An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Final Rule: Reconsideration and Final Amendments for Non-Hazardous Secondary Materials that are Solid Waste

On this page:

Rule Summary

These non-hazardous secondary materials (NHSM) revisions were finalized within a joint rulemaking under the Clean Air Act for commercial and industrial solid waste incinerators (CISWI). Refer to Section III - "NHSM Final Revisions" for the NHSM revisions in the rulemaking package. The targeted changes to the NHSM regulations are listed at the end of the document under "Part 241 - Solid Wastes Used As Fuels or Ingredients in Combustion Units." The NHSM part of the preamble begins on page 9135 of the Federal Register notice for the consolidated rulemaking.

This rule amends title 40 of the Code of Federal Regulations (CFR) part 241, which was originally codified by the 2011 NHSM rule. EPA re-examined that March 2011 NHSM rule and has finalized amendments and clarifications on certain issues where the Agency received new information, as well as specific targeted revisions that are appropriate to allow implementation of the rule as the Agency originally intended.

These amendments clarify and provide direction to facilities applying the legitimacy criteria, and emphasize the flexibilities embodied in the rule. The final revisions also list several NHSMs as categorical non-wastes when used as a fuel, and provides a process for the regulated community to request an EPA rulemaking that would identify additional materials as categorical non-waste fuels. Please see the fact sheet and the federal register notice for additional information.

Top of Page

Rule History

On March 21, 2011, EPA promulgated the base NHSM regulations titled "Identification of Non-Hazardous Secondary Materials that are Solid Waste" (often referred to as the "NHSM Final Rule"). The NHSM final rule provides the standards and procedures for identifying whether NHSMs are solid waste under the Resource Conservation and Recovery Act (RCRA) when used as fuels or ingredients in combustion units.

  • Combustion units that burn non-hazardous secondary materials that are not solid waste under RCRA are subject to the section 112 Clean Air Act requirements for commercial, industrial or institutional boilers or cement kilns.
  • Combustion units that burn non-hazardous secondary materials that are solid waste under RCRA are subject to the section 129 CAA requirements for solid waste incinerators.

Following promulgation of the NHSM final rule, the regulated community expressed concerns regarding the regulatory criteria for a NHSM to be considered a legitimate, non-waste fuel and how to demonstrate compliance with those criteria. The Agency re-examined the NHSM final rule and published targeted revisions on February 7, 2013. The revisions,among other things, added categorical non-waste determinations and provided a process to add additional NHSMs to the list.

Top of Page

Additional Resources

Information developed for the February 7, 2013 Final Rule:

Information developed for the proposed revisions to the Final Rule (Commercial and Industrial Solid Waste Incineration):

Top of Page