Beneath the succession of brown rusty rooftops in Kibera slums, home to hundreds of thousands of Nairobi city residents, women voices pierce the air. From a distance, one can hear occasional laughter, snatches of conversation, labored breathing, and hasty movements of people at work. A closer look reveals a group of about six women. Some are bending while others are down on their knees, with all hands rigorously making dough out of some black solid mass. “This is a mixture of charcoal dust, soil and water. We want to bind it and make charcoal briquettes,” says Felistas Asiko, a mother of four, who like the others surrounding her, earns a living from selling the fuel.