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Indiana Department of Environmental Management

IDEM > Compliance > Land Compliance > Auto Salvage > Auto Salvage Guidance & Resources > How to Identify Waste & Determine if It's Hazardous Waste How to Identify Waste & Determine if It's Hazardous Waste

Table of Contents

The Resource Conservation and Recovery Act of 1976 was designed to ensure that the generation, transport, treatment, storage and disposal of hazardous wastes are conducted in a manner that protects human health and the environment.

This guidance document was developed to assist you in properly identifying all wastes that you generate, treat, store or send off-site for recycling, energy recovery or disposal.

As a generator, you must:

  • Conduct proper waste analysis to determine whether your waste is defined as a hazardous waste under RCRA, and
  • Ensure that your waste is managed properly.

Waste analysis involves identifying or verifying the chemical and physical characteristics of a waste by performing a detailed chemical and physical analysis of a representative sample of the waste or, in certain cases, by applying acceptable knowledge of the waste.


What Does RCRA Hazardous Waste Determination Involve?

Step 1: Determine whether the material in question is a solid waste.

The term "solid waste" can be somewhat misleading. The word "solid" does not refer to the physical state of the waste. Solid waste can be a solid, liquid, or contained gas. Under the Resource Conservation and Recovery Act, a solid waste is any material that you will no longer be using for its originally intended purpose or a material that must be reclaimed before reuse. In order for any material to be a hazardous waste, it must first be a solid waste.


Step 2: Determine whether the waste is exempted or excluded from hazardous waste regulation.

Not all RCRA solid wastes are considered hazardous wastes. The U.S. Environmental Protection Agency exempted or excluded certain wastes, such as household wastes or used oil destined for recycling, from the hazardous waste definition and regulation. Don't proceed to Step 3, which is evaluating the actual chemical or physical hazard a waste poses, until you've determined the waste is not somehow excluded from hazardous waste regulation.

Note: Even if you've determined your waste is excluded from hazardous waste regulation, you need to re-evaluate your status periodically to verify that conditions affecting the composition of your waste have not changed.


Step 3: Determine whether the waste actually poses a sufficient chemical or physical hazard to merit regulation. This step involves evaluating the waste in light of the regulatory definition of hazardous waste.

If you find your waste is not exempted or excluded from hazardous waste regulation, you must determine if the waste meets one or more of the hazardous waste listing descriptions found in 40 CFR Part 261 Subpart D.

F-listed wastes
40 CFR 261.31 lists hazardous wastes from non-specific sources (termed "F-listed wastes" after the F prefix in this hazardous waste code). An example would include F002 wastes-spent halogenated solvents (e.g., pechloroethylene, trichloroethylene, methylene chloride).
K-listed wastes
40 CFR 261.32 lists hazardous wastes from specific sources, such as K062 waste-spent pickle liquor generated by steel finishing operations of facilities within the iron and steel industry.
P- and U-listed wastes
40 CFR 261.33 lists discarded or unused commercial chemical products, off-specification products, container residues and spill residues of such products.

If the waste is not listed, you must determine if the waste meets one or more of the hazardous waste listing descriptions found in 40 CFR Part 261 Subpart D.

A waste is ignitable if it is a liquid and its flash point is less than 140° F (60° C). A waste also may be defined as ignitable if it is an oxidizer or an ignitable compressed gas as defined by the U.S. Department of Transportation Regulations in 49 CFR Part 173, or if it has the potential to ignite under standard temperature and pressure and burn persistently and vigouously once ignited. Wastes that are ignitable are classified as U.S. EPA Hazardous Waste Code D001. Examples of ignitable wastes include certain spent solvents such as mineral spirits.
A waste is corrosive if it is aqueous and its pH is less than or equal to 2 or greater than or equal to 12.5. A waste also is corrosive if it is a liquid and it corrodes steel at a rate of more than 0.25 inches per year under conditions specified in U.S. EPA Test Method 1110. Corrosive wastes are designated as U.S. EPA Hazardous Waste Code D002. Examples of corrosive wastes include spent sulfuric acid and concentrated waste sodium hydroxide solutions that have not been neutralized.
A waste exhibits reactivity if it is unstable and explodes or produces fumes, gases, and vapors when mixed with water or under other conditions such as heat or pressure. A waste also may be defined as reactive if it is a forbidden explosive or a Class A or Class B explosive as defined in 49 CFR Part 173. Wastes that exhibit the characteristic of reactivity are classified as U.S. EPA Hazardous Waste Code D003. Examples of reactive wastes include certain cyanide or sulfide-bearing wastes.
The toxicity characteristic of a waste is determined by having a laboratory analyze an extract of the waste using the Toxicity Characteristic Leaching Procedure. The results of the analysis are compared to the regulatory thresholds of 40 constituents, primarily metals, organic compounds, and pesticides/herbicides. If the extract from the TCLP contains levels of any of the 40 constituents at or above regulatory thresholds, the waste is considered a hazardous waste. Wastes that exhibit the toxicity characteristic are classified as U.S. EPA Hazardous Waste Codes D004 through D043. Examples of toxic wastes may include wastewater treatment sludges, wastes from organic chemical manufacturing and pesticide/herbicide wastes.


Conduct Waste Sampling and Analysis

You can meet general waste analysis requirements using several methods or combinations of methods. The preferred method is to conduct sampling and analysis of the waste because this method is more accurate and defensible than other options. Procedures and equipment for obtaining and analyzing samples are described in Appendices I and II of 40 CFR Part 261. Full-scale analysis that uses methods from U.S. EPA's "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods" SW-846, 3rd Edition or equivalent, may be necessary when:

  • You begin a new process or change and existing one;
  • You have not provided appropriate laboratory information to an off-site treatment, storage and disposal facility;
  • An off-site TSDF has reason to believe the wastes you shipped were not identified accurately;
  • U.S. EPA amends RCRA waste identification/classification rules and/or;
  • A facility receives your waste for the first time.

IDEM recommends that you prepare a sampling and analysis plan prior to sample collection and testing. Chapters 1 and 9 of "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods" SW-846, 3rd Edition, are excellent sources of information on sampling and analysis.

To properly characterize a waste, analysis of a representative sample from each waste stream is required. Methods for statistical determination of a valid number of samples, recommended sampling methods, sampling strategies and applicable sampling equipment also can be found in Chapter 9.

A representative sample is defined as a sample of a universe or whole that can be expected to exhibit the average properties of the universe or whole.


Apply Generator Knowledge of the Process or Materials that Produced the Waste

You also can meet waste analysis requirements by applying knowledge of the waste. Generator knowledge can be used to meet all or part of the waste analysis requirements and can be defined broadly to include "process knowledge." Process knowledge may be information on the wastes obtained from existing published or documented waste analysis data or studies conducted on hazardous wastes generated by processes similar to that which generated your waste. For example, listed wastes are identified by comparing the specific process that generated your waste to those processes described in the listings rather than conducting a chemical/physical analysis of the waste. Therefore, with many listed wastes, generator knowledge is appropriate because the physical/chemical makeup of the waste is generally well-known and consistent from facility to facility.

Note: The use of existing or historical records of analysis seems attractive, as opposed to sampling and analysis, because of the potential savings associated with using such information. However, you must ensure this information reflects the current processes and materials being used and that no differences exist between the process in the documented data and your own.

If you use generator knowledge alone or in conjunction with sampling and analysis, you must maintain detailed documentation that clearly demonstrates the information is sufficient to identify the waste. Documenting both the generator knowledge and any analytical data is essential. Documentation used to support generator knowledge may include, but is not limited to:

  • Material safety data sheets or similar documents,
  • A thorough process description, including data on all raw materials used in the process, and or
  • Other forms of detailed documentation.

Note: Concerning MSDSs, manufacturers/suppliers are only required to list constituents that comprise 1% or more of the material it addresses. This level of reporting may not be adequate to ascertain the constituent levels in the wastes to be characterized. Therefore, MSDSs should be viewed in a supporting fashion and not as the sole means of providing generator knowledge.



Although IDEM recognizes that sampling and analysis are not as economical or convenient as using generator knowledge, they usually provide advantages. Because accurate waste determination is such a critical factor for demonstrating compliance with the Resource Conservation and Recovery Act, misidentification can render your facility liable for enforcement actions with respect to permit conditions, land disposal restriction requirements, annual reporting, and other RCRA requirements. In addition, accurate waste analysis is critical for meeting some of the requirements of other regulatory programs such as effluent discharges under the Clean Water Act, transportation requirements administered by the Department of Transportation and special waste classification procedures. Be sure to:

  1. Keep current with the latest regulatory developments in the RCRA program that may affect the classification of your waste; and
  2. Re-evaluate your wastes frequently using current analytical methods and/or process knowledge, particularly any time a rule affecting RCRA waste identification is finalized.


For More Information

If you have any questions about your waste determination responsibilities, call the Compliance and Response Branch of IDEM's Office of Land Quality at (800) 451-6027, ext. 308-3103.

IDEM Switchboard/Enviroline: (800) 451-6027 or (317) 232-8603
Indiana Department of Transportation: (317) 232-3166
Office of Air Management: (317) 233-0178
Office of Water Management: (317) 232-8670
U.S. U.S. EPA Region V Information: (800) 621-8431