According to the EPA, RCRA, or the Resource Conservation and Recovery Act, is “the public law that creates the framework for the proper management of hazardous and non-hazardous solid waste.” The EPA continues to explain that “The law describes the waste management program mandated by Congress that gave EPA authority to develop the RCRA program. The term RCRA is often used interchangeably to refer to the law, regulations and EPA policy and guidance.”
So in effect, the acronym RCRA is used to refer to a lot of stuff related to the regulations regarding hazardous and non-hazardous solid waste.
In this article, we’ll go into more detail about the Resource Conservation and Recovery Act (RCRA) and in particular help you learn to determine what a hazardous waste is.
If your interests are broader, you may also enjoy our article that explains EPA and Environmental Regulations.
The RCRA Regulations Governing Hazardous and Non-Hazardous Solid Wastes
In 1976, the US Congress passed the Resource Conservation and Recovery Act (RCRA) to regulate “solid wastes,” including both hazardous and non-hazardous solid wastes.
Hazardous solid wastes are covered by Subtitle C of RCRA in parts 260-273. Subtitle C applies to any company that generates, transports, treats, stores, or disposes of hazardous waste. That generation-to-disposal focus is why it’s considered a “cradle to grave” treatment of hazardous wastes. It is Subtitle C and its emphasis on hazardous solid wastes that will be the focus of this article. For even more related information, check out our What Is Hazardous Waste? article.
Although this article will focus on the US federal RCRA regulation, know that most states have their own hazardous waste programs as well. In many cases, just knowing about the RCRA regulations for hazardous wastes won’t be enough.
In addition to the hazardous solid wastes covered in Subtitle C, RCRA covers non-hazardous solid wastes in Subtitle D in parts 239-258. Again, these regulations can vary depending on state and local government regulations.
There are additional legislative and administrative sections of the RCRA regulation that are perhaps of less interest to the general reader (or, at least, the kind of general reader who would choose to read an article about RCRA regulations, like yourself). You can see an entire list of the RCRA subtitles here.
What Is a Hazardous Waste According to RCRA?
Put in general terms, a waste with a chemical composition or property that makes it dangerous or potentially harmful to our health or environment is considered hazardous.
Sounds simple enough, and in some ways it is. But there’s no one simple way to determine if any waste is hazardous.
As a result, RCRA has established the following 4 steps to determine if a waste is hazardous:
- Determine if the waste is a solid waste
- Determine if the waste has been specifically excluded from RCRA
- Determine if the waste is listed as a hazardous waste
- Determine if the waste is a “characteristic” hazardous waste
We’ll explain each of the four steps below in more detail.
Step 1: Is the Waste a Solid Waste?
The first step is to determine if the waste is considered a solid waste. If it’s not a solid waste, it’s not considered a hazardous waste.
The EPA defines a solid waste as “garbage, refuse, sludge, or other discarded material (including solids, semisolids, liquids, and contained gaseous materials).”
Step 2: Is the Solid Waste Excluded from RCRA by the EPA?
The next step is to determine if the solid waste has been excluded by the EPA/RCRA.
The EPA maintains a list of “exempt” or excluded solid wastes that are not considered a hazardous waste even if they might exhibit a hazardous characteristic.
You can find more information about these solid wastes that are excluded or exempt from consideration as hazardous solid wastes here and in 40 CFR 261.4.
Step 3: Is the Waste a Listed Hazardous Waste?
If you’ve determined the waste is solid and that it’s not exempt, the next step is to determine if it’s on one of four lists the EPA manages to identify specific hazardous wastes.
These lists are based on extensive testing and they describe the wastes based on their origin (not chemical composition, for example).
There are four separate lists of specifically identified hazardous wastes: The F list, the K list, the P list, and the K list. Each are described in more detail below:
- F list–the F list identifies hazardous wastes from common manufacturing and industrial processes. These wastes come from more than just one industry sector, and as a result they’re known as “wastes from non-specific sources.” They are listed in 40 CFR section 261.31 and are in turn sub-divided into seven smaller groups, which we’ll list and explain shortly.
- K list–the K list identifies hazardous wastes that originate from specific sectors of manufacturing and industry. As a result, they’re considered “source-specific wastes.” To appear on the K list of hazardous wastes, a waste much (a) fit into one of the thirteen categories on the K list and (b) match one of the K list waste descriptions in. 40 CFR section 261.32. There are 13 industries that generate K list wastes–we’ll list and explain them more shortly.
- P list–the P list includes unused commercial chemical products that are being discarded and that are acutely hazardous. You can find the P list at 40 CFR section 261.33.
- U list–the U list includes unused commercial chemical products that are being discarded and that contain toxic constituents. You can find the U list at 40 CFR section 261.33
The EPA provides a handy, user-friendly guide to hazardous waste listings.
A Closer Look at the Four Hazardous Waste Lists
Let’s take a closer look at the four hazardous waste lists we just introduced.
The F List of Hazardous Wastes
The F-list wastes are further divided into seven different categories based on the type of manufacturing or industrial process that generates them. Remember, F-list wastes are non-source specific.
The F list categories are:
- Spent solvent wastes
- Wastes from electroplating and other metal finishing operations
- Dioxin-bearing wastes
- Wastes from chlorinated aliphatic hydrocarbon production
- Wastes from wood preserving
- Petroleum refinery wastewater treatment sludges
- Multisource leachate
The K List of Hazardous Wastes
The K list hazardous wastes come from specific industries and therefore are called source-specific hazardous wastes. The K list includes wastes from the following 12 industries:
- Wood preservation
- Organic chemical manufacturing
- Pesticides manufacturing
- Petroleum refining
- Veterinary pharmaceuticals manufacturing
- Inorganic pigment manufacturing
- Inorganic chemical manufacturing
- Explosives manufacturing
- Iron and steel production
- Primary aluminum production
- Secondary lead processing
- Ink formulation
- Coking (processing coal to produce coke)
Any facility that belongs to one of these industries must use the K list to determine if they have one of the listed hazardous wastes.
The P and U Lists of Hazardous Wastes
The P or U lists only apply if the listed chemical is unused and is being discarded.
Chemicals that are accidentally spilled or chemicals that are intentionally discarded because they cannot be used for their intended purpose are covered by the P and U lists. However, the listed chemical must be the sole active ingredient in the discarded chemical.
Four Criteria for Determining P- and U-list Wastes
There are four criteria used to determine if a waste is a P- or U-listed waste:
- Any chemical that has the generic name listed
- Any off-specification chemical, which, if it had met specifications, would have the generic name listed
- Any chemical residue remaining in a container or in a liner removed from a container that has the generic name listed
- Any contaminated soil, water, or other debris from an accidental spill of a chemical that has the generic name listed
EPA Hazardous Waste Hazard Codes
The EPA uses hazard codes in each list to designate why a waste is listed as hazardous. There are six hazard codes:
- T for Toxic Waste
- H for Acute Hazardous Waste
- I for Ignitable Waste
- C for Corrosive Waste
- R for Reactive Waste
- E for Toxicity Characteristic Waste
The hazard codes determine the regulations that apply to the waste. For example, acute hazardous wastes are considered especially dangerous because they are fatal to humans and animals at low doses, so they are subject to stricter rules.
Step 4: Does the Waste Have a Hazardous Waste Characteristic?
The EPA listings can’t list every possible hazardous waste, so step 4 is to ask if the waste has one of four hazardous waste characteristics are used as the final waste determination step.
The four characteristics that make a waste hazardous are:
You can read more about hazardous waste characteristics here.
The generator of the solid waste is responsible for determining if it hazardous. Lab testing is the best option for this, but some of the tests are very expensive. As a result, waste generators are not required to use the EPA test standards to determine if the waste displays one of these characteristics. Instead, the waste generator can use knowledge of the waste’s properties to determine this. If the waste generators goes this route, the information must be documented in a way that shows it’s valid, verifiable, and correctly applied.
The generator is responsible for determining if a waste is a RCRA hazardous waste. Laboratory testing is the best option, but some tests can be expensive, so generators are not required to use the EPA test standards for determining if the waste displays one of the characteristics. Instead of sending a sample for laboratory testing, a generator can use knowledge of the waste’s properties to determine if it possesses a hazardous characteristic. However, if relying on a knowledge-based determination, the generator must be able to clearly document that the information used is valid, verifiable, and correctly applied.
Let’s look at each of the four hazardous waste characteristics more closely.
Ignitable wastes readily catch fire and will sustain combustion.
Most ignitable wastes are liquids. To test if an ignitable waste is an ignitable hazard, use a flash point test. The flash point is the lowest temperature at which the chemical will ignite when it’s exposed to flame. If the flash point is less than 140 degrees Fahrenheit, or 60 degrees Celsius, it’s an ignitable waste.
Non-liquid wastes can be considered ignitable wastes too. This includes many compressed gases, oxidizing chemicals, and wastes that can spontaneously catch fire by friction, moisture absorption, or spontaneous chemical changes under normal atmospheric conditions.
Acids and alkalines are considered corrosive if they can readily corrode or dissolve flesh, metal, or other materials.
One simple way to test for corrosivity is to test the pH of a waste. If the pH is greater than 12.5 or less than 2, it’s corrosive.
In addition, the EPA has a specific test to determine if a waste can corrode steel.
Corrosive wastes are very common. Acidic or alkaline wastes are considered corrosive if they can readily corrode or dissolve flesh, metal, or other materials. One way to identify Corrosivity is to test the pH of liquid wastes. Wastes with a pH ≥ 12.5 or a pH ≤ 2 are considered corrosive. Also, a specific test approved by the EPA can be used to determine if the waste can corrode steel.
A reactive waste is one that can react violently or explode.
The EPA does not have a specific, reliable test to determine if a waste is reactive. Instead, the EPA offers “narrative descriptions” that define most reactive wastes.
A waste is considered to be a reactive hazardous waste if it meets any of the following criteria:
- The waste can explode or react violently when exposed to water, when heated, or under normal handling conditions
- The waste can create toxic fumes or gases when exposed to water under normal handling conditions
- The waste meets the criteria for classifications as an explosive under Department of Transportation (DOT) rules
- The waste generates toxic levels of sulfide or cyanide gas when exposed to a pH range of 2-12
It is up to the waste generators to determine if the waste is reactive enough to be hazardous.
Toxic wastes are harmful when they’re ingested or absorbed and are a particular concern when they can leach from waste and pollute nearby groundwater.
The EPA’s Toxicity Characteristic Leaching Procedure (TCLP) (SW-846 Test Method 1311) is used to test for toxicity.
After using the TCLP procedure, the liquid leachate is tested to determine the concentration of 39 different toxic chemicals (waste codes D004 through D043). If any of these chemicals is present in a concentration higher than the regulatory limit, the waste is considered hazardous.
The Mixture and Derived-From Rules
There are a few additional rules that apply to both listed and characteristic wastes you should know about. Namely the Mixture Rule and the Derived-From Rule.
We explain both for you below.
The Mixture Rule
The mixture rule states that a mixture made up of a non-hazardous solid waste and any amount of a listed hazardous waste is considered a listed hazardous waste. Even if a small amount of a listed waste is mixed with a large amount of a non-hazardous waste, the mixture is still considered hazardous.
The Derived-from Rule
The derived-from rule states that any material derived from a listed hazardous waste is also a listed hazardous waste. For example, ash from burning a listed waste is considered hazardous.
Essentially, if a waste fits a listed description, it will always be a listed hazardous waste, no matter how it is mixed, treated, or changed. Any material that comes in contact with a listed waste becomes hazardous as well, regardless of its chemical composition.
Exemptions from Mixture and Derived-from Rules
There are exemptions to the mixture and derived-from rules but they are very specific. Most cover a specific treatment process that has been extensively tested by the EPA to determine the waste is no longer hazardous.
Conclusion: What is RCRA–the EPA’s Resource Conservation and Recovery Act
We hope you found this introduction RCRA, and in particular to hazardous wastes covered by RCRA, to be helpful.
For additional information, we suggest you check out our online RCRA Introduction training course.
In addition, since RCRA covers underground storage tanks as well, you may be interested in our online Underground Storage Tanks Requirements training course.
And of course there are also these helpful articles you might enjoy:
And before you leave, please download our free guide to effective environmental, health, and safety training, which includes a lot of lessons from the ANSI Z490.1 standard and more.
Effective EHS Training: A Step-by-Step Guide
Learn how to design, create, deliver, and evaluate effective EHS training by following these best practices with our free step-by-step guide.