Human urine has been used to create environmentally friendly bricks by university students in South Africa. They combined urine with sand and bacteria in a process that allows the bricks to solidify at room temperature. The bio-bricks are created through a natural process called microbial carbonate precipitation. It’s not unlike the way seashells are formed, said Lambert’s supervisor Dr Dyllon Randall, a senior lecturer in water quality engineering. The development is also good news for the environment and global warming as bio-bricks are made in moulds at room temperature. Regular bricks are kiln-fired at temperatures around 1 400°C and produce vast quantities of carbon dioxide.