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In the United States, hazardous wastes are subject to regulations mandated by the Resource Conservation and Recovery Act (RCRA). Every month, we provide clear, in-depth guidance on a different aspect of the RCRA regulations. The information presented here is an excerpt from McCoy’s RCRA Unraveled, 2020 Edition.

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A solid waste exhibits the toxicity characteristic (TC) if the extract (obtained using the toxicity characteristic leaching procedure or TCLP) from a representative sample of the waste contains any of the TC constituents identified in §261.24 Table 1 at a concentration greater than or equal to the applicable regulatory level (also given in that section). Forty TC constituents are listed in §261.24, including eight heavy metals, six pesticides, and 26 solvents and other organics. Because many of the TC constituents are commonly found in industrial wastes (e.g., benzene, chromium, lead, mercury, methyl ethyl ketone, silver, vinyl chloride), large quantities of solid wastes generated in this country exhibit the characteristic of toxicity. Although there may be many chemicals other than the 40 included in §261.24 that are toxic to human health and the environment, only those 40 make up the TC in the federal RCRA regulations. State programs may be more stringent, however, and some states (e.g., California) have added other constituents to their state toxicity definition.

TCLP-based toxicity determinations

The TCLP is the test we use today to determine toxicity and is included as Method 1311 in SW–846. Briefly, for wastes containing greater than or equal to 0.5% filterable solids, the lab performing the TCLP separates the liquid (if any) from the solids in the representative sample. The solids are then extracted (leached) by adding acetic acid in an amount equal to 20 times as much, by weight, as the weight of the solids portion of the sample. The extraction vessel holding the solids and acid is tumbled for 18 hours, after which the acidic extract (leachate) is separated from the solids by filtration. If compatible, the liquid initially separated from the solids is combined with the acidic extract, and the mixture is then analyzed for total concentrations of the 40 constituents in §261.24. If the two liquid streams are incompatible, they are analyzed separately, the results are mathematically combined, and the resulting volume-weighted total concentrations are compared to the regulatory levels.

For wastes that contain less than 0.5% filterable solids (e.g., wastewater), the waste itself (after filtering using the procedures outlined in the TCLP) is considered the extract and directly analyzed for total concentration of toxic constituents—no extraction (i.e., leaching with acetic acid) is necessary.

After the TCLP was promulgated, several concerns cropped up as industry began using the new method.


One of the most significant obstacles to using the TCLP is cost. Our experience indicates that a lab will charge $700–$1,500 to run the TCLP when testing for all 40 constituents. The cost is reduced considerably if you ask the lab to evaluate a sample for only a subset of the 40 TC constituents (such as the metals). But the test, in general, is relatively expensive.


Another concern with the TCLP is its reproducibility. From a scientific standpoint, the method is not very precise. While EPA was in the process of modifying the TC to incorporate the TCLP, an intergovernmental cooperative program was undertaken to evaluate the reproducibility of the test. Three different laboratories were given samples from the same batch of five discrete waste types. Within a given laboratory, the TCLP was performed on two to six replicate samples of each waste.

Data from the three laboratories indicated that 67% of the TCLP results for metals were reproducible and 13% were marginally reproducible. For the nonmetals, 60% of the results were considered reproducible. Some of the results for certain contaminants were reproducible within a given laboratory but not among the three laboratories.

These results were reported by personnel from the U.S. Army Engineer Waterways Experiment Station in 1990. The paper, “Reproducibility of Toxicity Characteristic Leaching Procedure” by Teresa T. Holmes et al., appeared in Proceedings of the 7th National Conference on Hazardous Wastes and Hazardous Materials.

Analyzing the extract

When the extract produced from the TCLP is analyzed for the 40 constituents listed in Table 1 of §261.24, what test methods have to be used? According to EPA, “the extract obtained from the TCLP may be analyzed by any method as long as that method has documented quality control and the method is sensitive enough to meet the regulatory limit. In other words, the lab does not have to use SW–846 methods [to analyze the extract for TC constituents] because these methods are intended to serve only as guidance for the regulated community.” [RO 11568; see also RO 11579, 11649]

However, the agency noted that the following EPA test methods could be used to analyze the extract [EPA/530/R-12/001, Appendix A]:

  • Methods 3010 and 6010 for arsenic, barium, cadmium, chromium, lead, silver, and selenium;
  • Method 7470 for mercury;
  • Methods 3510 and 8081 for pesticides;
  • Method 8151 for herbicides;
  • Methods 5030 and 8260 for volatile organics; and
  • Methods 3510 and 8270 for semivolatile organics.

Oily wastes and organic liquids pose problems

Many problems have been reported when laboratories have attempted to run the TCLP on oily wastes and organic liquids. In some situations, analysis of TCLP extracts has resulted in detection limits above regulatory levels. This typically happens when an organic liquid waste passes through the initial filtering stage and is, by EPA definition, a liquid and therefore its own extract (i.e., no acid extraction is required). The analysis of this liquid extract for organics entails diluting it before injection into a gas chromatograph or mass spectrometer. The dilution often results in detection limits being higher than regulatory thresholds. [RO 11579, 11592, 11627] In these circumstances, it is not possible to determine conclusively whether the waste is hazardous or not.

In addition to the detection limit problems, oily wastes have also caused premature filter clogging, emulsion formation, and difficulty in estimating percent solids. [RO 11721] EPA acknowledges that the TCLP was not intended to be applied to certain matrices, such as oils or neat solvents, and is investigating ways to solve these problems. [RO 11579, 11592]

Sample holding times

In order to ensure that accurate results are obtained from the TCLP, EPA specifies quality control measures (including sample holding times) in Method 1311. Sample holding time is the storage time allowed between field collection of a sample and completion of the laboratory analysis. [RO 11306, 13589] It is an important parameter because certain constituents, such as volatile organic compounds, can degrade or volatilize over time.

The sample holding times that EPA specifies for TCLP extraction and analysis are given in Section 8.5 of Method 1311. When these sample holding times are exceeded, the analytical results may be invalid or inconclusive because constituent levels of volatiles in expired samples may be lower than if the samples were fresh.

Analytical results obtained if sample holding times are exceeded may still have some use. For instance, if TCLP results from samples that exceeded specified holding times indicate that the concentrations of one or more TC constituents are above the applicable regulatory threshold, then those concentrations can be treated as minimum values, and the waste can be determined to be hazardous via toxicity. No additional testing is necessary. However, if the results from an expired sample reveal concentrations that are below the regulatory thresholds, further testing may be necessary to demonstrate that the waste is not toxic. [RO 13612]

TCLP not valid for manufactured gas plant wastes

EPA’s application of the TCLP to manufactured gas plant (MGP) wastes was successfully challenged in court [Association of Battery Recyclers, Inc. et al. v. EPA, 208 F.3d 1047 (2000)]. The basis of the court challenge was that MGP wastes are not managed in municipal solid waste landfills, which was the disposal scenario that serves as the basis for the TCLP. EPA has determined that, under the court’s opinion, the TCLP cannot be applied to MGP wastes; therefore, these wastes (which are not listed) are hazardous only if they exhibit any of the ignitability, corrosivity, or reactivity characteristics. Because MGP remediation wastes are unlikely to exhibit any of these characteristics, they are typically not RCRA hazardous wastes unless otherwise regulated under state authority. [RO 14491, 14492]

Knowledge-based toxicity determinations

If a generator does not run the TCLP to determine toxicity, the other option is to use knowledge. For example, the generator can use material balances and/or knowledge of the raw materials and the processes that generated the waste to make a toxicity determination. If a generator has good knowledge that a certain waste would pass or fail the TCLP, no testing is necessary. An example is the U.S. Army managing waste munitions as toxic for lead and/or 2,4-dinitrotoluene; the service didn’t want to perform the TCLP because of the inherent safety problems associated with the method’s particle-size reduction criteria. The Army could simply declare the waste to be hazardous for toxicity and manage it as such. [RO 11608, 13472] When available knowledge is inadequate to make an accurate determination, the waste must be tested. [§262.11(d)(2)] Where no information or knowledge is available to assist a generator, or when TCLP results are not available or are inconclusive, the agency noted that it might be prudent for the generator to manage the waste as hazardous. [RO 11579, 11592]

Another source of knowledge, especially for products that will be discarded, is chemical composition data on safety data sheets (SDSs). However, be advised that SDSs are not always an appropriate reference for determining if a material exhibits the toxicity characteristic. The OSHA regs, as modified to reflect the provisions of the United Nations Globally Harmonized System of Classification and Labeling of Chemicals, generally require manufacturers to identify constituents present in the material at concentrations >1% (10,000 ppm) for noncarcinogens or >0.1% (1,000 ppm) for carcinogenic constituents. [Appendix A to 29 CFR 1910.1200] Therefore, the product might contain toxicity characteristic constituents above RCRA regulatory levels even though they are not identified on the SDS.

Sometimes, a generator will use a combination of the two approaches; that is, if the generator has knowledge that certain TC constituents could not be present in the waste, the TCLP will have to be performed only for the other constituents that could possibly be in the material. [EPA/530/R-93/007, RO 11603, 14695]

A test method other than the TCLP can be used that may be more appropriate for determining the toxicity of the waste matrix. For example, the oily waste extraction procedure (OWEP—Method 1330 in SW–846) can be used to evaluate metal concentrations in oily sludges, slop oil emulsions, and other oily wastes (although this method is typically used only in support of delisting petitions). This method was developed for wastes containing oil or grease in concentrations of 1% or greater. [RO 11522, 12450]

The generator can also use total waste analyses as an alternative to TCLP results.

Total waste analyses in lieu of TCLP results

Section 1.2 of the TCLP states that “[i]f a total analysis of the waste demonstrates that individual analytes are not present in the waste, or that they are present but at such low concentrations that the appropriate regulatory levels could not possibly be exceeded, the TCLP need not be run.” Therefore, while the TCLP is typically performed to make a TC determination, a generator can alternatively use total waste analyses to determine that a waste does not exhibit the TC. A total waste analysis is also a convenient and cost-effective screening tool for determining if a TCLP is needed.

The methodology for using total waste analyses to make a TC determination varies depending on the type of waste [RO 11721, 13563, 13647, 14533, 14695]:

  • Liquids—Liquids (i.e., wastes that contain less than 0.5% filterable solids) do not require extraction. Instead, per the last sentence in §261.24(a), a generator can characterize such a liquid waste by filtering it, analyzing the total constituent concentrations in the resulting filtrate, and comparing those concentrations directly to regulatory levels.
  • Solids—For wastes that are 100% physical solids (i.e., they contain no filterable liquid), the total concentrations of the 40 TC constituents are determined, and then these total levels are converted to the maximum theoretical leachate concentrations that could possibly result from performing the TCLP. This is accomplished by dividing each total constituent concentration by 20 (reflecting the 20 to 1 weight ratio of extraction fluid to solid in the TCLP) and then comparing the resulting maximum theoretical leachate concentration to the applicable regulatory level. “If no maximum theoretical leachate concentration equals or exceeds the appropriate regulatory limit, the solid cannot exhibit the toxicity characteristic and the TCLP need not be run.” [RO 13647]

For example, a facility wants to know if chromium-containing soil that is going to be excavated and sent offsite is hazardous for toxicity. A representative sample of the soil is sent to a lab, but instead of asking the lab to perform a TCLP for metals (which would cost a couple hundred dollars), the facility asks the lab to run a total chromium analysis (which costs about $30). The lab would probably use either atomic absorption (AA) or inductively-coupled plasma (ICP) methods to determine total chromium concentration in the soil, which is measured at 50 mg/kg. Dividing that concentration by 20 gives a maximum theoretical leachate concentration for chromium in the soil of 2.5 mg/L. (That is, if 100% of the total chromium leaches via the TCLP, it would have been measured in the extract at 2.5 mg/L.) The facility can conclude that the soil cannot exhibit the TC for chromium (chromium’s regulatory level is 5.0 mg/L), because even if all of the chromium leaches during a TCLP analysis, not enough chromium is present to make the soil hazardous.

What if the total chromium concentration measured by the lab was 140 mg/kg? Again dividing by 20 gives a new maximum theoretical leachate concentration of 7.0 mg/L. Since this value is greater than the regulatory level, does the facility conclude that all of the soil is hazardous? No; the facility concludes that now it is worth spending the money to have the lab run the TCLP. [RO 14533] Our experience indicates that significant percentages of chromium and other heavy metals in soil will not leach in the TCLP.

This is why some generators send samples of wastes to a lab with the following instructions: Run a total analysis first. If the resulting total concentrations are less than 20 times the TC regulatory levels, stop. Conversely, if total concentrations are greater than or equal to 20 times the TC regulatory levels, run the TCLP.

Sometimes people ask: “If total concentrations divided by 20 are greater than or equal to TC regulatory levels for a 100% physical solid, why would you ask the lab to run the TCLP—couldn’t you just use the total concentration results and classify this waste as hazardous?” You could do that, but it would be very conservative. For example, depending on the contaminant and waste matrix, it is often the case that less than 20% of the total concentration of a contaminant will leach out during the TCLP test. The “Rule of Twenty” can be used to prove that a material is not a TC hazardous waste, or it can also be used as a screen to determine when the TCLP needs to be run. Either way, it is a useful tool for generators, enabling them to save time and money when making TC determinations.

  • Dual-phase wastes—The generator of a dual-phase waste (a waste that has both a solid and a filterable-liquid component) can perform a total waste analysis on both the solid and liquid portions and calculate maximum theoretical leachate concentrations for the waste as a whole. This is accomplished by combining results mathematically through use of the following formula:


A = Total concentration of the analyte in the liquid portion of the sample (mg/L),

B = Volume of the liquid portion of the sample (L),

C = Total concentration of the analyte in the solid portion of the sample (mg/kg),

D = Weight of the solid portion of the sample (kg), and

M = Maximum theoretical leachate concentration (mg/L).

An example of the use of this equation is given in Case Study 1.

This method may also be used for nonaqueous wastes (e.g., oily wastes). If this approach is used for such wastes, the concentration of constituents in the liquid portion of the waste (A) may be expressed in mg/kg instead of mg/L; if that is true, the liquid volume (B) would have to be converted to kg, and the final leachate concentration would be expressed in mg/kg. [RO 11721]

Case Study 1

Exemptions from the TC

Even though a waste fails the TCLP, it may not be subject to hazardous waste regulation. Examples of some of the most significant exclusions and exemptions that may apply to wastes exhibiting the TC are summarized below.

  • Lead-based paint waste from residences—Residential lead-based paint waste is defined as waste “generated as a result of activities such as abatement, rehabilitation, renovation and remodeling in homes and other residences. The term residential lead-based paint waste includes, but is not limited to, lead-based paint debris, chips, dust, and sludges.” [40 CFR 258.2] These wastes may be disposed in municipal solid waste landfills and construction and demolition waste landfills under the household waste exclusion of §261.4(b)(1). The exclusion is available to both contractors and do-it-yourselfers that generate and dispose lead-based paint wastes. [October 23, 2001; 66 FR 53537, RO 14459, 14673]
  • Trivalent chromium wastes—For purposes of determining toxicity of wastes containing chromium (D007), the TC level is based on total chromium. However, EPA acknowledged there is a significant difference in the relative hazard of the two major valences of chromium, trivalent chromium and hexavalent chromium. Trivalent chromium is much less toxic than hexavalent chromium; but, trivalent chromium can be oxidized to the more toxic hexavalent form. With this in mind, EPA developed a conditional exclusion in §261.4(b)(6) for wastes that are exclusively (or nearly exclusively) hazardous due to trivalent chromium only. The exclusion is for wastes that are characteristic for chromium only, or wastes that are listed due to the presence of chromium only. [October 30, 1980; 45 FR 72035] The exclusion applies to wastes from the leather tanning and finishing industry and to wastewater treatment sludge from a titanium dioxide (TiO2) pigment manufacturing process. These wastes are generated in processes that exclusively (or nearly exclusively) use trivalent chromium. The wastes are routinely managed in non-oxidizing environments (e.g., landfills, deep wells) which preclude the formation of the more toxic hexavalent chromium in the waste. Only the wastes identified in §261.4(b)(6)(ii)(A–H) are clearly eligible for this exclusion and the provisions of §261.4(b)(6)(i)(A–C) must be satisfied. [RO 11319, 14655] However, EPA guidance in RO 14733 indicates the exclusion may apply to other wastes that aren’t specifically identified in §261.4(b)(6)(ii)]. See Case Study 2.
Case Study 2
  • Petroleum-contaminated media and debris—Media (soil and ground water) and debris resulting from the cleanup of petroleum underground storage tanks (USTs) are excluded from the definition of hazardous waste, even if they exhibit the TC. [§261.4(b)(10)] This exclusion applies if the media and debris 1) exhibit the TC for D018–D043 only, and 2) are subject to the corrective action requirements in 40 CFR Part 280 of the UST regulations. The exclusion was promulgated to prevent the large quantities of benzene-contaminated soil at old gas stations from overwhelming the commercial hazardous waste management capacity in the United States. The exclusion does not apply if the media or debris exhibit any characteristic other than D018–D043 or have become contaminated with a listed hazardous waste. [RO 11569]
  • Used chlorofluorocarbon refrigerants—When chlorofluorocarbons (CFCs or Freon) are removed from refrigeration or air conditioning systems, they are usually considered spent materials. Such materials are solid wastes when they are reclaimed [see Table 1 in §261.2(c)], unless excluded under §261.4(a)(23–25). Spent CFCs can exhibit the TC due to the small amounts of carbon tetrachloride (D019) or chloroform (D022) contaminants often found in them. Since spent materials that exhibit the TC may require hazardous waste management (e.g., manifesting) even if they are reclaimed, EPA was concerned that these requirements would provide a disincentive for people to recycle the CFCs—instead, they would just vent them to the atmosphere. To remove such a disincentive, an exclusion in §261.4(b)(12) allows nonhazardous management of these materials, but it applies only if the CFCs will be reclaimed for reuse. This exclusion also applies to hydrochlorofluorocarbons (HCFCs) but not to hydrofluorocarbons (HFCs). [February 13, 1991; 56 FR 5911–3, RO 14323] CFCs used as refrigerants are typically not subject to the F001–F005 spent solvent listings because, as refrigerants, the CFCs are not used as solvents. [54 FR 31336]
  • Scrap metal that is recycled—Scrap metal that is recycled is exempt from hazardous waste regulation at its point of generation. [§261.6(a)(3)(ii)] For example, scrap metal that exhibits the TC does not need to be managed as a hazardous waste before it reaches the reclamation facility (e.g., manifests are not required). However, if the scrap metal is not reclaimed (e.g., if it is disposed), the exemption does not apply, and the scrap metal “remains subject to all applicable hazardous waste regulations from the point of generation. Only if the facility ensures that the material will be reclaimed will the hazardous waste regulations not apply.” [RO 14277] According to EPA, unprocessed, spent (i.e., used) printed circuit boards qualify for the scrap metal exemption. [RO 11689]
  • PCB dielectric fluids and the electrical equipment in which they are contained—Polychlorinated biphenyls (PCBs) will not, by themselves, fail the TCLP. However, chlorobenzene, which is a degradation by-product contained within these materials, will sometimes cause them to exhibit the TC as D021. Thus, such materials, when they become wastes, would be regulated as both a toxic material under the Toxic Substances Control Act (TSCA) and a hazardous waste under RCRA. To avoid such dual regulation of PCB wastes, EPA established an exemption at §261.8 from RCRA regulation for PCB fluids themselves and the electrical equipment in which they are contained. The exemption is based on compliance with two criteria: 1) the waste must be regulated under TSCA (40 CFR Part 761) in order to escape RCRA, and 2) the waste must be hazardous only because it exhibits the TC for D018–D043. If the waste exhibits any other characteristic or contains a listed hazardous waste, it would be regulated under both TSCA and RCRA. [RO 13324, 14014]

TC examples

The following examples provide EPA insight into application of the TC.

Lead containers or container liners are sometimes used as shielding when low-level radioactive wastes are landfilled. A representative sample of the container plus contents would likely fail the TCLP. Therefore, would these containers have to be considered mixed waste when land disposed?

No. The lead containers or container liners are not regulated as hazardous waste because they are products fulfilling their intended purpose. Assuming that the container contents do not meet the definition of a hazardous waste, such containers of low-level radioactive waste could be disposed in a radioactive waste landfill without concern for the lead in the container. While the lead shielding is not a solid waste, EPA recommends that the outside be macroencapsulated (e.g., with a polymer coating) to prevent the shielding from leaching lead into the environment. [RO 12956, 13468, 13538]

Conversely, if the radioactive contents are removed from the container prior to disposal, and the empty lead containers or container liners are now to be landfilled, they would be solid wastes (no longer products) being discarded. Solid wastes that exhibit the TC are hazardous when disposed.

If lead-lined pipe or lead-shielded phone cable is abandoned in place, are any hazardous waste requirements triggered?

Yes. Abandonment constitutes disposal of a solid waste. If hazardous for lead (D008), the material would have to meet land disposal restrictions. [RO 13468]

Is used antifreeze removed from radiators a hazardous waste?

Used antifreeze is typically not ignitable, corrosive, or reactive. Ethylene glycol, the primary ingredient in antifreeze, is not one of the 40 TC constituents; therefore, it will normally be hazardous only due to lead or other heavy metal content (picked up from the radiator). According to one reference, up to 40% of antifreeze drained from radiators can exhibit the TC for lead. [RO 11554, 14003] Each generator should conduct TCLP testing on representative samples of its used antifreeze to make a facility-specific determination of whether its used antifreeze is toxic or not. [RO 13521] If it is, it should be managed in a satellite accumulation or 90/180/270-day container prior to hazardous waste disposal or recycling. If the drained coolant does not exhibit any hazardous waste characteristic, however, it may be recycled or disposed in a nonhazardous waste facility.

We sometimes hear of used antifreeze that, upon TCLP testing, contains high levels of arsenic and/or selenium; however, knowledge indicates that neither arsenic nor selenium are present in the materials of construction of the radiator and neither are contained in any process fluids which could leak into the antifreeze. An EPA-funded study found that arsenic and/or selenium may appear as false positives during the analytical process. Although the study was not able to definitively determine the cause of the analytical discrepancy, it did indicate that false positives were not observed when using Methods 6020 or 7060, instead of the more common Method 6010, to test for heavy metals in TCLP leachates from used antifreeze. Note that Method 7060 was deleted from SW–846 in 2007. A complete discussion of these results is contained in Waste Analyses Project for Auto Dealerships—Waste Antifreeze Summary, September 2006, available at

Masking of lead-bearing wastes prior to disposal is prohibited

It was common practice in the 1990s for some industries to add iron fines, filings, or dust to wastes characteristically hazardous for lead. This practice occurred frequently at foundries that would mix iron filings with D008 foundry sand. The iron filings interfered with the TCLP, resulting in treated sand that appeared to meet LDR treatment standards and therefore could be land disposed. Based on EPA’s research into this practice, the agency concluded that the “masking” effect is only temporary:

“[T]he addition of iron metal is not a permanent treatment because the iron inevitably oxidizes and loses its adsorptivity for soluble lead ions. After oxidation of the iron surfaces, surface adsorption of lead ions ceases and the lead-bearing waste returns to its original state; all pretext of treatment is lost. Since iron addition is not effective, it cannot be allowed for lead-containing hazardous wastes that are to be land disposed, regardless of their origin (i.e., all lead-bearing wastes, not just foundry sands). The agency concludes that addition of iron metal, in the form of fines, filings, or dust, fails to provide long-term treatment for lead-containing hazardous wastes. EPA is codifying this determination by calling this practice impermissible dilution, and so invalidating it as a means of treating lead in lead-containing hazardous wastes.” [May 26, 1998; 63 FR 28568]

The dilution prohibition is codified in §268.3(d).

Lead-based paint waste

Some contractors involved in removal of lead-based paint (LBP) use iron-containing additives in the abrasives used to blast off the paint. Other products are applied to the paint, causing it to separate from the equipment or structure for subsequent removal. These practices have the same effect as discussed above—the removed LBP waste (which includes the abrasive or paint remover) typically passes the TCLP because of the masking effect of the iron. When the dilution prohibition was approaching promulgation, these entities asked EPA if the new regulation would prohibit this practice. EPA responded that “the dilution prohibition does not apply to processes which generate a waste, only to processes that treat a waste which already has been generated.” [63 FR 28568]

Based on this position, the contractors’ practice discussed above continues to be acceptable. What is not allowed under §268.3(d) is the addition of iron filings or shot to LBP waste that has already been generated. EPA defines the point of generation for such wastes as “once the paint has been removed from the surface of the structure.” [RO 14069]

Although the use of iron-containing abrasives for removing LBP is not prohibited, EPA noted that, because the iron in the abrasive only temporarily prevents lead from leaching from the waste, two factors may come back to haunt the generators of such waste:

  1. If the LBP waste passes the TCLP initially but then fails later prior to disposal, the waste is hazardous, subject to all applicable Subtitle C regulations.
  2. CERCLA liability is independent of any previous hazardous waste determination. LBP waste that passes the TCLP, is disposed in a Subtitle D landfill, and then subsequently causes environmental damage from leachable lead will subject responsible parties to CERCLA liability. [63 FR 28568, RO 11624, 14069]

Delisting petitions

EPA requires the use of the TCLP for all testing used to support delisting petitions submitted under §§260.20 and 260.22. For all delisting demonstrations, the agency requires that the TCLP be used to predict the leaching potential of any inorganic and organic constituents listed in Appendix VIII to Part 261. As such, TCLP extracts should be analyzed for any inorganic or organic constituents that may be present in the waste. Analysis of total constituent concentrations of metals, cyanides, sulfides, and any organic constituents will also be required.

The leaching step of the TCLP is not performed on liquid wastes (i.e., those with less than 0.5% filterable solids). As a result, the TCLP will not be required for delisting demonstrations pertaining to liquid wastes. Instead, total constituent data will be used to determine if a liquid waste should remain hazardous.

As mentioned earlier, the TCLP is often not appropriate for evaluating oily wastes. Consequently, for wastes that contain more than 1% total oil and grease and that are difficult to filter using the TCLP (e.g., tars), EPA requires the use of the OWEP in place of the TCLP to determine the leaching potential of inorganic constituents. [RO 11522, 12450]


Topic: P- and U-Listed Hazardous Wastes

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