Rice husk ash (RHA), a byproduct of rice milling, is being used in India to create a more eco-friendly concrete recipe. "Being locally available, renewable and non-toxic, RHA contributes to the concept of green concrete," said Sixtus Paulson, a civil engineer at Travancore Titanium Products. The use of RHA has been found to create a stronger, more durable and workable concrete block while reducing the amount of cement required in the mix, making the product less expensive and greener.