RCRA Empty Containers

On November 25, 1980, EPA decided that “except where the hazardous waste is an acutely hazardous material listed in §261.33(e), the small amount of hazardous waste residue that remains in individual empty, unrinsed containers does not pose a substantial hazard to human health or the environment.” [45 FR 78525] Thus, such residues in “RCRA-empty” containers are not subject to hazardous waste management requirements. In that Federal Register, the agency promulgated rules for what constitutes a RCRA-empty container in §261.7.

EPA issued these regulations to let facilities know how to empty their containers so they would no longer be subject to RCRA regulation, even if some residue remains in them. Therefore, these regs allow owners/operators to reuse containers meeting the provisions in §261.7, since the container is no longer considered to hold hazardous waste. [EPA/530/K-05/010]

It is important to note that the §261.7 regulations exempt only the residue remaining in an empty container; the regs do not apply to the container itself. Consequently, if a RCRA-empty container that is being discarded itself exhibits a characteristic (e.g., it is made out of lead or is an unpunctured aerosol can that exhibits the reactivity characteristic), the container would have to be managed as a hazardous waste, even though the residue would be deemed nonhazardous. [RO 11219, 13027, 13435]

Of course, hazardous waste residue in any container that is not RCRA-empty remains subject to full Subtitle C regulation, unless some exemption applies. If a container holding hazardous waste is not RCRA-empty and is being sent to a drum reconditioner for cleaning and reuse, for example, the container must be manifested and may only be shipped to a facility with a RCRA permit (or interim status) or to a recycling facility. [45 FR 78527, RO 11089]

The empty-container requirements apply to three different types of containers: 1) containers or inner liners that held nonacute hazardous waste, 2) containers or inner liners that held acute hazardous waste, and 3) containers that held compressed gas. The RCRA-empty criteria for each of these three types of containers are examined below.

Containers that held nonacute hazardous waste

Containers or inner liners that have held any nonacute hazardous waste (other than a compressed gas) qualify as RCRA-empty if they meet two requirements: 1) use of a common container emptying practice, and 2) either a residue depth or weight limit. (Nonacute hazardous wastes are all D-, F- (other than dioxin-containing F-wastes having an (H) code in the right-hand column of §261.31), K-, and U-wastes.)

If the depth limit is used, all wastes must have been removed that can be removed using “commonly employed practices” (e.g., pouring, pumping, and aspirating) and no more than one inch of residue may remain on the bottom of the container or inner liner. Alternatively, containers may be deemed empty if all wastes have been removed that can be removed using commonly employed practices and no more than 3% by weight of the total capacity of the container remains in the container or inner liner. This 3% limit is for containers with capacities of less than or equal to 119 gallons. For containers greater than 119 gallons in size, no more than 0.3% by weight of the total capacity of the container may remain in the container or inner liner. [§261.7(b)(1)]

Commonly employed practices

The first requirement that must be met for a container of nonacute hazardous waste to be considered empty is that residues must have been removed using practices commonly employed for emptying that type of container. The regs at §261.7(b)(1)(i) call out pouring, pumping, and aspirating as common practices; EPA/530/K-05/010 adds “draining” to the list. “Commonly employed” refers to the normal practice of industry, not to what a given person does. Thus, containers that have not been subjected to all commonly employed methods of emptying are still subject to regulation. [RO 11048]

EPA has provided scattered guidance on commonly employed practices for different types of containers, including the following:

 

The one-inch requirement

As EPA noted in the preamble to the August 18, 1982 amendments to the empty-container provisions, one inch of waste “may remain in an empty container only if it cannot be removed by normal means…. On the other hand, if extraordinary means are necessary to remove the waste to lower the contents of the container down to a depth of one inch, then they must be employed.” [Emphasis in original.] [47 FR 36093]

Q Two inches of nonacute pesticide residue is rinsed out of a 55-gallon drum, and the rinsewater is disposed. What is the status of the rinsewater?

A Because the drum was not RCRA-empty (i.e., it retained more than one inch of residue), the residue was still subject to regulation. If the rinsewater is a mixture containing a pesticide listed as a U-waste when discarded, the rinsewater is a U-listed hazardous waste via the mixture rule. If the pesticide is not U-listed, the rinsewater is only hazardous if it exhibits a characteristic. [RO 11374]

Q A generator sends a sample of a spent solvent (F004) waste to a laboratory for analysis. During analysis, laboratory equipment, such as a pipet, is used. After the analysis is performed, would the empty pipet (which will be discarded) be considered hazardous waste?

A At the lab, any wastes generated from the analysis would still be considered F004 wastes under the “contained-in” policy. However, some of the laboratory equipment used in the analysis, such as a pipet, may meet the definition of a container and therefore would not be regulated as hazardous waste if it met the §261.7 empty criteria. [RO 13375]

Q If a spent filter cartridge has been drained, is it considered to be an empty container?

A No. EPA does not consider spent filter cartridges to be containers, so the empty-container provisions would not apply to spent cartridges contaminated with hazardous waste. [OSWER Directive 9444.18(84)]

The weight-limit alternatives

In some situations, it may be very hard to measure the depth of residue in the bottom of containers due to their shape (rounded or conical bottoms) or the position of the container opening. Nevertheless, EPA has stipulated that the residue depth must be measured from the deepest point of the bottom of the container. [August 18, 1982; 47 FR 36093] Due to these difficulties, EPA allows the generator to choose a weight limit as an alternative to the one-inch criterion.

Two different weight criteria are specified, depending on the size of the container. Containers with capacities of less than or equal to 119 gallons can contain no more than 3% by weight of their total capacity; no more than 0.3% by weight of the total capacity of the container can remain for containers greater than 119 gallons in size. The 3% limit for containers with capacities of less than or equal to 119 gallons is based on the fact that 3% by weight of the contents of a standard 55-gallon drum (one of the most common containers for hazardous waste) is equal to 1 inch of residue on the bottom of that drum.

Typically, if hazardous wastes are transported in containers larger than 119 gallons in size, they are transported in tank-like containers of at least 5,000-gallon capacities (e.g., portable tanks, cargo tanks, and tank cars). Consequently, EPA based the 0.3% by weight limit on the fact that 0.3% by weight of a 10,000-gallon tank (30 gallons) is roughly equivalent to 1 inch of residue. [August 18, 1982; 47 FR 36093]

Empty aerosol cans are still hazardous

Rendering aerosol cans empty so they will exit RCRA hazardous waste management is problematic. Even an empty aerosol can may still be hazardous waste. This is the federal interpretation; some authorized states have taken a different approach to managing these wastes. For example, Colorado has added aerosol cans as a universal waste. Additionally, some states (e.g., California) define an empty aerosol can to be nonhazardous. Consequently, it is important to contact the appropriate state agency to find out if they have different regulations or policies that apply to these wastes.

Q A furniture manufacturer generates spent aerosol paint and solvent cans from painting and cleaning activities. The cans are emptied using common industry practices and contain less than 3% by weight of the total can capacity. However, they may still be capable of detonation if subjected to a strong initiating source or if heated under confinement. Do the cans meet EPA’s definition of empty and, as such, can they be disposed as nonhazardous waste?

A Even though the aerosol cans are RCRA-empty (i.e., commonly employed emptying practices have been used and they contain less than 3% by weight hazardous wastes), they still may demonstrate the RCRA hazardous characteristic of reactivity per §261.23(a)(6). Accordingly, they may be hazardous wastes, and if they are, they must be managed as such. [RO 13027]

Containers that held acute hazardous waste

Containers or inner liners that held acute hazardous waste listed in §261.31 (the dioxin F-wastes) or 261.33(e) (the P-wastes) are RCRA-empty if:

These requirements are more stringent than those for containers holding nonacute hazardous waste because acute hazardous wastes pose a greater hazard to human health and the environment.

Q Epinephrine (P042 when discarded) is a drug that is injected using syringes. Since some of the drug typically remains in the syringe after injection, should residual drug in such syringes be managed as P042 until triple rinsed?

A No. EPA considers that drug residues remaining in used syringes have been used for their intended purpose and are not discarded commercial chemical products. Therefore, the residues in this example would not be P042 but would be hazardous waste only if they exhibit a characteristic. [RO 13718] Additionally, EPA clarified in RO 14788 that this epinephrine interpretation extends to other P- and U-listed pharmaceuticals administered by syringe. The agency went on to clarify (as it also had in RO 13718), that even though not listed, syringe residues exhibiting a characteristic must be managed in accordance with the hazardous waste regulations.

Triple rinsing

The typical method of rendering empty a container that held an acute hazardous waste is to triple rinse it with a suitable solvent. Water is often used if the chemical is water soluble. Otherwise, another appropriate solvent must be employed.

The rinsate from containers being triple rinsed is a hazardous waste if it 1) exhibits a hazardous waste characteristic, or 2) comes out of a nonempty container. This last provision provides that rinsates one, two, and three (none of which came from an empty container) are listed hazardous waste via the mixture rule. If a container were rinsed a fourth time, the rinsate would come from an empty container and would not be hazardous unless it exhibits a characteristic. [August 18, 1982; 47 FR 36095, RO 11004, 12299]

The regulations don’t specify the volume of solvent that should be used in each of the three rinses. When the RCRA regs were proposed, however, EPA said that “a volume of diluent at least equal to ten percent of the container’s capacity” should be used for each rinse. [December 18, 1978; 43 FR 58955] Based on this proposed language (which was never finalized), an industrial “rule of thumb” is that a rinse volume of about 10% of the container capacity should be used. It turns out that this “rule of thumb” is actually codified in the TSCA regs for decontaminating a PCB container. At 40 CFR 761.79(c)(1), EPA notes that “Each rinse shall use a volume of the flushing solvent equal to approximately 10 percent of the PCB Container capacity.” Conversely, EPA recently issued pesticide container rinsing instructions at 40 CFR 156.146 requiring containers to be filled 1/4 full with solvent prior to shaking or tipping.

Note that triple rinsing is not considered treatment in the federal regs, and, consequently, a permit is not required. [November 25, 1980; 45 FR 78528]

Q A drum recycler burns the hazardous waste residue left in drums that have been triple rinsed (i.e., the drums are RCRA-empty). Does this practice constitute hazardous waste incineration subject to RCRA regulation?

A No. Since the residue is not regulated as a hazardous waste under §261.7(a)(1), burning it would not be considered hazardous waste treatment, and the activity would not be subject to RCRA regulation or require a permit. [RO 12535]

Q Do the triple rinsing requirements apply to containers that hold residues (e.g., ash) from incinerating acute hazardous wastes?

A Yes. The triple rinsing standards apply to these types of containers in order to render them empty under RCRA. However, the agency points out that §261.7(b)(3)(ii) allows the use of alternative cleaning methods in place of triple rinsing. If data are available proving that incineration eliminates the hazardous constituents in the acute hazardous wastes, perhaps such a determination could be made. [RO 11761]

Alternative cleaning methods

No formal EPA approval is required for alternative cleaning methods under §261.7(b)(3)(ii); that is, the alternative is self-implementing. However, EPA suggests that anyone using an alternative method be sure to document the equivalency of the method and its use and keep such records as part of the facility’s operating log. Discussing use of the method with the appropriate agency responsible for administering hazardous waste regulations might also be helpful. [RO 11761, 11803]

Q How should a generator empty paper bags that contain acute hazardous waste that is physically solid?

A EPA has determined that repeated beating of the outside of the inverted paper bags after emptying them can be an alternative to triple rinsing. [RO 12407]

Containers that held compressed gas

As set forth in §261.7(b)(2), a container that held a hazardous compressed gas is empty when the pressure in the container approaches atmospheric pressure. Products on the P- and U-lists (i.e., commercial chemical products that are hazardous wastes when discarded) that are gases at standard temperature include P031—cyanogen, P033—cyanogen chloride, P063—hydrogen cyanide, P096—phosphine, U001—acetaldehyde, U043—vinyl chloride, U045—chloromethane, U122—formaldehyde, and U135—hydrogen sulfide. Even if the gaseous material in the container is an acute P-waste, the container is empty when the pressure approaches atmospheric pressure. [RO 12138]

Q Discarded vinyl chloride gas (U043) is transported to a TSD facility in a rail car. When it arrives at the TSD facility, the gas is removed from the rail car, and the rail car is opened to the atmosphere, rendering it empty in accordance with §261.7(b)(2). The empty rail car is then sealed and shipped back to the generator. During shipment, the empty rail car is heated by the sun, and the remaining gaseous residue inside the rail car subsequently develops pressure. Is the pressurized residue subject to regulation as hazardous waste?

A No. “It is not EPA’s intent to regulate containers in such situations where an incidental rise in pressure occurs resulting from ambient environmental conditions. In this specific rail-car scenario, the ‘empty’ status of the rail car does not change due to the heating from the sun.” [RO 14120]

Cylinders returned to gas suppliers and removal of residues

Due to unique ownership issues surrounding compressed gas containers or cylinders, EPA has provided guidance on who is responsible for managing compressed gas remaining in cylinders. Compressed gas cylinders, which are typically owned by the gas supplier, are usually returned to the supplier when they are empty or when the customer no longer needs them. The purpose of this shipment is for refilling and/or to return the supplier’s property, not to discard the remaining contents of the cylinder. Therefore, the customer does not have any input on the final disposition of the residue in the cylinder, which occurs at the supplier’s facility at the supplier’s discretion.

Consequently, EPA has determined that returning a compressed gas cylinder to the supplier does not constitute generation of waste under RCRA. Neither the returned cylinder nor the residue it contains is a “solid waste,” even if the cylinder is not empty (i.e., it is still pressurized). As such, the shipment of cylinders from the customer back to the supplier does not have to be manifested. However, Department of Transportation (DOT) requirements will apply, and the cylinders may have to be transported as DOT hazardous materials. [August 18, 1982; 47 FR 36094, RO 14759, 14760, 14762]

If the gas supplier decides to discard the contents of returned cylinders, any liquid or physically solid waste removed from the cylinders is regulated if it is hazardous waste. If the supplier sends the cylinders offsite for treatment, storage, or disposal, they must be manifested if they are not empty and contain hazardous waste.

Although the above quotation from EPA guidance might lead a facility to believe it is acceptable to vent unwanted gas from compressed gas cylinders, we have significant reservations about that practice. First, RO 11835 suggests that, if all of the materials generated by the venting (including the cylinders) will be discarded, then the practice might be considered treatment requiring a RCRA permit. Second, such venting may violate state air regulations or the conditions in a facility’s air permit. These concerns argue against this practice and we strongly recommend not venting gases from compressed gas cylinders to the atmosphere.

Beneficial reuse of residues

Sometimes, residues in containers are not intended for disposal but rather for reuse. For example, if a container that has held a P- or U-listed commercial chemical product is to be reused to contain the same material that it previously held (and the initial residue is not discarded), that constitutes a beneficial use or reuse of that residue. In such situations, EPA notes that the residues never became wastes, and the accumulation, transportation, and treatment prior to use or reuse is exempt from hazardous waste management. Another situation is when a material is mixed into a container holding a P- or U-listed product residue, where the mixing constitutes a beneficial use or reuse of that residue. [§261.33(c), November 25, 1980; 45 FR 78527] An example of this situation might be where a drum contains a U-listed solvent residue, and unused paint is mixed with the residue in the drum in order to make it “sprayable.”

Regulatory status of residues removed from empty containers

Under §261.7(a)(1), any hazardous waste remaining in either an empty container or an inner liner removed from an empty container is not regulated as hazardous waste (i.e., the RCRA hazardous waste regulations, including the land disposal restrictions, do not apply). [RO 12793] Since residues remaining in RCRA-empty containers are not regulated, it would seem reasonable that any management practices associated with residues removed from empty containers would not constitute hazardous waste management or treatment.

This was EPA’s original (1980) position regarding residues or rinses removed from empty containers. However, even then, the agency was concerned that drum reconditioners and other facilities that clean out large numbers of RCRA-empty containers might accumulate, treat, and/or dispose significant quantities of these unregulated residues, which could pose a hazard to human health and the environment. Therefore, in the November 25, 1980 Federal Register, EPA sought input on a number of approaches for regulating residues removed from RCRA-empty containers. [45 FR 78526] After reviewing comments submitted, the agency decided not to amend the §261.7 provisions and not to regulate such removed residues. [August 18, 1982; 47 FR 36096]

Throughout the 1980s and early 1990s, EPA reiterated in guidance that, when residues are removed from RCRA-empty containers, the resulting residues, rinsates, or washwaters are also exempt from RCRA under §261.7(a)(1). Accordingly, generators would not have had to determine whether they exhibit a hazardous waste characteristic. However, residues, rinsates, or washwaters that result from cleaning out containers that do not meet the §261.7 definition of empty (or result from activities that render the container RCRA-empty) are not exempt but are fully subject to RCRA Subtitle C if they either exhibit a characteristic or are a mixture containing a listed hazardous waste. [RO 11447, 11504]

In 2004, however, EPA reverted back to its earlier concerns about residues removed from RCRA-empty containers. In RO 14708, the agency noted that “when residue is removed from an ‘empty’ container, the residue is subject to full regulation under Subtitle C if the removal or subsequent management of the residue generates a new hazardous waste that exhibits any of the characteristics identified in Part 261, Subpart C....” (See also October 4, 2005; 70 FR 57779.)

This April 2004 letter makes EPA headquarters consistent with the conservative positions previously taken by some of the regions and states. For example, EPA Region I has for some time required characterization of residues/rinsates from RCRA-empty containers, as discussed in Case Study 2.

 

RO 14708 adds that “if the rinsing agent includes a solvent (or other chemical) that would be a listed hazardous waste when discarded, then the rinsate from an ‘empty’ container would be considered a listed hazardous waste.” This would be due to the nature of the rinsing agent (e.g., toluene used to clean out a RCRA-empty drum would be F005 listed spent solvent), not due to the residues remaining in the empty container. (See also October 4, 2005; 70 FR 57779.)

Discharging rinsates into wastewater treatment systems

EPA believes that small amounts of chemicals that, when discarded, are hazardous wastes listed in §261.33 and small amounts of F- and K-wastes are often “unavoidably lost” during normal material handling operations; such activities include emptying and rinsing containers. Facilities frequently dispose such chemicals and F- and K-wastes rinsed out of containers by draining or washing them into the facilities’ wastewater treatment systems. According to the agency, “[t]his typically is a reasonable and practical means of disposing of these lost materials. Segregating and separately managing them often would be exceedingly expensive and may not be necessary because the small quantities can be assimilated and treated in the wastewater treatment system.” [November 17, 1981; 46 FR 56586] Due to the small quantities of wastes involved, the agency does not believe that this practice poses a substantial threat to human health or the environment.

Based on this reasoning, EPA exempts mixtures of wastewater and such de minimis losses of P- and U-listed chemical rinsates and F- and K-waste container rinsates from RCRA regulation under §261.3(a)(2)(iv)(D) if they are discharged to wastewater treatment systems regulated under the Clean Water Act. Included in this exemption is rinsate from empty containers or from containers that are rendered empty by that rinsing. This exemption lets facilities discharge rinses from containers holding §261.31 F-wastes, §261.32 K-wastes, and §261.33 chemicals into their wastewater treatment system without worrying about hazardous waste management. The wording of the exemption indicates that, as long as the rinsate flows into the wastewater treatment system, it doesn’t matter if the container was RCRA-empty or not before it was rinsed (although the container must be RCRA-empty after rinsing).

Note that EPA provided some disconcerting guidance about these de minimis losses from container rinsing. On January 31, 1991, the agency noted that only the “third rinse in triple rinsing” would meet the definition of rinsate from containers that are rendered empty by that rinsing. [56 FR 3869]

Miscellaneous empty-container examples

Three additional examples illustrating the complex considerations of managing and emptying a hazardous waste container are given in Case Study 3.

 

RCRA and DOT definitions of “empty” are different

Even though an empty container may be exempt from RCRA requirements, DOT shipping requirements may still apply because the RCRA and DOT definitions of an “empty” container are not the same. Under the 49 CFR 173.29 DOT standards, any packaging (e.g., container) that contains residues of hazardous materials must be handled and transported as if it were full unless it meets all of the following criteria:

Manifesting nonempty shipments back to a generator

Due to the sticky nature or other properties of some hazardous waste, it is often very difficult, if not impossible, for a TSD facility to render a generator’s tank truck or rail car RCRA-empty. Therefore, when the TSD facility sends the container back to the generator to pick up more of the same waste (i.e., the container is dedicated to this service), the shipment consists of a nonempty container of hazardous waste that should be manifested.

In a March 4, 2005 final rule that changed the manifest system starting September 5, 2006 [70 FR 10776], EPA modified the definition of “designated facility” in §260.10 to include generators receiving non-RCRA-empty containers returned under a new manifest from a TSD facility. Generators receiving such returned shipments must sign in Block 20 of the new manifest, and they then have either 90 or 180 days (depending on their generator status) to send returned waste to another designated facility under yet another manifest. [§262.34(m)]

Waste counting issues

Per §261.5(c)(1), residues in RCRA-empty containers are not counted when making monthly generator status determinations.

CERCLA issues

Material contained in RCRA-empty containers that is sent offsite for disposal must be reported as an offsite transfer for purposes of disposal on Form R of the toxic release inventory (TRI). This situation occurs because material remaining in empty containers is still considered a toxic chemical under the Emergency Planning and Community Right-to-Know Act (EPCRA) Section 313. The status of a toxic chemical as nonhazardous waste under RCRA has no impact on the applicability of EPCRA regulations. Therefore, the quantity of such material should be reported in Section 8.1 of Form R, unless the facility is exempt from reporting. [EPCRA Hotline question and answer dated February 1996]