Carbon and stainless steel IBCs are the only intermediate bulk containers that are approved per NFPA 30 Section 9.4.1 (1) and UL 142 for the long-term storage of flammable and combustible materials. Metal alloy IBCs are engineered to be compatible with dense, heavy-weighted, corrosive, acidic, caustic, inert, and reactive materials as well as food grade, consumable goods.