates at a moderate reaction temperature, does not need any solvent or added hydrogen, and produces only a small amount of light-gas by-products such as methane.