increase the sensitivity of the explosive that is approximately the same size as a hull one type of hull that has a plurality of micro voids and is capable of acting as an inert bulking agent to reduce the density of the explosive composition is a rice hull the micro void characteristic of rice hulls is discussed in chapter 19 of rice chemistry and technology written by bienvenido o juliano which is incorporated herein by reference rice hulls also have a waxy coating that complements the water resistant characteristic of the heavy anfo however any other type of hull that exhibits micro voids and is capable of acting as an inert bulking agent is also feasible the ranges of the raw materials for an explosive composition comprised of heavy anfo and a plant derived inert bulking and sensitizing additive is set forth in table i the combination of calcium nitrate and sodium nitrate has a maximum of 20 relative to final blend of heavy anfo and the hulls it should be noted that the composition set forth in table ii assumes that an emulsion explosive is being utilized that comprises at least calcium nitrate and sodium nitrate as previously noted emulsion explosives with other compositions are feasible the ranges of the raw materials for an embodiment of an explosive composition comprised of heavy anfo and a plant derived inert bulking and sensitizing additive that has characteristics that approach those of anfo are set forth in table ii the combination of calcium nitrate and sodium nitrate has a maximum of 12 relative to.