an explosive composition is provided that is comprised of a heavy anfo and grain hulls . in one embodiment , the grain hulls are comprised of rice hulls . the grain hulls serve both as an inert bulking additive that reduces the density of the composition and as a sensitizer that reduces the energy needed to reliably detonate the composition . also provided is a method for manufacturing an explosive composition comprised of heavy anfo and grain hulls , such as rice hulls . additionally , a method of using an explosive comprised of anfo and grain hulls in a mining operation is disclosed .