Facility Regulatory Tour
Quick Reference
Hazardous Waste Identification Flowchart

Step 1
# 1 - Is Your Material a Solid Waste?
The first step is to determine if the material in question is classified as a solid waste. If the material is NOT a solid waste, it cannot be a hazardous waste. For the purposes of the Resource Conservation and Recovery Act (RCRA), the definition of solid waste is not limited to wastes that are physically solid. Many solid wastes are liquid, semi-solid, or contained gaseous material.

  • A material is considered a solid waste if it is discarded by being:
    • Abandoned. A material is abandoned if it is disposed of, burned, incinerated, or sham recycled.
    • Inherently waste-like. These are materials which pose such a threat to human health and the environment that they are always considered solid wastes; these materials are considered to be inherently waste-like. (e.g., dioxin wastes).
    • A discarded military munition. Military munitions are all ammunition products and components produced for or used by the U.S. Department of Defense (DOD) or U.S. Armed Services for national defense and security.
    • Recycled in certain ways. A material is recycled if it is used or reused (e.g., as an ingredient in a process), reclaimed, or used in certain ways (used in or on the land in a manner constituting disposal, burned for energy recovery, or accumulated speculatively). Specific exclusions to the definition of solid waste are listed in the Code of Federal Regulations (CFR) at 40 CFR section 261.4(a). Many of these exclusion are related to recycling.

  • If the material in question meets any of the provisions above, you may have a solid waste. If you answered NO to all of the above provisions, you do not have a solid waste.
Do you have a solid waste?

YES - click here to go to Step #2 below.
NO - the material does not qualify as a solid waste, and therefore cannot be regulated under RCRA Subtitle C.

Step 2
# 2 - Is Your Solid Waste Excluded from Hazardous Waste Regulations?
After you have determined that you have a solid waste on hand, the next step is to determine if that solid waste is excluded from RCRA regulation.

  • EPA grants specific exclusions from some hazardous waste regulations if certain conditions are met. Some materials are excluded from the definition of solid waste, while some solid wastes are excluded from the definition of hazardous waste. Knowing these exclusions can be helpful in waste management programs.

  • Some materials that are excluded from the definition of solid waste (and therefore are NOT hazardous) include, but are not limited to: (see 40 CFR 261.4(a) for a complete list)
    • Domestic sewage and mixtures of domestic sewage
    • Industrial wastewater discharges that are point source discharges
    • Radioactive waste
    • Excluded scrap metal
    • Irrigation return flow
    • In situ mining waste
    • Spent sulfuric acid
    • Spent wood preservatives
    • Hazardous secondary materials from the petroleum refining industry
    • Shredded circuit boards
    • Used cathode ray tubes
    • Solvent-contaminated wipes that are sent for cleaning and reuse are not solid wastes from the point of generation
    • Hazardous secondary material generated and legitimately reclaimed within the United States or its territories and under the control of the generator.
    • Hazardous secondary material that is generated and then transferred to a verified reclamation facility for the purpose of reclamation is not a solid waste.
    • Hazardous secondary material that is generated and then transferred to another person for the purpose of remanufacturing is not a solid waste.

    These wastes are not hazardous waste because they are excluded from the legal definition of "solid waste."

  • Some materials that are excluded from the definition of solid waste (and therefore are NOT hazardous) include, but are not limited to: (see 40 CFR 261.4(b) for a complete list)
    • Household hazardous waste (pesticides, cleaners)
    • Agricultural wastes
    • Fossil fuel combustion wastes
    • Cement kiln dust (unless the facility burns hazardous waste as fuel)
    • Arsenically treated wood
    • Petroleum-contaminated media and debris from USTs
    • Used oil filters
    • Spent chlorofluorocarbon refrigerants

    These solid wastes are excluded from the definition of hazardous waste by EPA.

  • In addition, EPA has issued separate regulations for the storage, disposal, or treatment of a number of waste streams which might be considered hazardous waste, but for which there are extenuating issues. These include the following and are not regulated as RCRA hazardous waste: The list above is NOT comprehensive. If your waste is not on the list above, it may still be excluded from RCRA regulation. See 40 CFR 261.4 for a complete list of those wastes exempt from hazardous waste regulation. Furthermore, if your waste IS listed above, that does not mean you are automatically exempt. Each exemption above is conditional and facility managers should review applicable sections of 40 CFR 261 and contact their State's hazardous waste program for clarification on exemptions.

Is the solid waste excluded from hazardous waste regulation?

YES - the waste is exempt (not regulated) under RCRA Subtitle C.
NO - click here to go to Step #3 below.

Step 3
#3 - Is Your Solid Waste a Listed Waste?
Once you have determined that your solid waste is not excluded from RCRA requirements, the next step is to determine if the material is a "listed waste".

  • EPA "lists" hazardous wastes that fall into four categories;

    • F-listed wastes: The F list includes wastes from common industrial processes. Because they are not specific to one type of industry, they are called wastes from non-specific sources. This list includes for example many types of spent (or used) solvents. See 40 CFR section 261.31) to see if your waste is F-listed.
    • K-listed wastes: The K list includes wastes from specific industrial processes, such as wood preservation, organic chemical production, and pesticide manufacturing. See 40 CFR 261.32 for the complete list of manufacturing process wastes to see if your facility might have a K-listed waste.
    • P- and U-listed wastes: These two lists designate certain commercial chemical products as hazardous when disposed of unused. These unused chemicals may become wastes in a number of ways. Some can be spilled while in use while others can be intentionally discarded if out of specification. For a waste to qualify as a P- or U-listed waste, it must meet all three of the following criteria:
      • The formulation must contain at least one chemical on the P or U list (see 40 CFR section 261.33)
      • The chemical in the waste must be unused
      • The chemical in the waste must be in the form of a commercial chemical product. (NOTE: A commercial chemical product is a chemical that is either 100 percent pure, technical (e.g., commercial) grade or the sole active ingredient in a chemical formulation.)

    There are hundreds of P- and U-listed wastes. Facility managers should look in 40 CFR section 261.33 to see if chemicals present on-site are hazardous if disposed of unused. Please note that the chemicals with the "P" code are acutely hazardous. Generators with acutely hazardous waste are subject to different accumulation limits for those wastes.

Is the solid waste a listed waste (F, K, P, U)?

YES - the waste is a listed waste and is therefore regulated under RCRA Subtitle C.
NO - click here to go to Step #4 below.

Step 4
#4 - Is Your Solid Waste a Characteristic Waste?
If your waste is not listed in 40 CFR Part 261, it may still be a hazardous waste. The next step is to see if your waste is a characteristic hazardous waste.

  • Solid wastes that are not directly listed in 40 CFR Part 261 may still be hazardous. EPA uses a classification system based on the four properties of solid wastes. If a material exhibits at least one of these characteristics, it is classified as a hazardous waste. The four properties are:

    • IGNITABILITY (40 CFR 261.21)
      • A liquid, other than an aqueous solution containing less than 24% by alcohol by volume with a flashpoint of less than 60° C (140° F);
      • A non-liquid that is capable, under standard temperature and pressure, of causing fire through friction, absorbtion of moisture, or spontaneous chemical changes, and when ignited, burns so vigorously and persistently that it creates a hazard;
      • An ignitable compressed gas;
      • An oxidizer (such as a chlorate or peroxide).

    • CORROSIVITY (40 CFR 261.22)
      • An aqueous material with a pH less than or equal to 2 or greater than or equal to 12.5;
      • A liquid that corrodes steel at a rate of at least 0.25 inches per year at 55° C (130° F); NOTE: A waste that is not aqueous and contains no liquid falls outside the definition of EPA corrosivity.

    • REACTIVITY (40 CFR 261.23)
      • Normally unstable and readily undergoes violent change without detonating;
      • Reacts violently with water;
      • Forms potentially explosive mixtures with water;
      • A cyanide or sulfide bearing waste which, when exposed to pH conditions between 2 and 12.5, can generate toxic gases, vapors, or fumes in a quantity sufficient to present a danger to human health or the environment
      • Capable of detonation or explosive reaction if it is subjected to a strong initiating source or if heated under confinement;
      • Readily capable of detonation or explosive decomposition or reaction at standard temperature and pressure;
      • A forbidden explosive as defined in 49 CFR 173.54, or is a Division 1.1, 1.2 or 1.3 explosive as defined in 49 CFR 173.50 and 173.53

    • TOXICITY (40 CFR 261.24)
        A substance is toxic if it exceeds the concentrations for contaminants listed in the "Maximum Concentration of Contaminants for the Toxicity Characteristic" table, presented in 40 CFR 261.24. A specific test, the Toxicity Characteristic Leaching Procedure (TCLP) must be conducted to determine if the waste is classified as toxic.

    • EPA designates specific, standardized test methods that are to be used when determining the characteristics of a waste. These techniques are listed in the above mentioned sections.

Is the solid waste a characteristic hazardous waste?

YES - the waste is a characteristic waste and is therefore regulated under RCRA Subtitle C.
NO - If you have followed Steps 1 – 4 and the answer is NO to all questions, the waste is not likely to be a hazardous waste. But, this flowchart only represents the most common issues related to identification of hazardous waste. Therefore, if there are still questions or concerns, consult your state regulator and/or the EPA guidance.

Back to Top  Page Top
Regulatory Sources
No items available.
Related Topics
No items available.
Last Updated: January 31, 2017