How To Make a Hazardous Waste Determination

If your manufacturing or industrial operations generate waste, it’s important to classify your waste correctly, or face regulatory consequences.

The rules for determining if a certain waste must be classified a “hazardous” are outlined in the Resource Conservation and Recovery Act (RCRA) and in the regulations created by the U.S. Environmental Protection Agency (EPA). Making this a challenging task is the fact that you likely  generate other types of waste as well and require different types of disposal, from universal to non-hazardous waste disposal.

A lot is at stake, from your company’s reputation to your role in protecting human health or the environment. Need to know how to make a hazardous waste determination? Here are five questions to ask:

1. Is it solid waste?
2. Is it excluded?
3. Is it listed?
4. Is it characteristic?
5. Is it a mixture?

Step 1: Is It Solid Waste?

Consult 40 CFR Part 261.2 , which provides the definition of materials that qualifies as “solid waste” and materials that do not meet the definition. The RCRA regulation (§1004(27)) provides the following definition of a “solid waste”: “Any garbage, refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility, and other discarded material, including solid, liquid, semisolid, or contained gaseous material, resulting from industrial, commercial, mining, and agricultural operations and from community activities.”

If you need assistance in answering this first question, the Definition of Solid Waste (DSW) decision tool provided by the EPA can assist you.

Remember, that the term “solid waste” does not describe the physicality of the waste. Your waste stream can be solid, liquid, or gas.

Is It Excluded?

Under CFR Title 40, Part 261.4 (b) CFR Title 40, Part 261.4 (b) , some types of solid waste are on the EPA’s list of exclusions. Consequently, even though a waste can meet the criteria of a listing or demonstrate a property of hazardous waste, you should not classify it as a hazardous waste. Some of the exclude wastes contained in CFR Title 40, Part 261.4 (b) include:

•  Household Hazardous Waste
•  Injected Groundwater
•  Agricultural Waste
•  Mining Overburden
•  Fossil Fuel Combustion Waste
•  Oil, Gas and Geothermal Wastes
•  Mining and Mineral Processing Wastes
•  Cement Kiln Dust
•  Arsenically Treated Wood
•  Spent Chlorofluorocarbon Refrigerants
•  Used Oil Filters
•  Used Oil Distillation Bottoms
•  Landfill Leachate
•  Petroleum Contaminated Media & Debris from Underground Storage Tanks

During the process of making the determination, make sure that you read the list and conditions carefully because many of the exclusions are based on certain conditions, and may apply to a specific industry or waste type. You should not proceed to Step 3, which assesses the actual chemical or physical hazard a waste presents, until you have determined that the waste is not excluded under the guidelines.

Even after you make a determination that your waste stream qualifies for an exclusion from the hazardous waste list, you should conduct periodic evaluations to verify that the current composition of you waste to ensure that it has not changed. In addition, make sure that you document any waste exclusion in your files.

Is It Listed?

The EPA has conducted research on a broad range of industries and the hazardous waste streams generated by these plants and facilities. As a result, the agency has complied four types of Listed Hazardous Waste, which you can find at 40 CFR 261, Subpart D. Here are the four listings:

• F Listed Hazardous Wastes: This list contains certain solid wastes generated by common manufacturing or industrial processes found to be hazardous. The processes producing the F list wastes span across a broad array of industrial sectors and are known as wastes from “nonspecific sources.” The regulations contained in §261.31 provide guidance on handling this type of waste material.
• K Listed Hazardous Wastes: K list wastes, commonly known as “wastes from specific sources”, can be found under §261.32.This listing differs from the F listing because it defines particular solid wastes from specific industries as hazardous.
• P and U Listed Hazardous Wastes: The P and U listings, found under §261.33, contain both pure or commercial grade formulations of certain specific unused chemicals that are hazardous to humans or the environment.

In some cases, you will determine that the waste stream is not a listed hazardous waste. When determining whether a waste stream is hazardous, sampling and testing are essential if there’s any uncertainty about its classification. 

Regulations under the Resource Conservation and Recovery Act (RCRA) require organizations to provide documented evidence demonstrating the characteristics of their waste, particularly if it may exhibit properties like ignitability, corrosivity, reactivity or toxicity. Conducting thorough testing ensures that waste streams are accurately classified, preventing the mismanagement of potentially hazardous materials and avoiding regulatory penalties. 

Proper documentation from testing also provides a clear, defensible record in case of an audit or inspection, showcasing due diligence in meeting environmental compliance standards.

Is It Characteristic?

When is comes to determining if a waste is hazardous you also need to look at the characteristics. Some mixtures of waste can be just as hazardous as a single material of waste, or they can be very benignant. That is why listing isn't always a plausible way to account for mixtures. Therefore, we have to look at the characteristics. According to RCRA, a waste must have these characteristics in order to be hazardous:

• Ignitable
• Corrosive
• Reactive
• Toxic

So, even if a waste has been classified as a listed waste, it should also be evaluated to see if it is a characteristic waste. 

Is It A Mixture?

The rules are different for characteristic and listed waste. That is why you have to look at how the waste is mixed. If you mix hazardous and non-hazardous materials then it may be classified as hazardous waste. If you have mixed listed waste then it will always result in being a hazardous waste. If you mix characteristic waste then it is only hazardous if the mixture itself has the characteristic.  

Correctly determining whether a waste stream is hazardous involves understanding the complex rules around mixtures, listed waste and characteristic waste. Remember that even if a mixture initially seems safe, regulatory requirements may still classify it as hazardous based on the type of waste combined. 

To avoid compliance issues and ensure environmentally responsible practices, regularly review your waste determinations and consult with hazardous waste professionals as needed. Proper classification, sampling and documentation help protect your operations and the environment, minimizing risk and supporting safe, lawful disposal practices. 

If in doubt, work with a certified hazardous waste disposal company to verify that every step of your waste management process aligns with federal and state regulations.