Plastic waste is a huge and growing problem, and despite the best efforts of recyclers, there is some plastic waste that simply cannot be processed. Happily, the question of what to do with this stubborn waste is being addressed by a new generation of entrepreneurs.

Nzambi Matee of Kenya, founder of Nairobi-based Gjenge Makers, is one of these innovators. Using this dense plastic waste, Matee's company manufactures bricks that are actually five to seven times stronger than those made from concrete. “There is that waste they cannot process anymore....that is what we get,” Matee explains.