Derived-from rule

The management or disposal of metals and ash, other by-products of the combustion process, also causes concern. Ash is an inert solid material composed primarily of carbon, salts, and metals. During combustion, most ash collects at the bottom of the combustion chamber (bottom ash). When this ash is removed from the combustion chamber, it may be considered hazardous waste via the derived-from rule or because it exhibits a characteristic. Small particles of ash (particulate matter that may also have metals attached), however, may be carried up the stack with the gases (fly ash). These particles and associated metals are also regulated by the combustion regulations, as they may carry hazardous constituents out of the unit and into the atmosphere. Since combustion will not destroy inorganic compounds present in hazardous waste, such as metals, it is possible that such... 

Residues from the combustion of hazardous waste are also potentially subject to RCRA regulation. If a combustion unit bums a listed hazardous waste, the ash could also be considered a listed waste via the derived-from rule. The owner and operator must also determine whether this ash exhibits any hazardous waste characteristics. The same is true if a unit bums waste that only exhibits a characteristic. Ash that exhibits a characteristic must be managed as a hazardous waste. 

So far, this chapter has introduced the fundamentals of the hazardous waste identification process and an overview of the hazardous waste listings and characteristics. One should now be able to explain in general terms which solid wastes are hazardous wastes. What remains to be explained is when these hazardous wastes cease being regulated as hazardous wastes. The regulations governing this issue are commonly known as the mixture and derived-from rules. 

The net effect of the mixture and derived-from rules for listed wastes can be summarized as follows once a waste matches a listing description, it is forever a listed hazardous waste, regardless... 

The mixture and derived-from rules apply differently to listed and characteristic wastes. A mixture involving characteristic wastes is hazardous only if the mixture itself exhibits a characteristic. Similarly, treatment residues and materials derived from characteristic wastes are hazardous only if they themselves exhibit a characteristic. Unlike listed hazardous wastes, characteristic wastes are hazardous because they possess one of four unique and measurable properties. U.S. EPA decided that once a characteristic waste no longer exhibits one of these four dangerous properties, it no longer deserves regulation as hazardous. Thus, a characteristic waste can be made nonhazardous by treating it to remove its hazardous property however, U.S. EPA places certain restrictions on the manner in which a waste can be treated. One can learn more about these restrictions in the U.S. EPA Land Disposal Restrictions Module Handlers who render characteristic wastes nonhazardous must consider these restrictions when treating wastes to remove their hazardous properties. 

There are a few situations in which U.S. EPA does not require strict application of the mixture and derived-from rules. U.S. EPA determined that certain mixtures involving listed wastes and certain residues from the treatment of listed wastes typically do not pose enough of a health or environmental threat to deserve regulation as listed wastes. The principal regulatory exclusions from the mixture and derived-from rules are summarized below. 

There are five regulatory exemptions from the derived-from rule. The first of these derived-from rule exemptions applies to materials that are reclaimed from hazardous wastes and used beneficially. Many listed and characteristic hazardous wastes can be recycled to make new products or be processed to recover useable materials with economic value. Such products derived from recycled hazardous wastes are no longer solid wastes. Using the hazardous waste identification process discussed at the beginning of this chapter, if the materials are not solid wastes, then whether they are derived from listed wastes or whether they exhibit hazardous characteristics is irrelevant. A U.S. EPA module10 explains which residues derived from hazardous wastes cease to be wastes and qualify for this exemption. 

The hazardous waste listings, the hazardous waste characteristics, and the mixture and derived-from rules are all essential parts of the definition of hazardous waste, but these key elements are all described in different sections of the RCRA regulations. Only one regulatory section unites all four elements to establish the formal definition of hazardous waste. This section is entitled Definition of Hazardous Waste, which states that all solid wastes exhibiting one of the four hazardous characteristics are hazardous wastes. This section also states that all solid wastes listed on one of the four hazardous waste lists are hazardous wastes. Finally, this section explains in detail the mixture and derived-from rules and the regulatory exemptions from these rules. Thus, although the section is entitled Definition of Hazardous Waste, it serves primarily as a guide to the mixture and derived-from rules. 

The contained-in policy is a special, more flexible version of the mixture and derived-from rules that applies to environmental media and debris contaminated with hazardous waste. Environmental media is the term U.S. EPA uses to describe soil, sediments, and groundwater. Debris is a term U.S. EPA uses to describe a broad category of larger manufactured and naturally occurring objects that are commonly discarded. Examples of debris include the following ... 

U.S. EPA proposed to significantly impact the RCRA hazardous waste identification process through a rulemaking effort called the Hazardous Waste Identification Rules (H WIR). The first rule, HWIR-media, was finalized on November 30,1998, and addressed contaminated media.16 The second rule, HWIR-waste, was finalized on May 16, 2001, and modified the mixture and derived-from rules, as well as the contained-in policy for listed wastes.5 Both the HWIR-media rule and the HWIR-waste rule attempt to increase flexibility in the hazardous waste identification system by providing a regulatory mechanism for certain hazardous wastes with low concentrations of hazardous constituents to exit the RCRA Subtitle C universe. 

On July 18, 2000, the Agency released HWIR-waste exemption levels for 36 chemicals that were developed using a risk model known as the Multimedia, Multi-pathway and Multi-receptor Risk Assessment (3MRA) Model.17 The May 16, 2001, HWIR-waste rule revised and retained the hazardous waste mixture and derived-from rules as previously discussed in this module. In addition, the rule finalized provisions that conditionally exempt mixed waste (waste that is both radioactive and hazardous), if the mixed waste meets certain conditions in the rule.5... 

If an incinerator burns a listed hazardous waste, the ash is also considered a listed waste. The derived-from rule states that any solid waste generated from the treatment, storage, or disposal of a listed hazardous waste, including any sludge, spill residue, ash, emission control dust, or leachate, remains a hazardous waste unless and until it is delisted. The owner/operator must also determine whether the ash exhibits any of the characteristics of a hazardous waste. 

Under the traditional hazardous waste regulations, the derived-from rule requires that anything... 

There are four lists of hazardous wastes in the regulations wastes from nonspecific sources (F list), wastes from specific sources (K list), acutely toxic wastes (P list), and toxic wastes (U list) there are also the four characteristics mentioned before ignitability, corrosivity, reactivity, and extraction procedure toxicity. Certain waste materials are excluded from regulation under the RCRA. The various definitions and situations that allow waste to be exempted can be confusing and difficult to interpret. One such case is the interpretation of the mixture and derived-from rules. According to the mixture rule, mixtures of solid waste and listed hazardous wastes are, by definition, considered hazardous. Similarly, the derived-from rule defines solid waste resulting from the management of hazardous waste to be hazardous (40 CFR 261.3a and 40 CFR 261.1c). 

There are five specific listed hazardous wastes (K list) generated in refineries, K048 to K052. Additional listed wastes, those from nonspecific sources (F list) and those from the commercial chemical product lists (P and U), may also be generated at refineries. Because of the mixture and derived-from rules, special care must be taken to ensure that hazardous wastes do not contaminate nonhazardous waste. Under the mixture rule, adding one drop of hazardous waste in a container of nonhazardous materials makes the entire container contents a hazardous waste. 

As an example of the problems such mixing can cause, consider the case with API separator sludge that is a listed hazardous waste (K051). The wastewater from a properly operating API separator is not hazardous unless it exhibits one of the characteristics of a hazardous waste. That is, the derived-from rule does not apply to the wastewater. However, if the API separator is not functioning... 

Listed" waste is any waste that contains a substance that is "listed" by the USEPA as hazardous. This type of waste has been listed based on the waste s "toxicity, persistence, and degradability in nature, potential for accumulation in tissue, and other related factors such as flammability, corrosiveness, and other hazard characteristic." Rules have been developed by the USEPA to ensure proper disposal of these types of hazardous waste. The mixture rule states that any substance mixed with a "listed" hazardous waste becomes a hazardous waste. If it is not a "listed" waste, but instead a characteristic waste, and the mixture does not exhibit any of the characteristics, the mixture is not considered hazardous. The "derived from" rule states that any waste derived from the treatment of a "listed" hazardous waste remains a hazardous waste. Similar to the mixture rule, if the by-product of a characteristic waste does not exhibit any of the hazardous characteristics, it is not considered hazardous. 

An additional constraint under RCRA that would need to be addressed in implementing the waste classification system presented in this Report involves solid waste that is identified as hazardous by listing (see Section 4.2.1). At the present time, any solid waste that is hazardous by listing cannot be rendered nonhazardous by treatment. Rather, in accordance with the mixture and derived-from rules in 40 CFR Part 261 (EPA, 1980b 1992c 2001b), any listed waste is considered to be hazardous regardless of the concentrations of listed hazardous substances, unless the waste is specifically delisted. The waste classification system developed in this Report, which includes an exempt class of waste as an essential element, could be implemented only if these rules were revised to allow establishment of exemption levels for listed hazardous chemical wastes. 

EPA (1992c). U.S. Environmental Protection Agency. 40 CFR Part 261— Hazardous waste management system definition of hazardous waste mixture and derived-from rules, Interim final rule, 57 FR 7628 (U.S. Government Printing Office, Washington). 

Based on the derived-from rule, items such as PPE are normally incinerated since these contaminated materials carry the same EPA waste codes as the waste with which they came into contact. However, on-site incineration is often done as a matter of convenience rather than because of specific risk assessments or regulatory requirements. 

Rarely will a single adsorbent be optimal in all of these respects. Frequently it will be possible to narrow the choice to one or two classes of adsorbents, leaving a vast array of possible particle sizes, shapes, pretreatment conditions, and so forth. Final decisions should always be based on data. To make budget estimates, however, a number of different approaches can be derived from rules of thumb to provide quick experimental feasibility tests. Potential sources of such information are adsorbent or equipment vendors, published or commercial databases, and in-house or external laboratories. 

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