The non-hazardous secondary material (NHSM) regulations under the Resource Conservation and Recovery Act (RCRA) identify which NHSM are, or are not, solid wastes when burned in combustion units as ingredients or fuels. These regulations help combustion facilities in determining applicable emission standards for combustion units under the Clean Air Act (CAA) for the purposes of determining which Clean Air Act requirements apply:
Units that burn NHSM that are not solid waste under RCRA are subject to the section 112 CAA requirements.
Units that burn NHSM that are solid waste under RCRA are subject to the section 129 CAA requirements.
Non-hazardous secondary materials are any materials that are not the primary product of a manufacturing or commercial process, and can include post-consumer material, post-industrial material, and scrap. Many types of these materials have British Thermal Unit (BTU) or material value, and can be reclaimed or reused in industrial processes. A wide and diverse range of NHSMs exists and some percentage of the approximately 200,000 boilers or industrial furnaces use these secondary materials as substitutes for primary fuels or as ingredients.