               Modernizing Ignitable Liquids Determinations Rule
                             Response to Comments
                       Docket ID: EPA-HQ-OLEM-2018-0830

                                 Introduction

On April 2, 2019 EPA proposed to update the regulations for ignitable hazardous waste under title 40 of the Code of Federal Regulations (CFR), part 261, with comments on the rule accepted until June 3, 2019 (see 84 FR 12539, April 2, 2019).

This document contains the comments on the rule and EPA responses, grouped by subject area. The comment excerpts were taken verbatim from the comments submitted to EPA. The comment ID number corresponds to the public commenters described in the Commenter Key at the end of this document. EPA's response to each comment is found immediately following the comment. In some cases, similar comments have been grouped together and have one response at the end of the grouping.

All comments and supporting documents for the rule (including this document) can be found at https://www.regulations.gov/docket?D=EPA-HQ-OLEM-2018-0830.

Table of Contents

1.	Proposed Flash Point Test Methods	4
2.	Continued Use of Existing Flash Point Test Method Requirements and the Potential for Conflicting Results	7
3.	Replacement of Mercury Thermometers	11
4.	Update to Outdated Regulations that Reference DOT Regulations	13
5.	Aqueous Alcohol Exclusion General Comments	14
6.	Definition of Aqueous as 50% Water by Weight	16
7.	Concern that EPA is Narrowing the Aqueous Alcohol Exclusion	17
8.	Additional Comments on the Aqueous Alcohols Exclusion	26
9.	Identification of Multiple Phase Wastes	29
10.	Pressure Filtration and Ignitable Liquids	38
11.	Economic or Regulatory Impacts	43
12.	Miscellaneous/Other	48

       Comments on the Modernizing Ignitable Liquids Determinations Rule
Proposed Flash Point Test Methods
Comment Excerpt:
EPA is proposing to replace the two analytical methods for ignitability (the Pensky-Martens method 1010A, and Setaflash method 1020B) with updated versions that reference the updated 2018 ASTM methods D8175-18 and D8174.18 respectively that use automatic electronic flash point detection. These will be referenced in 261.21(a)(1). The old methods will stay in the regulations as additional options for ignitability testing. AFPM supports these changes.
      The Methods Innovation Rule - EPA will incorporate by reference several method updates that are in SW-846 or are ASTM methods currently in use latest versions. AFPM supports this.  [Commenter 1]
Response: Thank you for your comment supporting EPA's proposal to add modern flash point methods while retaining existing methods in the regulations for the identification of ignitable hazardous waste. These changes are being finalized as proposed.

Comment Excerpt:
ACIL totally supports the proposed changes to the hazardous waste regulations that will modernize how the hazardous waste characteristic of ignitability is determined under the Resource Conservation and Recovery Act. We support the changes for [the following reason]. The current tests Pensky-Martens and Setaflash flash point determination methods referenced in 40 CFR Part 260.21 and required to be employed by laboratories when characterizing wastes are more than 30 years old. These tests were developed by the American Society for Testing and Materials (ASTM), a well-recognized, national consensus standards method development organization. Since that time, ASTM committees have updated the methods several times to reflect scientific and technological advances in flash point determination. As a result, the cited versions of the Pensky-Martens and Setaflash methods have become outdated, and their use presents several challenges to our members and to the regulated community which we serve. [Commenter 5]
Response: Thank you for your comment supporting EPA's proposal to add modern flash point methods to the regulations for the identification of ignitable hazardous waste. These changes are being finalized as proposed.

Comment Excerpt:
The Addition of New Flash Point Tests Methods is Appropriate: API supports the EPA's proposal to add ASTM standards D8174-18 and D8175-18 to the regulation as approved test methods for determination of ignitability characteristic of hazardous wastes. The D8175-18 standard is a modified D93-16 method, specifically developed for the flash point testing of waste matrixes. Similarly, the D8174-18 standard is modified from the existing D3828-16 standard and is more appropriate for waste testing.  [Commenter 6]
Response: Thank you for your comment supporting EPA's proposal to add modern flash point methods to the regulations for the identification of ignitable hazardous waste. These changes are being finalized as proposed, and the existing flash point methods are also being retained.

Comment Excerpt:
EPA's Proposed Revisions to Flash Point Test Methods: CPAI supports EPA's proposal to update its test methods to incorporate the more modern ASTM standards D8175-18 and D 8174-18 for flash point testing. CPAI agrees that the test methods currently specified in 40 CFR 261.21(a)(l) should be retained to allow the continued use of older testing equipment.  [Commenter 8]
Response: Thank you for your comment supporting EPA's proposal to retain the existing flash point tests incorporated by reference. EPA is retaining the existing flash point methods while also finalizing the proposed, modern methods in the final rule.

Comment Excerpt:
Updating flash point test methods:  EPA is proposing to update Method 1010A to 1010B. This will add ASTM D 93-18 to the list of flash point methods. In addition, EPA is proposing to update Method 1020B to Method 1020C. This will add ASTM D 8174-18. CRWI supports both of these changes. We believe that these updates will bring the methods more in line with current flash point testing devices.  [Commenter 9]
Response: Thank you for your comment supporting EPA's proposal to add modern flash point methods, ASTM standards D8175-18 and D8174-18, to the regulations for the identification of ignitable hazardous waste. These changes are being finalized as proposed, and the existing flash point methods are also being retained.

Comment Excerpt:
As we already know, Ignitable hazardous waste is very risky as it can catch fire very easily. They can be liquids, solids or compressed gasses. Pensky-Martens Flash point tester is one of the most accurate/precise tests for identifying the flash points (ignition points) of any substance. All waste contaminate the environment but some waste is dangerous than others. Hazardous ignitable waste can cause harm to the environment. If an ignitable waste is not accurately discovered, it may be characterized as another form of hazardous waste and disposed of differently. Even though all hazardous waste is disposed of safely, disposing of waste in the wrong way may cause accidents (Fire in this case). This would ultimately cause air and land pollution, and possible health issues to the people living nearby. With using a test that is more accurate, many such accidents would be avoided. Thus, I think it is a good idea to modernize the test instead of using traditional mercury testers.  [Commenter 3]
Response: Thank you for your comment supporting EPA's proposal to add modern flash point methods to the regulations for the identification of ignitable hazardous waste. These changes are being finalized as proposed, and the existing flash point methods are also being retained.

Continued Use of Existing Flash Point Test Method Requirements and the Potential for Conflicting Results
Comment Excerpt:
       The Retail Associations Generally Support Some of the Technical Changes EPA Has Proposed for the Ignitability Test Methods, But Has Some Related Concerns:  EPA has proposed a number of technical changes to the test methods used to evaluate the ignitability of wastes. Some of the changes are designed to allow the use of more modern methods to test the flash point of liquids (e.g., methods that use non-mercury temperature measuring devices and electric spark ignition, rather than flame ignition). Others are designed to harmonize the definitions of ignitable compressed gases and oxidizers with the corresponding definitions under the Hazardous Materials Regulations issued by DOT.
       The Retail Associations generally support these changes. However, we are concerned about one aspect of the proposal for the flash point test methods. Under the proposed rule, a liquid waste would generally be classified as ignitable if it has a low flash point "as determined by using one of [several] standards." See 84 Fed. Reg. at 12,552 (proposed to be codified at 40 C.F.R. § 261.21(a)(1)). This language leaves open the question of the status of a waste if different ones of the specified tests (properly performed) yield different results.
       We urge EPA to clarify that if a generator properly determines using one test method that a waste has a flash point outside the ignitable range (i.e., above 60°C or 140°F), it can rely on that result and manage the waste as non-ignitable. If a generator does not have that assurance, and has to be concerned that a regulator might reach a different conclusion based on one of the other specified test methods, it might effectively be forced to run all of the specified test methods (especially in cases where the flash point initially measured is close to the regulatory threshold). The rule in this way would effectively be transformed to define all liquid wastes as ignitable unless the flash points measured by all of the specified tests are above the regulatory threshold. This would be a major change to the regulation, and would lead to unnecessary and duplicative testing, at great expense and for no environmental benefit. We doubt that this is what EPA intended, so we urge the Agency to clarify that one test is sufficient.  [Commenter 2]
Response: Thank you for your comment. As explained in the preamble of the final rule, a generator is required by 40 CFR 262.11 to make an accurate determination with testing and/or knowledge. A generator does not need to conduct multiple tests or all tests to ensure they have made an accurate determination. See section III.A.3 of the final rule preamble for further discussion.

Comment Excerpt:
       Flash point test methods: ACC supports EPA's proposal to modernize the approved flash point test methods. EPA has proposed to add ASTM standards D8174-18 and D8175-18 to the regulation as approved test methods for determination of ignitability characteristic of hazardous wastes. The D8175-18 standard is a modified D93-16 method, specifically developed for the flash point testing of waste matrixes. Similarly, the D8174-18 standard is modified from the existing D3828-16 standard and is more appropriate for waste testing. ACC appreciates the added flexibility in retaining the currently required flash point test methods  -  ASTM D93-79, D93-80 and D3278-78  -  in the regulation. However, the Agency should consider that flash point is a method defined parameter and the procedural differences between the current methods and the new proposed methods could lead to flash point results that may not be consistent between the different test methods.  [Commenter 4]
Response: Thank you for your comment. As explained in the preamble of the final rule, a generator is required by 40 CFR 262.11 to make an accurate determination with testing and/or knowledge. A generator does not need to conduct multiple tests to ensure they have made an accurate determination. See section III.A.3 of the final rule preamble for further discussion.

Comment Excerpt:
The Retention of Current Flash Point Tests Requires Additional Clarification: API understands the rationale of EPA's proposal to retain the currently required flash point test methods  -  ASTM D93-79, D93-80, and D3278-78  -  in the regulation. However, it must be pointed out that flash point is a method-defined parameter and the procedural differences between the current methods and the new proposed methods could lead to flash point results that may not be consistent across the different test methods. Since the choice of multiple test methods are available to a generator, EPA should make it clear that a waste will not be considered ignitable if it is above the flash point result for the chosen test method.  [Commenter 6]
Response: Thank you for your comment. As explained in the preamble, a generator is required under 40 CFR 262.11 to make an accurate determination with testing and/or knowledge. A generator does not need to conduct multiple tests to ensure they have made an accurate determination. See section III.A.3 of the final rule preamble for further discussion.

Comment Excerpt:
Flashpoint Test Methods:  Stericycle supports the proposal to update the flash point test methods to use new technology and best practices developed by ASTM. 84 FR 12543 col. 3. We understand that EPA is proposing these newer test methods "as an alternative" to current methods, and not as a mandatory replacement. 84 FR 12544 col. 2. We agree with EPA that current test methods still "provide accurate determinations" of whether a liquid waste is characteristic for ignitibility, id., and therefore the newer test methods should be optional, not prescriptive. The final rule should make clear that the current flash point test methods in 40 CFR § 261.21(a)(1) may continue to be used so that all test methods are available.  [Commenter 10]
Response: Thank you for your comment. The Agency is allowing generators to continue using the previously existing flash point test methods in 40 CFR 261.21(a)(1) or the modern flash point methods, ASTM standards D8175-18 and D8174-18, which the Agency is finalizing as proposed, for the determination of characteristically ignitable hazardous waste. See section III.A.3 of the final rule preamble for further discussion.

Comment Excerpt:
Flash Point Test Methods: The ETC supports the proposal to update the flash point test methods to use new technology and best practices developed by ASTM. 84 FR 12543 col. 3. We understand that EPA is proposing these newer test methods "as an alternative" to current methods, and not as a mandatory replacement. 84 FR 12544 col. 2. We agree with EPA that current test methods still "provide accurate determinations" of whether a liquid waste is characteristic for ignitability, id., and therefore the newer test methods should be optional, not prescriptive. The cost of replacing all current equipment to conduct only the new test method(s) would be expensive and unnecessary. We anticipate and agree with EPA that TSD facilities will replace existing test equipment and install the new equipment as needed and based upon a typical upgrade cycle. Therefore, the final rule should make clear that the current flash point test methods in 40 CFR § 261.21(a)(1) may continue to be used so that all test methods are available.  [Commenter 14]
Response: Thank you for your comment. The Agency is finalizing the addition of the new flash point methods as proposed and retaining the current flash point test methods in 40 CFR 261.21. Therefore, the regulated community can continue to use the existing test methods or begin using the new flash point ASTM standards referenced in Methods 1010B and 1020C.

Comment Excerpt:
We have concerns, however, about the manner in which the Agency may choose to update the flash point test methods, which are directly used to determine whether a liquid waste exhibits the ignitability characteristic. In the current proposal, the Agency proposes to retain the current test methods for determining the flash points which have been codified in RCRA regulations for nearly 40 years. EPA requests comment on whether it should remove these methods in the final rule and suggests that it may remove these historic methods in a future regulatory update. 84 Fed. Reg. at 12546.
       We strongly suggest that EPA allow for the ongoing use of the historic flash point test methods until the regulated public can verify the accuracy of the updated methods and gradually transition to using them. While the test methods are intended to yield very similar flash point determinations, the regulated public has not had sufficient opportunity to assess whether this claim is accurate and accordingly cannot provide comments or feedback to support or refute this claim.
       In addition to the accuracy of the updated method, we have concerns that removing these long-standing test methods and requiring liquid wastes to be tested using the updated standards could not only produce different results, but also impose costs on generators and laboratories that have not been sufficiently assessed by EPA's regulatory impact analysis. If the updated test methods do accurately replicate the historic methods and do not impose unreasonable costs on generators and laboratories, the regulated public will certainly transition to their use. Forcing an earlier transition could impose costs that are disproportionate to the benefits of using updated methods and provide no opportunity for the public to verify their accuracy.  [Commenter 15]
Response to Comments:
Thank you for your comments. The Agency is continuing to allow use of the current test methods required prior to this final rule. The Agency is also finalizing the addition of the new flash point test methods as proposed. The Agency expects the newly promulgated test methods in this final rule to have equivalent performance to the current test methods. See section III.A.3 of the final rule preamble for further discussion.

Replacement of Mercury Thermometers
Comment Excerpts:
EPA is proposing to revise some SW846 air sampling and stack emissions methods to remove the requirement to use mercury thermometers and provide alternatives (similar to what EPA did for 40 CFR 60, Method 5 for particulate matter emissions from stationary sources). This would affect methods 0010, 0011, 0020, 0023A and 0051. AFPM supports this change since many labs are already using method 5.  [Commenter 1]
       ACIL totally supports the proposed changes to the hazardous waste regulations that will modernize how the hazardous waste characteristic of ignitability is determined under the Resource Conservation and Recovery Act. We support the changes for [the following reason]. Use of mercury thermometers poses a hazard to our employees. If a mercury containing thermometer breaks during use, it often causes a spill of mercury in the laboratory. This exposes our employees to mercury and cleaning up mercury spills can be difficult, require special equipment, and be costly in time. During the clean-up process employees are exposed to toxic mercury vapor. In addition, disposal of the clean-up residue is expensive as it is a hazardous waste requiring special handling.  [Commenter 5]
Alternatives to mercury thermometers:  EPA has identified five SW-846 methods that require mercury thermometers. These are Methods 0010, 0011, 0020, 0023A, and 0051. EPA is proposing to allow the use of alternative mercury-free thermometers similar to what is allowed under the various forms of Method 5. CRWI supports this proposed modification. Stack testers routinely substitute mercury-free methods when using Method 5 and other methods. This substitution has not created any QA/QC issues and should be encouraged.  [Commenter 9]
The same caveat applies to the phase-out of mercury thermometers. We support EPA's proposal to remove the requirement to use mercury thermometers in the analytical methods, provided the use of non-mercury-containing temperature measuring devices is an option and not a mandatory requirement. While the use of mercury thermometers is steadily decreasing, there is still a substantial supply such that replacement costs would be very high. EPA should allow TSD facilities to purchase and use non-mercury-containing measuring devices for ignitability testing in the normal course of equipment replacement.  [Commenter 14]
Response to Comments:
Thank you for your comments supporting the replacement and phase out of mercury thermometer requirements in the flash point test methods for the determination of characteristically ignitable hazardous waste and the air sampling and stack emissions test methods (Methods 0010, 0011, 0020, 0023A, and 0051). The Agency is finalizing these changes as proposed. EPA is retaining the current test methods but also allowing use of the proposed modernized procedures to provide entities with increased flexibility. See sections III.A. and III.B of the final rule for more details.

Update to Outdated Regulations that Reference DOT Regulations
Comment Excerpts:
EPA is proposing changes to the definition of ignitable gas, to remove references to the Bureau of Explosives, and to align the definition and testing with Department of Transportation's regulations. AFPM supports this change. [Commenter 1]
EPA's Proposed Revisions to D00l definitions based on DOT Hazardous Materials Classifications: CPAI supports EPA's proposals to update those D00l definitions that are based on DOT classifications. Definitions and supporting notes in 40 CFR 261.21 should be updated to include DOT's current descriptions for ignitable compressed gasses and oxidizers. [Commenter 8]
Cross-references to DOT regulations:  EPA is proposing to remove outdated and inaccurate references and notes and replace them with current ones. CRWI agrees that the specific references and notes in the proposed rule regarding Department of Transportation regulations in 40 CFR 261.21 are obsolete and need modification. We support the proposed modifications.  [Commenter 9]
Response to Comments:
Thank you for your comments supporting the update to outdated references to DOT regulations. See section III.C of the final rule for more discussion of the finalization of these changes as proposed.

Aqueous Alcohol Exclusion General Comments
Comment Excerpt:
The Retail Associations Oppose Most of the Proposed Changes to the Exclusion for Aqueous Alcohol Wastes:  Under the ignitability characteristic that has been in place since the beginning of the RCRA regulatory program in 1980, liquid wastes have generally been classified and regulated as ignitable hazardous wastes if they have a flash point less than 60°C (140°F). See 40 C.F.R. § 261.21(a)(1). However, there has always been an exception to this general rule for "aqueous solution[s] containing less than 24 percent alcohol by volume." Id. EPA established this exclusion on the ground that even though such solutions may have a low flash point, they generally do not pose a significant ignitability risk because they are not capable of sustaining combustion. See, e.g., 45 Fed. Reg. 33,084, 33,108 (May 19, 1980) ("This exclusion will remove from the ignitability characteristic liquid wastes which the Agency knows may flash but not sustain combustion").
       In the current proposal, EPA has proposed two main changes to the exclusion for aqueous alcohol wastes. First, the Agency has proposed to modify the exclusion so that it applies to wastes with "at least 50 percent water by weight," rather than "aqueous" wastes. See 84 Fed. Reg. at 12,552 (to be codified at 40 C.F.R. § 261.21(a)(1)). Second, it has proposed to establish an exception from the exclusion "if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005 in 40 CFR 261.31." Id. The Agency has also requested comment on a number of other potential changes to the aqueous alcohol exclusion, such as limiting it to particular wastes or particular alcohols, establishing a minimum alcohol content to qualify for the exclusion, or increasing the required water content above 50%. See 84 Fed. Reg. at 12,547. Each of the changes that EPA has proposed or requested comment on is discussed below. [ Commenter 2]
Response to Comment:
Thank you for your comments. The Agency is finalizing the revision to define aqueous as "at least 50 percent water by weight" but is not finalizing any other changes to the aqueous alcohol exclusion, including the other proposed changes to the exclusion. See sections 6, 7, and 8 below and section III.D in the final rule.

Comment Excerpt:
The proposed rewording of 261.21(a)(1) on p 12552 (col 1) does not take into account that a liquid containing 0% alcohol would meet the "containing less than 24 percent of any alcohol" condition. Thus, as currently proposed, a low-flash liquid containing no alcohol at all and is at least 50% water would be out (!)  [Commenter 12]
Response to Comment:
Thank you for the comment. Aqueous solutions that contain no alcohol do not meet the definition of an aqueous alcohol. The Agency has previously explained in guidance that "If an aqueous waste contains no alcohol, it is not excluded from the definition of ignitable as is wine or latex paint." (RO 12274, see docket ID EPA-HQ-OLEM-2018-0830-0036)
Definition of Aqueous as 50% Water by Weight
Comment Excerpts:
Proposed 50% Water Requirement: As noted above, EPA's first proposal with respect to the aqueous alcohol exclusion is to modify the exclusion so that it applies to wastes with "at least 50 percent water by weight," rather than "aqueous" wastes. See 84 Fed. Reg. at 12,552 (to be codified at 40 C.F.R. § 261.21(a)(1)). The Retail Associations do not object to this change, because they believe that most regulators and members of the regulated community have long interpreted the term "aqueous" waste in this context to mean wastes with greater than 50% water. [Commenter 2]
EPA's Proposed Revision to the Aqueous Alcohol Exclusion: ...Specifically, EPA is proposing to revise the aqueous alcohol exclusion from "other than an aqueous solution containing less than 24 percent alcohol by volume" to "other than a solution containing less than 24 percent of any alcohol or combination of alcohols (except if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005) by volume and at least 50 percent water by weight." This proposed change removes the term "aqueous" from §261.21(a)(l), which is currently undefined in the RCRA hazardous waste regulations and specifies what percentage of water defines the scope of this exclusion. CPAI supports this approach but would not support any additional revisions to the aqueous alcohol exclusion in §261.21(a)(l) without the ability to comment on its revised proposal(s). [Commenter 8]
Aqueous Alcohol Exclusion:  ...Specifically, Stericycle supports EPA's proposal to remove the undefined term "aqueous" from the exclusion and specify that the waste must contain "at least 50 percent water by weight." 58 FR 12546 col. 3. [Commenter 10]
       Aqueous Alcohol Exclusion: ...Specifically, we support EPA's proposal to remove the undefined term "aqueous" from the exclusion and specify that the waste must contain "at least 50 percent water by weight." 58 FR 12546 col. 3. However, in the final rule EPA should be clear that this revision only affects the ignitability regulation and not other RCRA regulations or guidance that refer to aqueous wastes. EPA should proactively avoid creating confusion with respect to other regulations that may rely on a different description or test for aqueous wastes.  [Commenter 14]
Response to Comments:
Thank you for your comments. EPA is finalizing the proposed revision to define aqueous as "at least fifty percent water by weight." See section III.D in the final rule for further discussion.

Concern that EPA is Narrowing the Aqueous Alcohol Exclusion
Comment Excerpts:
EPA is requesting comments on a proposal to revise the 261.21(a)(1) exclusion for "aqueous solutions with less than 24% alcohol" from the definition of ignitability. The proposed exclusion revision is "other than a solution containing less than 24 percent of any alcohol or combination of alcohols (except if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005) by volume and at least 50 percent water by weight." AFPM urges EPA to reconsider this change as it has the potential to broaden the scope of wastes that could be considered ignitable. EPA has not demonstrated a clear justification for this revision by either identifying the types of wastes that now require more stringent management, nor the amounts of wastes that would be captured as a result of this proposal. Lacking a clear analysis of the need to regulate wastes as hazardous that previously were not will burden operators with additional expensive testing and disposal obligations with no additional environmental protection. We recommend that, lacking further supporting documentation, EPA not finalize this proposed revision to the aqueous solutions exclusion.  [Commenter 1]
Proposed Exception for Certain Alcohol Solvent Wastes: EPA's second proposal with respect to the aqueous alcohol exclusion is to establish an exception from the exclusion "if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005 in 40 CFR 261.31." See 84 Fed. Reg. at 12,552 (to be codified at 40 C.F.R. § 261.21(a)(1)). The Retail Associations oppose this proposal on several grounds, as discussed below: [Commenter 2]
-- Would commercial products formulated with one of the four alcohols in order to solubilize other ingredients (e.g., inks, paints, dyes, stains, coatings, lacquers, enamels, varnishes, fragrances) no longer be eligible for the aqueous alcohol exclusion?
      Long-standing EPA guidance makes clear that these commercial products are not covered by the F003 or F005 listings. See, e.g., 50 Fed. Reg. 53,315, 53,316 (December 31, 1985) ("process wastes where solvents were used as ... ingredients in the formulation of commercial chemical products are not covered by the [F001-F005 spent solvent] listing[s]. The products themselves also are not covered"); Letter from Matthew Straus, Chief, Waste Identification Branch, EPA, to Gregory J. Harvey, Newark Air Force Station (May 2, 1986) (RCRA Online #11151) ("the F001 through F005 listings ... do not apply when the solvents are used as ... ingredients in commercial chemical products (e.g., paint and coatings)"). In addition, if the products contain less than 24% alcohol and greater than 50% water, they would currently be eligible for the aqueous alcohol exclusion from the ignitability characteristic. However, under EPA's proposal, they might lose their exclusion and have to be classified as ignitable hazardous wastes, since the alcohol is being used to solubilize other constituents (arguably a "use for its solvent properties") and the guidance on the limits of the F003 and F005 listings are not clearly incorporated into the proposed exception to the aqueous alcohol exclusion.
      We question whether EPA actually intended that the proposed exception would apply in this type of situation, given that the Agency indicated that its proposal was based on a 1990 preamble stating that "[i]f the alcohol has been used for solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005, the waste must be coded with these Hazardous Waste Numbers." See 84 Fed. Reg. at 12,546 and 12,543 (emphasis added), quoting 55 Fed. Reg. 22,520, 22,543 (June 1, 1990). Clearly, the 1990 preamble was focused on wastes that would qualify as F003 or F005 (since otherwise it would make no sense to require use of those codes), so presumably the proposed exception likewise was intended to cover only F003 and F005 wastes (and not other wastes with alcohol solvents, such as these commercial products). However, because of the way that the proposal was worded, considerable uncertainty remains. [Commenter 2]
-- Would unused cleaning/solvent products containing one of the four alcohols no longer be eligible for the aqueous alcohol exclusion?
      These unused cleaning/solvent products would clearly not be F003 or F005 wastes, because those listings apply only to "spent solvents," and unused products would obviously not be spent. In addition, if the products contain less than 24% alcohol and greater than 50% water (with or without other cleaning ingredients such as detergents), they would currently be eligible for the aqueous alcohol exclusion. However, under EPA's proposal, they might lose their exclusion, since the alcohol arguably was used for its solvent properties, by being incorporated as an active ingredient in a cleaning product intended to solubilize dirt or other contaminants.
      We question whether EPA intended that the proposed exception would apply in this type of situation, given that the unused cleaning/solvent product, by definition, has not yet been used. Moreover, as noted above, the proposed exception was apparently based on 1990 language addressing F003 and F005 wastes. Since the unused cleaning products would not be F003 or F005 wastes, they should not be covered by the proposed exception, and thus should remain eligible for the aqueous alcohol exclusion. (Of course, if the unused cleaning/solvent product contains isobutanol as the sole active ingredient, it would qualify as EPA Hazardous Waste No. U140. See 40 C.F.R. § 261.33(f). The other three alcohols at issue are not listed as commercial chemicals products, and thus would not be regulated in the same way. Id.) [Commenter 2]
-- Would used cleaning/solvent products containing one of the four alcohols no longer be eligible for the aqueous alcohol exclusion?
      These used cleaning/solvent products generally would qualify as spent solvents (except in some cases, such as if they could continue to be used as is), and thus might be classified as F003 or F005 wastes. However, this would not always be the case. For example, the F003 and F005 listings apply only to certain solvent mixtures/blends; they do not apply to other solvent mixtures/blends, even if they contain one of the four alcohols and such alcohols were included in the mixture/blend for their solvent properties. See, e.g., 40 C.F.R. § 261.31 (defining F005 to include "spent solvent mixtures/blends containing, before use, a total of ten percent or more (by volume) of one or more of the [F005] non-halogenated solvents [including isobutanol and 2-ethoxyethanol] or those solvents listed in F001, F002, or F004"). In addition, the F003 and F005 listings do not apply to wastewaters that contain listed spent solvents but that qualify for one of the mixture rule exemptions set forth in the regulations. See 40 C.F.R. §§ 261.3(a)(2)(iv)(B) (for wastewaters containing isobutanol or 2-ethoxyethanol spent solvents at levels below 25 parts per million on a weekly average basis at the headworks of a wastewater treatment system), (D) (for wastewaters containing de minimis losses of F003 or F005 wastes), and (E) (for wastewaters containing laboratory wastewaters with toxic listed wastes (presumably including F005 wastes even though such wastes also are listed for ignitability) if the laboratory wastewaters represent less than 1% of the flow at the headworks of the wastewater treatment system on an annualized basis).
      To the extent the used cleaning/solvent products would not be classified as F003 or F005 wastes, for the reasons discussed above or others, we believe they should not be covered by the proposed exception, and thus should remain eligible for the aqueous alcohol exclusion. However, because EPA did not address this issue in its proposal, it is unclear what the Agency intends in this regard. [Commenter 2]
-- How would the exception to the aqueous alcohol exclusion apply to wastes with more than one alcohol constituent?
      Under EPA's proposed exception, the aqueous alcohol exclusion would not apply if "the" alcohol in the waste is one of the four specified alcohols and it is used for its solvent properties. However, the proposal is silent with respect to wastes containing more than one alcohol. Presumably, if all the alcohols present are among the four specified alcohols and were used for their solvent properties, the proposed exception would kick in, and the aqueous alcohol exclusion would not apply. However, the regulated community is left to guess what the status would be if a waste contains one of the specified alcohols and another alcohol that is not specified (e.g., ethanol), or if a waste contains two of the specified alcohols and one of them is present for non-solvent purposes. [Commenter 2]
-- Would the exception to the aqueous alcohol exclusion apply to wastes containing ethanol denatured with methanol?
      We believe the answer would be "no," because ethanol is not one of the four specified solvents, and even though methanol is, it was used for its ability to denature the ethanol, not for its solvent properties. However, to the extent that the denatured ethanol was used as a solvent, questions might be raised as to whether the methanol was also being used, at least in part, for its solvent properties. The resulting confusion could create substantial problems, given that denatured ethanol is a ubiquitous solvent and methanol is a common denaturant.  [Commenter 2]
EPA's Proposal Would Effectively Repeal an Important Part of the Agency's Carefully Crafted 2001 Hazardous Waste Identification Rule:  In the 2001 Hazardous Waste Identification Rule ("HWIR")  -  after years of careful deliberation, including evaluation of public comments on proposals issued in 1995 and 1999  -  EPA issued a final rule stating that "all wastes listed solely for [the] ignitability ... characteristic (including mixtures, derived-from and as generated wastes) are excluded [from regulation] once they no longer exhibit a characteristic." See 66 Fed. Reg. 27,266, 27,268 (May 16, 2001). That rule is codified at 40 C.F.R. § 261.3(g). Under the rule, spent solvent wastes that would otherwise be classified as F003 wastes (e.g., spent methanol or n-butanol cleaning/solvent products) are not designated as such if they do not exhibit the characteristic of ignitability. See 40 C.F.R. § 261.31 (indicating that F003 was listed solely because of ignitability); 66 Fed. Reg. at 27,284-85 (discussing the applicability of the 2001 rule to F003 wastes). Of course, one way that such a waste might not exhibit the ignitability characteristic (as it has been defined since the beginning of the RCRA regulatory program, including 2001 and today) is if it qualifies for the aqueous alcohol exclusion. For example, if a spent methanol cleaning/solvent product has a low flash point but contains less than 24% alcohol and more than 50% water, it would not be ignitable (because of the aqueous alcohol exclusion) and it would not qualify as F003 (because of the 2001 HWIR rule).
      EPA's proposal, however, would lead to the opposite result, and thus would effectively repeal a key element of the HWIR rule. Under the proposal, the spent methanol cleaning/solvent product mentioned above would be deemed ignitable, since the aqueous alcohol exclusion would no longer apply. In addition, since the waste would be deemed ignitable, it would no longer be a waste listed for ignitability that doesn't exhibit a characteristic, and it would have to be designated F003. This is precisely the result that the 2001 HWIR rule was designed to prevent.
      While EPA may be entitled to repeal one of its prior rules, in order to do so it must provide clear notice of its intent, as well as a rational basis for the proposed change. The Agency has done neither here, and thus cannot move forward with its proposal.  [Commenter 2]
Codification of Guidance into the Ignitability Characteristic: Alcohol exclusion:  EPA's proposed changes to the alcohol exclusion will narrow the existing exclusion unnecessarily and represent a significant departure from existing practice in managing waste streams. EPA properly recognizes that the alcohol exclusion was originally intended to exclude from hazardous waste management requirements materials that exhibit low flash points due to their alcohol content, but do not sustain combustion. The Agency also notes that it is "unaware of existing mismanagement or damage cases" caused by the existing regulatory framework. It is not at all clear why the Agency now proposes changes that would place strict limits on the use of the exclusion, forcing expensive changes to current waste management practices with no commensurate human health or environmental benefit.
       EPA proposes to revise the aqueous alcohol exclusion by removing the term "aqueous," and limit the exclusion to "solutions containing less than 24 percent of any alcohol or combination of alcohols (except if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005) by volume and at least 50 percent water by weight." Existing guidance currently recognizes that "if the alcohol is one of those alcohols specified in EPA hazardous waste codes F001-F005 and has been used for its solvent properties, the waste must be evaluated to determine if it should be classified as an F listed spent solvent waste." Indeed, EPA has recognized that even wastes that meet the description for F003 spent solvents are not F003 wastes if they do not meet the ignitability characteristic. In addition, EPA has maintained that the exclusion also applies to wastes that contain a nonalcoholic component. The proposed language could be read to require, however, that any waste classified as F003 or F005 constitutes an ignitable hazardous waste. This presents a significant change to existing practice.
       EPA's proposed revision would result in the re-classification of millions of pounds of materials annually from non-hazardous to hazardous waste (HW) placing a significant burden on generators who have for decades managed those same materials safely, efficiently and cost-effectively. Some ACC members have informed us that this change could result in 28 or more different waste streams being re-classified from non-hazardous to hazardous. This could require approximately 123 million pounds per year of material to be handled, transported, treated and disposed of as HW at an estimated additional cost of $61 million annually. The potential costs of EPA's proposed revisions are significant and EPA has provided no sound policy or legal rationale to support its proposed revision. In fact, as noted above, EPA concedes that the existing alcohol exclusion has not resulted in adverse human health or environmental impacts.
       EPA's proposed changes also conflict with the DOT aqueous alcohol exclusion. Indeed, EPA recognized in the preamble to this proposal that the alcohol exclusion under the ignitability rule was "originally intended to be consistent with DOT regulations." The DOT aqueous alcohol exclusion currently defines an aqueous alcohol solution as one "containing 24 percent or less alcohol by volume", whereas EPA's proposed language would apply only to solutions with less than 24% alcohol.
       EPA should also avoid narrowing the exclusion and unnecessarily increasing the number of waste streams classified as hazardous. For example, EPA has requested comment on whether to "explicitly identif[y] specific waste streams" to which the exclusion would apply, limit the exclusion to certain types of alcohol, increase the minimum water content, or place a minimum alcohol content limit on the exclusion. Many of these changes, individually or in combination, would have significant cost implications for the management of waste streams that are not currently classified as hazardous.
       In light of these consequences, none of EPA's proposed changes to the implementation of the alcohol exclusion are justified, given the aforementioned lack of documented mismanagement or demonstrated risk to human health or the environment. However, in the event EPA makes any changes to the ignitability rule, EPA should be sure to recognize that the exclusion applies to F003 Methyl alcohol, F003 n-Butyl alcohol as well as U031 n-Butyl Alcohol and U154 Methyl alcohol. Extending the exclusion to these other alcohol ignitable listed wastes F003, U031 and U154 makes sense and would help eliminate unintended consequences and regulatory uncertainty of some listed waste mixtures.  [Commenter 4]
Aqueous Alcohol Exclusion:  Stericycle commends EPA for the proposal to narrow the alcohol exclusion so that aqueous liquids with small amounts of alcohol that are ignitable due primarily to non-alcoholic components are not excluded...In addition, we would encourage the incorporation of the exclusion for materials that do not sustain combustion to be included in the definition of an ignitable material, consistent with the DOT requirements of 49CFR 173.120 (a)(3) "Any liquid with a flash point greater than 35 °C (95 °F) that does not sustain combustion according to ASTM D 4206 (IBR, see §171.7 of this subchapter) or the procedure in appendix H of this part."  [Commenter 10]
In this same proposed 261.21(a)(1), the exception to the exception for F003 alcohols and F005 alcohols is wrong on a few different levels, and so should be replaced with an informational note stating that a waste qualifying for the <24% exemption is not exempted from separately being a F003 or F005 hazardous waste if it meets the F003 or F005 descriptions.
       The currently proposed language also wrongly suggests that the mere presence of one of the alcohols listed in the F003 or F005 descriptions makes it ineligible for the <24% exemption, and, furthermore, this same language implies that the mere presence of one of those alcohols automatically makes the liquid a F003 or F005. It is noted that the concise language of EPA's guidance RO# 13548 states it correctly: " The Agency notes, however, that if the alcohol is one of those alcohols specified in EPA hazardous waste codes F001-F005 and has been used for its solvent properties, the waste must be evaluated to determine if it should be classified as an F listed spent solvent waste."  [Commenter 12]
Aqueous Alcohol Exclusion:  The ETC commends EPA for the proposal to narrow the alcohol exclusion so that aqueous liquids with small amounts of alcohol that are ignitable due primarily to non-alcoholic components are not excluded. The proposal states that EPA is currently unaware of existing mismanagement cases attributable to the overbroad aqueous alcohol exclusion. 84 FR 12546 col. 3. However, ETC member companies report that TSD facilities frequently receive hazardous wastes not identified as ignitable under the exclusion despite the presence of ignitable organics. The lack of documented mismanagement is largely due to proper management by TSD facilities, despite the ambiguities in the current alcohol exclusion which EPA proposes to clarify.  [Commenter 14]
EPA's Proposed Revision to the Aqueous Alcohol Exclusion: CPAI supports EPA's proposal to modify the aqueous alcohol exclusion to clarify that an aqueous waste stream that contains a small concentration of an ignitable alcohol and a large concentration of an ignitable non-alcoholic component would not be excluded. EPA's current proposed revisions will limit the exclusion to its original intent and clarify the exclusion's intent by codifying EPA's existing guidance into the regulatory text...For instance, EPA should not identify specific waste streams in the regulation to which the exclusion would apply or narrow the types of alcohol that would qualify for the aqueous alcohol exclusion.  [Commenter 8]
EPA's Proposed Exception Is Unlawfully Ambiguous:  The proposal by EPA to establish an exception to the aqueous alcohol exclusion is so ambiguous that it fails to provide the regulated community adequate notice and opportunity to comment as required under the Administrative Procedure Act ("APA"). Moreover, if finalized, the proposed exception would not provide the regulated community "fair notice" of what would be regulated and therefore would violate constitutional standards of due process.
      In order to understand the ambiguities, it is first necessary to review the language of the proposed exception closely. Under EPA's proposal, the aqueous alcohol exclusion would not apply if (a) "the alcohol [contained in the waste] ... is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005," and (b) "the alcohol has been used for its solvent properties." With respect to (a), there are four alcohols specified in F003 and F005: methanol, n-butyl alcohol, isobutanol, and 2-ethoxyethanol. See 40 C.F.R. § 261.31. Thus, under EPA's proposal, if the alcohol in the waste is one of these four alcohols and it has been used for its "solvent properties," the aqueous alcohol exclusion would not apply.
      Unfortunately, the Agency does not define "solvent properties" in the proposal. Although EPA has previously indicated that "[chemicals] are used for their `solvent' properties [if they] solubilize (dissolve) or mobilize other constituents." see 50 Fed. Reg. 53,315, 53,316 (December 31, 1985), numerous uncertainties remain, including but not limited to the following: [Commenter 2]
EPA Has Not Provided Any Rationale for the Proposed Exception to the Aqueous Alcohol Exclusion:  In the preamble to the current proposal, EPA states that it is proposing the exception to the aqueous alcohol exclusion "to codify the existing guidance into the regulatory text." See 84 Fed. Reg. at 12,546. The Agency also indicates that the existing guidance that it is referring to is the 1990 preamble statement that "[i]f the alcohol has been used for solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005, the waste must be coded with these Hazardous Waste Numbers." See 84 Fed. Reg. at 12,546 and 12,543 (emphasis added), quoting 55 Fed. Reg. 22,520, 22,543 (June 1, 1990).
      To the extent that EPA might intend for its proposed exception to apply to wastes that contain one of the four alcohols but do not qualify as F003 or F005 wastes (for any of the reasons discussed above), the 1990 preamble clearly does not apply to such wastes. As noted above, since the 1990 preamble was discussing wastes that would need to be coded as F003 or F005, it had no relevance to wastes not covered by those codes. Thus, the 1990 preamble could not serve as a justification for EPA's proposal.
      Even if EPA intends that the proposed exception apply only to wastes that would otherwise qualify as F003 or F005 wastes, the 1990 preamble does not provide a justification. The 1990 preamble language was making the rather unremarkable statement that regardless of whether or not an alcohol-containing waste is ignitable, if it meets the definition of an F003 or F005 waste, it must be managed as such. This text was not intended to modify in any way the scope of the ignitability characteristic or the F003/F005 listings. Moreover, in the case of F003, the 2001 HWIR rule was intended to modify the relationship between the ignitability characteristic and the F003 listing, by providing that wastes that are not ignitable (e.g., due to the aqueous alcohol exclusion) no longer qualify as F003 wastes. EPA cannot justify undoing that 2001 rule simply by referring to guidance that predated the HWIR rule by more than a decade  -  especially since that guidance does not stand for principle EPA is now seeking to codify (and even if it somehow did, it was clearly superseded by the HWIR rule).  [Commenter 2]
The Retail Associations Do Not Believe Any Rationale Exists for the Proposed Exception to the Aqueous Alcohol Exclusion:  Under RCRA, any "regulations identifying the characteristics of hazardous waste ... shall be based on ... criteria [previously] promulgated [by EPA]." See 42 U.S.C. § 6921(b)(1), RCRA § 3001(b)(1). The referenced criteria are set forth in the RCRA regulations at 40 C.F.R. § 262.10, and specify that the Agency may "identify and define a characteristic of hazardous waste ... only upon determining that ... [a] solid waste that exhibits the characteristic may: (i) Cause, or significantly contribute to, an increase in mortality or an increase in serious irreversible, or incapacitating reversible, illness; or (ii) Pose a substantial present or potential hazard to human health or the environment when it is improperly treated, stored, transported, disposed of or otherwise managed." For a characteristic based on a physical hazard like ignitability, clause (i) clearly does not apply. Thus, in order for EPA to expand the ignitability characteristic, as it has proposed to do by narrowing the aqueous alcohol exclusion, the Agency must determine that the newly regulated wastes pose a "substantial ... hazard to human health or the environment. [Commenter 2]
The Retail Associations are not aware of any reason to believe that the wastes that would be newly classified as hazardous wastes under EPA's proposed narrowing of the aqueous alcohol exclusion pose a risk to human health or the environment. Indeed, the Agency itself acknowledges in the preamble to the current proposal that "EPA is currently unaware of existing mismanagement or damage cases" associated with these wastes. See 84 Fed. Reg. at 12,546. Moreover, EPA admits that it doesn't even know what wastes would be affected by its proposal. Id. (stating that the proposal "may only affect a small number of (currently unknown) waste streams"). Without such knowledge, there is no legal basis for EPA to proceed with its proposal. The Retail Associations believe that the Agency's limited resources are better spent addressing known hazards, rather than pursuing purely speculative risks to human health and the environment. [Commenter 2]
The Proposed Exception to the Aqueous Alcohol Exclusion Would Arbitrarily Result in Inconsistent Classification of Substantially Similar Wastes:  As noted above, the original basis for the aqueous alcohol exclusion was to ensure that wastes with low flash points would not be regulated as ignitable hazardous wastes if they are unable to sustain combustion. EPA's proposed exception would bring back into the RCRA regulatory program some of the currently excluded wastes, without any regard to their ability to sustain combustion. To illustrate the point, consider a series of aqueous wastes with less than 24% (say 20%) of the following alcohols used for their solvent properties: (a) methanol (with one carbon and a flash point of 12.2°C), (b) ethanol (with two carbons and a flash point of 12.7°C), (c) n-propanol (with three carbons and a flash point of 25°C), and (d) n-butanol (with four carbons and a flash point of 35°C). See Hawley's Condensed Chemical Dictionary (15th Edition, 2007) at 816, 518, 1048, and 194, respectively. All of these wastes would currently be excluded from regulation, but under EPA's proposal, (a) and (d) would be newly subjected to regulation (since they are solvents specified in the F003 listing)  -  even though the wastes with alcohols in the intermediate range between these two (in terms of chemical structure (number of carbons) and flash point) would continue to be excluded. This would be regulation without any rhyme or reason.
      Similarly, consider two aqueous wastes that contain 20% methanol, one of which contains methanol for its solvent properties, while the other contains methanol for another reason. Both of these wastes would currently be excluded from regulation, but under EPA's proposal the first one  -  and only the first one  -  would be newly regulated. Of course, both of them would be the same in terms of their ability to sustain combustion (assuming all the other constituents are the same); the ability to sustain combustion does not depend upon the reason why the methanol is present. Yet, EPA's proposal would treat the two identical wastes completely differently. There can be no justification for such an arbitrary rule.  [Commenter 2]

Response to Comments:
Thank you for your comments. The Agency is not finalizing the proposed language, "except if the alcohol has been used for its solvent properties and is one of the alcohols specified in EPA Hazardous Waste No. F003 or F005 in 40 CFR 261.31," due to the multiple interpretations from the public on its meaning. In proposing to amend 40 CFR §261.21(a)(1) to include this language, the Agency intended to clarify that generators are still responsible for identifying their waste as hazardous if the waste met relevant listing descriptions. The Agency did not intend for the proposed language to narrow the exclusion. The scope of the listings that contain alcohols, the scope of the aqueous alcohol exclusion, and interrelation between the two through the mixture and derived from rule all remain unchanged. See section III.D of the final rule for more discussion on the aqueous alcohol exclusion.

Additional Comments on the Aqueous Alcohols Exclusion
Comment Excerpts:
Other Potential Changes to the Aqueous Alcohol Exclusion:  EPA has asked for comment on a number of other potential changes to the aqueous alcohol exclusion that would have the effect of narrowing the exclusion and thereby expanding the universe of wastes classified as ignitable hazardous wastes. See 84 Fed. Reg. at 12,547. The potential changes mentioned by the Agency included limiting the exclusion to specific wastes or specific alcohols, increasing the minimum water content for exclusion above 50%, and establishing a minimum alcohol content (in addition to the maximum 24% alcohol limit) for eligible wastes. Id.
      The Retail Associations oppose the potential changes mentioned by EPA, for several reasons. As an initial matter, the Agency has not provided sufficient detail about the potential changes under consideration to enable the regulated community to provide meaningful comment. For example, EPA has not specified what wastes or alcohols would be kept in or removed from the exclusion, if the exclusion is limited to specific wastes or alcohols. Similarly, the Agency has not specified how far above 50% it might increase the minimum water content requirement, or how high or low a minimum alcohol content limit might be set. Without such details, the regulated community cannot fully assess the reasonableness of the changes mentioned by EPA, the potential impacts of such changes, etc.
      In any event, EPA has not offered any justification for making any of the potential changes. As noted above, an expansion of the ignitability characteristic would require a determination that the affected wastes pose a substantial threat to human health or the environment. The Agency has acknowledged that it is "unaware of existing mismanagement or damage cases" associated with the current alcohol exclusion, and that it doesn't know what wastes would be affected by a change to the exclusion. See 84 Fed. Reg. at 12,546. Under these conditions, there is no legal basis for EPA to proceed with any of these potential changes.  [Commenter 2]
We do not believe that EPA should make any additional changes to the alcohol exclusion at this time. 84 FR 12547, col. 1. For example, explicitly identifying specific waste streams in the regulation may be problematic. A specific list would be difficult to develop, potentially omit relevant waste streams, include wastes that are generally not ignitable, never be comprehensive, and therefore would not "remove the uncertainty" regarding the exclusion. Id. Also EPA should not try to narrow the types of alcohol that would quality for the exclusion, but should continue to use the general term "alcohol." Likewise, we do not recommend raising the minimum water content above 50% or adding a minimum alcohol content which would be disruptive and costly to our current waste identification procedures without sufficient benefit.  [Commenter 14]

Response to Comments:
Thank you for your comments. The Agency agrees that any other changes beyond EPA's specific proposed language would warrant further discussion and public input and, therefore, is not finalizing any changes to the aqueous alcohol exclusion at this time that were not proposed.

Comment Excerpt:
Among the changes proposed by EPA is a change to the aqueous alcohol exclusion for ignitability. Currently, at 40 CFR 262.21(a)(1), "an aqueous solution containing less than 24% alcohol by volume" is excluded from being regulated as an ignitable hazardous waste. The effect of this is that such a waste is not considered to exhibit the characteristic of ignitability even if the solution has a flash point below 140 degrees Fahrenheit. EPA is proposing to revise the aqueous alcohol exclusion to make the regulatory language consistent with interpretive guidance that EPA has provided over the years. EPA indicates in the preamble to the proposed rule, that, if the proposed revision to the exclusion is adopted, it will continue to be EPA's interpretation that an aqueous waste stream that contains a small concentration of an ignitable alcohol and a large concentration of an ignitable non-alcohol component would be excluded from the ignitability characteristic "despite potentially exhibiting the same hazards as ignitable wastes that do not fall within the scope of the exclusion."
       MDE believes that EPA needs to revisit the status, under the aqueous alcohol exclusion, of aqueous wastes that contain a small concentration of an ignitable alcohol and a large concentration of an ignitable non-alcohol component. Instead of endorsing a blanket exclusion from the ignitability characteristic for such wastes, EPA should add qualifiers to the exclusion so that the exclusion is consistent with the intended scope of the ignitability characteristic.
       One of the original justifications for including an exclusion from the ignitability characteristic for aqueous solutions that contain less than 24% alcohol by volume was that such solutions were not capable of sustaining combustion if ignited (45 FR 33108, May 19, 1980). EPA should clarify that an aqueous solution of an alcohol and an ignitable non-alcoholic material is not eligible for the aqueous alcohol exclusion if the aqueous solution of alcohol and other ignitable components is capable of sustaining combustion.
       In addition, for an aqueous solution that contains a non-alcohol ignitable component and alcohol at less than 24% alcohol by volume, EPA should establish that the exclusion does not apply if the fact that the flash point of the solution is less than 140 degrees Fahrenheit is attributable solely to the non-alcohol ignitable component. This would prevent the exclusion from applying to a solution with a non-alcohol ignitable component in which the concentration of alcohol is so low that the flashpoint for a two-component (alcohol/water) solution at that concentration of alcohol would have a flash point significantly above 140 degrees Fahrenheit.
       Such data for ethanol/water solutions is presented in a graph on page 64 of Ethyl Alcohol Handbook, 6th edition, Equistar Chemicals, LP, 2003 (accessed at <http://www.itecref.com/pdf/Ethyl_Alcohol_Handbook_Equistar.pdf> on 3/31/19). The data presented indicates that a flashpoint of 140 degrees Fahrenheit will be exceeded by an aqueous solution of ethanol of 8% or less alcohol by volume (closed cup test), or 11% or less alcohol by volume (open cup test), with the flash point climbing steeply as the percent alcohol by volume continues to decrease.
       In fact, the graph indicates that, for a closed cup text, at approximately 4% alcohol by volume, the curve of flash point versus percent alcohol by volume is essentially vertical. This indicates that, as alcohol concentrations fall below 4% alcohol by volume, the alcohol/water solution would most likely begin to vaporize before there is a positive result on a flash point test.
       The implication of this is that if a solution consists of water, ethanol at a concentration of less than 4% alcohol by volume, and some other ignitable component, and if that solution has a flash point of less than 140 degrees Fahrenheit, the low flash point is almost certainly attributable to the non-alcohol component. Designating such a solution as being eligible for the aqueous alcohol exclusion would appear to be a loophole that could allow disposal of hazardous wastes as nonhazardous. It might also encourage persons to attempt to circumvent hazardous waste regulations by constructing ignitable solutions with minimal concentrations of alcohol.
       References to other sources of data on the flash points of binary solutions of alcohol and water, as well as theoretical methods of calculating flash points of mixtures can be found by performing an internet search using the search terms <flash point determination of binary mixtures of alcohols and water>.  [Commenter 7]
Response to Comments:
Thank you for your comment. The Agency agrees that there may be waste streams that warrant further examination for their suitability to be managed as an aqueous alcohol. The data provided by the commenter on aqueous ethanol illustrates this point. However, waste streams are often more complicated than binary mixtures of alcohol and water. A waste may have several chemical components that contribute to a low flash point value and present a risk to human health and the environment. A systematic methodology or test method would be needed to address the variety of potential wastes that might exhibit ignitability. At this time, the Agency is not finalizing any new criteria that would change the scope of the aqueous alcohol exclusion without further consideration of the affected waste streams and capabilities of existing test methods.

Identification of Multiple Phase Wastes
Comment Excerpt:
EPA has proposed to clarify procedures for sampling multiphase wastes relating to ignitability testing. AFPM supports this revision as it would codify existing guidance and appears to be what labs are already doing.  [Commenter 1]
The Separation of Multiphase Mixtures to Test Phases Individually is Appropriate: API agrees with EPA's statement that "a generator and laboratory should separate the sample into all of its different solid and/or liquid phases, to the extent practicable, and analyze each one individually ... to determine whether that phase exhibits the characteristic of ignitability." see 84 Fed. Reg at 12,547. Testing of multiphase materials may lead to inconsistent and unreliable flash point results. [Commenter 6]
Response to Comments:
Thank you for your comments. While EPA is not finalizing its proposed language on sampling multiphase wastes at this time, the Agency agrees that samples for laboratory analysis should be separated into phases, when practical, for analytical purposes. See section III.E of the preamble for more discussion.

Comment Excerpts:
The Retail Associations Oppose the Proposed Changes to the Regulations and Guidance with Respect to Multiphase Wastes:  EPA has proposed a new provision that would classify "multiphase mixtures" as ignitable hazardous wastes if "any liquid phase [in the waste] has the flash point described in paragraph (a)(1) [i.e., less than 60°C (140°F)], or any non-liquid phase has the properties described in paragraph (a)(2) [i.e., if such phase is capable of causing a vigorous and persistent fire through friction, absorption of moisture, or spontaneous chemical changes]." See 84 Fed. Reg. at 12,552 (proposed to be codified at 40 C.F.R. § 261.21(a)(5)). The Agency has also proposed modifying its guidance manual on testing of solid wastes (commonly known as "SW-846") to specify that "[t]he definitive procedure for determining if a waste contains a liquid for the purposes of the ignitability and corrosivity characteristics is the pressure filtration technique specified in Method 1311." Id. at 12,548. The Retail Associations oppose both proposals, for the reasons discussed below.  [Commenter 2]
New Regulatory Provision for Multiphase Mixtures:  As noted above, EPA's first proposal with respect to multiphase wastes is adding a new provision stating that multiphase mixtures are hazardous if any liquid phase has a low flash point, or if any non-liquid phase meets the standards for ignitable non-liquids. The Retail Associations' objections to this proposal are as follows: [Commenter 2]
                EPA's Proposed New Provision for Multiphase Mixtures Is Unlawfully Ambiguous:  EPA's proposal to issue a new regulatory provision for multiphase mixtures does not define the mixtures to which it would apply, and therefore fails to provide the regulated community adequate notice and opportunity to comment as required under the APA. Moreover, if finalized, the proposed provision would not provide the regulated community "fair notice" of what would be regulated and therefore would violate constitutional standards of due process.
               The preamble to the proposed rule does describe "multiphase wastes" as "wastes that, due to differences in density (e.g., oil/water) or physical form (e.g., solid/liquid), separate into two or more phases." See 84 Fed. Reg. at 12,547. However, it is unclear whether multiphase mixtures (the term used in the proposed regulatory text) are the same as the multiphase wastes described in the preamble. The word "mixture" is typically reserved under the RCRA regulations for a combination of two or more wastes after they have been separately generated, not a single as-generated waste. See, e.g., 40 C.F.R. § 261.3(a)(2)(iv). It is unclear, however, whether EPA, in fact, intends the proposed provision to be limited to such waste combinations.
               In either event, the preamble description of multiphase wastes refers to "wastes that ... separate." That language suggests that it is limited to wastes that separate on their own, without human intervention; it notably does not refer to "wastes that can be separated." Yet, in the proposed change to SW-846 (discussed in more detail below), EPA indicates that a solid-phase waste should be deemed to contain a liquid requiring separate testing if a liquid can be forced out through an aggressive pressure technique performed in a laboratory. That seems inconsistent with the preamble description of multiphase wastes, leaving the Retail Associations, and the regulated community more broadly, to wonder what EPA intends to regulate. [Commenter 2]
                EPA's Proposed New Provision for Multiphase Mixtures Would Be Inconsistent with the Aqueous Alcohol Exclusion:  Under the proposed rule, multiphase mixtures would be classified as ignitable hazardous wastes if any liquid phase in the waste "has the flash point described in paragraph (a)(1) [i.e., less than 60°C (140°F)]." Importantly, this language does not incorporate an aqueous alcohol exclusion, as the rule for (purely) liquid wastes does. EPA has not offered any justification for this omission, and the Retail Associations cannot perceive of any. We are also concerned that since many/most liquid wastes may have a small amount of filterable solids in them (and therefore could potentially be deemed multiphase wastes), applying a strict flash point test for multiphase mixtures, without an aqueous alcohol exclusion, would effectively eviscerate the exclusion.
               One way to avoid these problems would be to modify the proposed provision to say that multiphase mixtures are ignitable if any liquid phase "has the properties described in paragraph (a)(1) [i.e., the provision for ignitable liquids]." This language would also have the advantage of being parallel to the portion of the proposed new provision that relates to non-liquid phases with ignitable properties. As noted above, however, the Retail Associations urge EPA not to finalize the provision for multiphase mixtures at all.  [Commenter 2]
       Codification of Guidance into the Ignitability Characteristic: Multiphase wastes:  ACC is concerned that EPA's proposal to require sampling of each phase of a "multiphase mixture" is too rigid, and would cause confusion among the regulated community. Specifically, the Agency proposes that if any liquid or non-liquid phase of a mixture meets its respective test for ignitability, the mixture as a whole must be classified as ignitable. Under the proposal such "existing sampling procedures for multiphase samples would be applicable to all liquid wastes tested under 261.21."
       EPA's proposed approach for multiphase testing runs counter to its stated objective to modernize the rule and provide flexibility by imposing inflexible requirements on regulated entities. In many circumstances, testing of solid/liquid materials is complicated. Even under EPA's existing guidance, there is no current consensus as to which phases of a mixture should be tested for flash point to best determine ignitability. Such determinations are negotiated between the parties involved, and may already be dependent upon state requirements.
       Moreover, EPA's proposal ignores potential advances in testing and applies too broadly. For example, the Agency's guidance merely suggests these actions for particular types of mixtures, not all existing and possible mixtures. EPA's proposal presumes that since guidance has suggested both phases be separated and tested separately under some circumstances, that a requirement to do so for all mixtures would be more beneficial and would comport with all existing and future scientific standards. As evidenced by advances in flash point testing methodologies, and all manner of scientific advances, the best method of determining whether liquid is present in a waste, and of testing the respective phases for ignitability, may change drastically. EPA's proposal ignores these possible advances in favor of imposing inflexible requirements. [Commenter 4]
       EPA should avoid finalizing prescriptive standards for determining whether free liquid is present in a waste. Currently, industry utilizes multiple tests to determine the presence of liquid, including both the pressure filtration test, and the paint filter test, with many opting for the latter. In addition, such a change could result in the Agency requiring unnecessary testing on a wide variety of wastes that appear solid, and would not normally be subject to testing, to see if any free liquid can be removed by means of pressure filtration.
       Finally, EPA fails to appropriately account for which wastes qualify as a "multiphase mixture." The time it takes for a mixture to separate may vary drastically, and the proposal does not provide clarity as to which methods, and under what timeframe, a waste should be separated. Moreover, the regulated community has long understood that waste analysis under RCRA is supposed to be done at the point of waste generation.  [Commenter 4]
Response to Comment:
Thank you for your comments. The proposed language for multiple phases wastes is not being finalized as part of this action. The Agency agrees with the public commenters that indicated the current practices in analytical laboratories are to separate the phases of multiple phase wastes and analyze each phase separately. The Agency believes the measurement of the flash point of multiple phase mixtures within a flash point device would present significant analytical challenges. To address the confusion caused by the proposed language on sampling of multiple phase wastes as indicated by some of the comments, the Agency is instead reiterating and clarifying the existing Agency guidance for hazardous waste determinations of multiple phase wastes. See section III.E of the preamble for further explanation.

Comment Excerpt:
       Guidance on multiphase materials:  EPA is proposing to add 40 CFR 261.21(5) which they state would codify long standing guidance on how to test multiphase wastes. The proposed language is
            (5) It is a multiphase mixture, where any liquid phase has the flash point described in paragraph (a)(1) of this section, or any non-liquid phase has the properties described in paragraph (a)(2) of this section.
       In the preamble (12,547), the Agency states
            EPA's existing guidance on multiphase mixtures, which applies at initial generation and during the course of normal management, as applicable, in SW - 846 states to break up and separate phases when possible (SW - 846 Chapter 2, pp 8 - 9).
       However, when one goes to Chapter 2, the guidance on multiphase samples is not quite as simple as depicted in either the preamble or proposed language. The language from the guidance is as follows.
            <IP_ADDRESS> Multiphase samples
            Choice of the procedure for separating multiphase samples is highly dependent on the objective of the analysis. With a sample in which some of the phases tend to separate rapidly, the percent weight or volume of each phase should be calculated and each phase should be individually analyzed for the required analytes.
            An alternate approach is to obtain a homogeneous sample and attempt a single analysis on the combination of phases. This approach will give no information on the abundance of the analytes in the individual phases other than what can be implied by solubility.
            A third alternative is to select phases of interest and to analyze only those selected phases. This tactic must be consistent with the sampling/analysis objectives or it will yield insufficient information for the time and resources expended. The phases selected should be compared with Figure 2.1 and Table 2-41 for further guidance.
       As can be seen from section <IP_ADDRESS>, the guidance allows for three alternatives depending upon the objectives of the analysis. It does not require the laboratory to "break up and separate phases when possible" as stated in the preamble but gives the facility three options depending upon the objectives of the analysis. CRWI does not have a concern about the language in the guidance document. We believe the three options in the guidance document give facilities the flexibility to match the test to the objectives of the analysis. However, we are concerned that both the regulatory language and the preamble language will force facilities to always separate the phases before testing for ignitability. We do not believe that the Agency intended to restrict these options but are concerned that the proposed language inadvertently does so. As such, we suggest that the Agency clearly state in the preamble of the final rule that all three options listed in the guidance are allowed, depending upon the objectives of the analysis, and make the following modifications to paragraph (5).
            (5) It is a multiphase mixture, where any liquid phase has that meets the flash point criteria described in paragraph (a)(1) of this section, or any non-liquid phase has the properties described in paragraph (a)(2) of this section.   [Commenter 9]
Response to Comment:
Thank you for your comments. The Agency is not finalizing the proposed language for sampling of multiple phase wastes. The Agency does not require waste generators to physically separate wastes for management of the waste. To respond to the commenter's concerns, the Agency discusses the applicability of the three sampling approaches described in Chapter 2 of SW-846 to waste that exists in multiple phases in section III.E of the final rule.
Comment Excerpt:
Multiphase Waste Sampling:  ETC member companies have a great deal of experience managing multiphase wastes, and our WAPs specify sampling procedures and test methods for making ignitability determinations based on the current regulation and guidance. We cannot conclude that the proposed revisions on multiphase waste will "clarify" the existing sampling procedures as the Agency intends, but instead will add confusion and uncertainty.
       The current regulation already states that a hazardous waste determination must be made, not only at the point of waste generation, but also when the waste has changed its properties during management such that the RCRA classification of the waste may have changed. 40 CFR § 262.11(a). This regulatory language provides TSD facilities with the necessary flexibility to assess during management, which generally means upon receipt and during storage, whether a waste has separated into phases such that one of the phases in the waste may exhibit the characteristic of ignitability. EPA's guidance on when to separate a multiphase waste sample into its different solid and/or liquid phases for analysis "to the extent practical" is useful guidance, but not a mandatory requirement. State permit writers and compliance officials can apply guidance in a flexible manner depending on what is "practical."
       Many WAPs have tailored provisions for sampling and testing of multiphase waste for fingerprint analysis, such as testing the top organic phase most likely to be ignitable. In addition, when a multi-phasic waste has separated, it is usually the organic phase that will exhibit the ignitability characteristic and not the aqueous, non-organic phase. The point is that the current regulations and guidance allow TSD facilities to use practical experience to determine when a waste may separate into different phases during management, and whether such phase separation affects its hazardous waste characteristic, to safely address the situation. We should point out that properly assessing waste for ignitability also ensures that such wastes are safely handled at TSD facilities during management as "flammable" in compliance with National Fire Protection Association (NFPA) codes and standards.
       EPA's proposal to add a new paragraph (5) to § 261.21(a) will introduce new and burdensome issues of interpretation and application. The proposed paragraph begins by stating it applies to a waste that is already deemed "a multiphase mixture," raising practical questions of exactly when and how that determination is made for each particular waste. The preamble states that the proposed regulatory language will clarify that multiphase wastes "should" be separated into its different liquid and/or solid phases "to the extent possible," 84 FR 12547 col. 2, but no such qualification appears in the actual language of new paragraph (5). In other words, the flexibility provided in the preamble language does not appear in the regulation itself. ETC companies want to ensure that EPA is not interpreting the new paragraph (5) as a requirement that phases "must be" separated and tested individually.
       As the examples below illustrate, a requirement to separate all phases in a multiphasic mixture and test each phase individually will impose an undue testing burden on generators and laboratories by needlessly multiplying the number of tests that need to be performed:
             A liquid (e.g. paint) with some sludge on the bottom requires pouring off the liquid and running a flash point. If the result is <140[o] F, the entire mixture is a D001 waste. There is no reason to assess the ignitability of the sludge.
             A liquid with 5% solids requires running a flash point on the liquid containing the small amount of solids using a Pensky Martin tester that stirs the sample during the flash point analysis. Thus, the "multiphase mixture" is tested as a liquid with no reason to separate the solids and make a separate determination for them. The same approach applies to a liquid containing 10 or 15% solids.
             A multiphased liquid (organic liquid/aqueous liquid) with sufficient volume in the organic phase requires separating the organic phase, running a flash point on it and making a determination. Running a flash point analysis on the aqueous phase of this mixture is not necessary, as the entire mixture will be determined to be an ignitable waste if the organic phase flashpoint is <140[o] F.
             There is no single test method with a clear pass/fail for evaluating the flash point of a solid phase separated from a multiphase mixture like there is for evaluating the flash point of a liquid (pass/fail set at 140[o] F). The criteria in § 261.21(a)(2) would need to be applied to evaluate solids separated from a multiphasic mixture.
             There is no practical way to separate enough free liquid from a sludge with a minimal amount of free liquid to run a flash point analysis on the liquid phase of that sludge.
       It should be noted that a multiphase waste such as a sludge that contains free liquid would likely fail the paint filter test, be classified as a liquid and hence be subject to paragraph (a)(1), even though it may not be practical or even possible to separate enough liquid to perform a flash point test on just the liquid phase. The appropriate flash point method (Pensky-Martin with the sample stirred during testing or Setaflash with no stirring during testing) is best determined based on the characteristics of the multiphase mixture (liquid with a small amount of solids or sludge with minimal free liquid). The method selected for such multiphase "liquids" as well as the determination of which phase(s) to test for ignitability should be left to the expertise of the TSD facilities and the requirements included in their WAPs. Paragraph (a)(5) does not add any guidance beyond the techniques currently employed and removes the necessary flexibility expressed in the preamble discussion.  [Commenter 14]
Response to Comment: Thank you for your comments. The Agency is not finalizing the proposed language for sampling of multiple phase wastes. The Agency explains in the preamble how the guidance from Chapter 2 of SW-846, and other guidances, apply to identification of ignitable wastes. See section III.E of the final rule.

Comment Excerpt:
Similarly, it is unclear to what extent, if any, the preamble description of multiphase wastes or the proposed regulatory provision for multiphase mixtures is intended to apply to solid-phase manufactured articles that contain minute amounts of liquids, either in encapsulated form (e.g., the electrolyte in a small sealed battery) or in unencapsulated form (e.g., a few drops of lubricating liquid in a small mechanical device). At one point in the preamble, EPA states that laboratories should separate and test the different phases of a waste "to the extent practicable." See 84 Fed. Reg. at 12,547. Perhaps in these cases, separation would not be deemed practicable, such that the minute amounts of liquids would not have to be evaluated separately. Indeed, these articles would likely "pass" the Paint Filter Liquids Test and the Pressure Filtration Technique (discussed in more detail below), suggesting that the liquids would not have to be tested or evaluated separately. However, it is unclear what the Agency intends in this regard, or how EPA and state regulators would apply the proposed rule in practice. [Commenter 2]
 To the Extent that EPA May Intend to Regulate Manufactured Articles with Minute Amounts of Liquids as Multiphase Mixtures, Its Proposal Has Not Been and Cannot Be Justified:  As discussed above, EPA cannot expand the ignitability characteristic unless it is able to demonstrate that the wastes that would be brought into the RCRA regulatory program as a result pose a substantial risk to human health or the environment. EPA has not made such a showing for manufactured articles that contain minute amounts of liquids. Nor do we believe such a showing is possible. Even if such liquids might have a low flash point (and are not eligible for the aqueous alcohol exclusion), minute quantities surrounded by much larger amount of solids would likely never be able to sustain combustion (even in the unlikely event that that they might flash in the first instance). Accordingly, there is no basis for classifying these articles as hazardous wastes. [Commenter 2]
                To the Extent that EPA May Intend to Regulate Manufactured Articles with Minute Amounts of Liquids as Multiphase Mixtures, Its Proposal Would Have Substantial Adverse Effects on the Retail Sector:  In the event that EPA intends to regulate manufactured articles with minute amounts of liquids as multiphase wastes, its proposal would impose substantial new burdens on the retail sector, without any corresponding environmental benefits. Retailers often will not know if the manufactured articles they handle contain minute amounts of liquids, and even if they do, they are not generally in a position to know whether such liquids would meet the ignitability criteria. In addition, testing by retailers would not be practical, given that testing requires substantial quantities of materials (e.g., 75 g) and large numbers of articles would need to be destroyed to harvest the necessary amount. Manufacturers of the articles might be in a better position to know this information or to test the materials, but that isn't necessarily the case, and in any event it may be difficult for retailers to obtain the information (particularly, but not only, for imported goods). For example, information about minute amounts of liquids in manufactured articles are not required to be provided on safety data sheets.
               As discussed in more detail in Section 7.1 below, the effort to perform or obtain these evaluations for all of the potentially affected products would be a substantial burden for the retail sector and/or its suppliers. In some instances, the results could change the regulatory status of many retail facilities, thereby imposing much greater costs. EPA has not considered any of these costs, and it is doubtful that they would be justified, for the reasons discussed above.  [Commenter 2]
Response to Comment:
Thank you for your comment. The Agency is not finalizing the proposed language for sampling of multiple phase wastes as further discussed in section III.E of the preamble. EPA notes that, in the event that a waste has a small amount of potentially ignitable liquid within a large amount of non-ignitable solid, a generator should carefully evaluate the representative sample of the waste. The representative sample and its properties will depend on the specifics of the waste, and a generator may want to consult with their local regulatory authority on the specific facts of their waste.

Comment Excerpt:
EPA Must Provide Sufficient Guidance on How to Determine if a Waste is Multiphase: API believes that EPA fails to provide sufficient guidance for how and when to determine if a multiphase waste must be separated. EPA proposes codifying sampling guidance for multiphase waste "which are wastes that, due to differences in density (e.g., oil/water) or physical form (e.g., solid/liquid), separate into two or more phases." see id. The current regulations also require that characteristic determinations be made at the point of "generation, before any dilution, mixing, or other alteration of the waste occurs, and at any time in the course of its management that it has, or may have, changed its properties as a result of exposure to the environment or other factors that may change the properties of the waste such that the RCRA classification of the waste may change." It is not clear how much separation must occur in a waste for it to be considered "multi-phase", and whether the waste must be capable of achieving such separation on its own, without additional processes. Wastes such as stable emulsions, or small amounts of liquids contained with a solid would not likely separate on their own through normal management practices and handling time.  [Commenter 6]
Response to Comment:
Thank you for your comments. The Agency is not finalizing the proposed language for sampling of multiple phase wastes. The Agency explains in the preamble how the guidance from Chapter 2 of SW-846, and other guidances, apply to identification of ignitable wastes. See section III.E of the final rule.

Pressure Filtration and Ignitable Liquids
Comment Excerpts:
Proposed Change to SW-846 for Determining When Solids Contain Liquids:  EPA's second proposal with respect to multiphase wastes is to add language to SW-846 specifying that "[t]he definitive procedure for determining if a waste contains a liquid for the purposes of the ignitability and corrosivity characteristics is the pressure filtration technique specified in Method 1311." See 84 Fed. Reg. at 12,548. As discussed above, this proposal is at odds with the description of multiphase wastes in the preamble to the proposal as "wastes that separate" by themselves, without human intervention. In addition, the Retail Associations oppose this proposal on several other grounds, as discussed below:
             EPA Has Not Provided Any Rationale for Its Proposed Guidance on Free Liquids, and the Retail Associations Doubt Any Rationale Exists:  In the preamble to the current proposal, EPA did not say much about the proposed guidance on assessing free liquids, other than to note that it proposed similar guidance in 1993 but decided in 1995 not to finalize that proposal. See 84 Fed. Reg. at 12,548, discussing 58 Fed. Reg. 46,052 (August 31, 1993) (proposal) and 60 Fed. Reg. 3089 (January 13, 1995) (decision not to finalize the proposal). That is hardly a justification for proceeding with the same guidance now. Clearly, the Agency has not demonstrated, or even attempted to demonstrate, that the proposed guidance is necessary to protect human health and the environment.
            The Retail Associations do not believe that the current proposal is warranted. If a waste passes the Paint Filter Liquids Test, it should be sufficient to evaluate the potential ignitability of the waste under the standard for non-liquids. Indeed, this is the position that EPA itself has long taken. For example, the RCRA regulations prohibit the placement of free liquids in landfills, and specify that the Paint Filter Liquids Test must be used "[t]o demonstrate the absence or presence of free liquids." See 40 C.F.R. §§ 264.314(b) and 265.314(b); 50 Fed. Reg. 18,370 (April 30, 1985) (promulgating these provisions and explaining the basis for use of the Paint Filter Liquids Test). In 1990, EPA stated that "in determining whether a waste is `liquid' ... for the purpose of ignitability or corrosivity testing ... [t]he generator of the waste may use any method for which he can provide appropriate scientific or technical justification. The Agency ... is generally willing to accept test results from the use of Method 9095, the `paint filter' test." See Letter from Sylvia K. Lowrance, Director, Office of Solid Waste, EPA, to Robert D. Wyatt (February 16, 1990) (RCRA Online #13352).
            Even after the last document cited by EPA in the current proposal (i.e., the January 13, 1995 decision not to finalize the proposed guidance on use of the Pressure Filtration Technique), the Agency stated that "the Paint Filter test is the method to use to determine if a free liquid is present for ignitability determination" and indicated that this would continue to be the case unless and until EPA issued a final rule to the contrary. See Letter from David Bussard, Director, Characterization and Assessment Division, Office of Solid Waste, EPA, to Charles D. Duthler, ICI Composites, Inc. (January 26, 1995) (RCRA Online #11935). Because that appears to be the last EPA statement on the issue, and because a final rule to the contrary has obviously not been issued, the Paint Filter Liquids Test has been the test authorized by EPA guidance for the last 20+ years (and well before that). Moreover, as discussed immediately below, the Agency issued a final rule in 2013 mandating use of the Paint Filter Liquids Test for determining whether solvent-contaminated wipes (including those contaminated with ignitable solvents) are subject to RCRA regulation. There is no apparent reason for now switching tests, and EPA has not offered one.
             EPA's Proposal Is Inconsistent with the 2013 Rule on Solvent-Contaminated Wipes:  In 2013 - after decades of deliberation and analysis, including consideration of rulemaking petitions in 1985 and 1987, the results of the Agency's Common Sense Initiative of the 1990s, and evaluation of public comments on proposals and notices of data availability issued in 2003 and 2009  -  EPA issued a final rule establishing regulatory exclusions for used solvent-contaminated wipes (including those contaminated with ignitable solvents) that have "no free liquids" when sent for recycling or disposal. See 78 Fed. Reg. 46,448 (July 31, 2013) at 46,449-54 (discussing the history of the rule) and 46,484-85 (codifying the final exclusions at 40 C.F.R. §§ 261.4(a)(26) and (b)(18)). For these purposes, the Agency defined "no free liquids" by reference to the Paint Filter Liquids Test, explicitly choosing not to adopt the Pressure Filtration Technique. See id. at 46,467; 40 C.F.R. § 260.10 ("No free liquids ... means that solvent-contaminated wipes may not contain free liquids as determined by Method 9095B (Paint Filter Liquids Test)").
            EPA's proposal to add guidance to SW-846 specifying that the Pressure Filtration Technique is the only "definitive" way to determine whether liquids are present, for ignitability purposes, is clearly inconsistent with the 2013 Wipes Rule. Since EPA has determined that the Paint Filter Liquids Test is the proper test for determining whether used solvent-contaminated wipes contain liquids that must be evaluated for ignitability, that same test should be appropriate for other wastes. EPA has not offered any reason for applying a different "no free liquids" standard to different categories of wastes, and the Retail Associations do not believe any such reason exists. This is especially true with respect to wastes that are substantially the same as the used solvent-contaminated wipes covered by the 2013 Rule, such as unused pre-moistened wipes or wipes contaminated by liquids other than solvents. See 40 C.F.R. § 260.10 (definition of "solvent-contaminated wipe").
            The Agency also has not explained how it envisions the proposed new guidance would relate to the 2013 Wipes Rule. Presumably, the rule on solvent-contaminated wipes would take precedence, since it is a formal rule (rather than mere guidance) and more specific. However, the conflicting statements would undoubtedly lead to confusion in the regulated community, and it might be an invitation to arbitrary enforcement.
             To the Extent that EPA May Be Planning to Apply Its Proposed Guidance to Corrosive Wastes, the Agency Has Not Provided Adequate Notice and Opportunity to Comment, and the Guidance Would Be Similarly Flawed:  The language that EPA appears to be proposing for addition to SW-846 could potentially address "EPA's position on determining free liquids" not only for purposes of the ignitability characteristic, but also for purposes of the corrosivity characteristic. See 84 Fed. Reg. at 12,548. However, EPA has hidden the ball on this issue. The proposal is entitled "Modernizing Ignitable Liquids Determinations," providing no hint that the corrosivity characteristic might be affected. Indeed, the potential application of the proposed guidance to corrosive wastes can only be loosely inferred from a single statement buried near the end of the proposal. Id. In this way, the regulated community has been denied adequate notice of EPA's intent, and has been denied a meaningful opportunity to comment. If, in fact, EPA is intending to extend its proposed guidance to corrosive wastes, such an extension would be improper for much the same reasons that the guidance is inappropriate for ignitable wastes (as discussed above).
             The Proposed Guidance on Free Liquids Would Have Substantial Adverse Impacts on the Retail Sector:  Retailers frequently generate a variety of wastes that could potentially be affected by EPA's proposed guidance on when solids contain liquids that need to be evaluated separately for ignitability (and possibly corrosivity) purposes. One type of waste that might be especially affected is unused pre-moistened wipes or other applicators (e.g., cotton swabs). Such wipes and applicators are sold in stores for an exceptionally wide range of applications, such as for medical/sterilization purposes (e.g., individually wrapped alcohol pads), cleaning, personal care, and application of surface treatments, pesticides, and pharmaceuticals. Retailers may generate these items as wastes in certain circumstances, such as if the products are damaged, expired, discontinued, or returned by customers (e.g., in a slightly used pack). In essentially all cases, these products would be expected to pass the Paint Filter Liquids Test. However, it is not readily obvious how these products would fare under the Pressure Filtration Technique. It seems possible that some of these products, if subjected to the aggressive pressure required under that Technique, might express a small amount of liquid, which might then have to be tested for ignitability (and possibly corrosivity). As discussed in more detail in Section 7.1 below, performing these evaluations on all of the potentially affected products would be a substantial burden for the retail sector and/or its suppliers. In some instances, the results could change the regulatory status of many retail facilities, thereby imposing much greater costs. EPA has not considered any of these costs, and it is doubtful that they would be justified, for the reasons discussed above.
            One other important type of waste generated by retailers that might be affected by EPA's proposal on free liquids is absorbents used to clean up minor spills. It is generally easy to make an on-the-spot determination that used absorbents do not contain free liquids under a Paint Filter Liquids Test. However, a determination under the Pressure Filtration Technique might not be susceptible to such simple judgments. Thus, retailers might have to either have the absorbents tested or manage them all as liquid-containing wastes. Once again, this would impose substantial costs on the industry, without any discernable environmental benefit.  [Commenter 2]
The Use of the Pressure Filtration Test to Determine if a Waste Contains Liquid is Unwarranted: API does not support the use of a pressure filtration test under SW-846 to determine if a solid waste contains liquid and should be subject to a flash point and/or corrosivity test. This goes against the Agency's past position that the paint filter test is the proper method to use to determine if a free liquid is present for ignitability determination. Similar to the concern regarding the separation of multiphase waste, the use of a pressure filtration test could incorrectly classify more waste as ignitable (or corrosive). A waste may never have a liquid phase separate through normal management practices and handling time, but the pressure filtration test may force this separation.  [Commenter 6]
Pressure Filtration Test:  ETC companies have had very poor experience with pressure filtration techniques to determine free liquids in hazardous wastes, and therefore strongly oppose adding the proposed guidance to SW-846 for both ignitable and corrosive wastes. 84 FR 12548, col. 1. Much of the hazardous waste managed at TSD facilities is sludgy, viscous, messy waste, thus making it difficult to use pressure filtration. In fact, using this technique may not even yield enough liquids from many wastes to be able to run an ignitability test. As a practical matter, pressure filtration requires too much handling of the waste by laboratory and facility personnel, resulting in laborious cleanup and disposal of sticky, onerous residue. This is especially true for corrosive wastes that can present serious risk from excess handling. Nothing in the proposed rule even discusses the practical problems with using pressure filtration techniques for multiphase ignitable and corrosive wastes. EPA did not finalize this proposed addition to SW-846 in 1993, and it should not do so now without specifically addressing these concerns.  [Commenter 14]
Response to Comments:
Thank you for your comments. The Agency asked for public input on the use of the Pressure Filtration Procedure but did not specifically propose any language requiring its use with regard to ignitability determinations. The Agency is not finalizing any language related to the Pressure Filtration or Paint Filter Liquids Test in this final rule. However, the Agency discussed the application of existing guidance and policy in section III.F in the final rule. Corrosive wastes do not fall within the scope of this action.

Economic or Regulatory Impacts
Comment Excerpts:
The Proposed Exception to the Aqueous Alcohol Exclusion Would Have Substantial Adverse Impacts on the Retail Sector:  Because there is so much uncertainty about what EPA's proposed exception to the aqueous alcohol exclusion would mean, it's difficult to say exactly what wastes might be affected. However, as discussed above, the status of an extremely wide range of wastes could potentially change, including large numbers of commercial products managed by retail facilities (e.g., inks, paints, dyes, stains, coatings, cleaning products, and fragrances). To the extent that this might be the case, retailers would be required to perform new hazardous waste determinations for all the potentially relevant wastes. As discussed in more detail in Section 7.1 below, the costs of performing these evaluations would be a substantial burden for the retail sector and/or its suppliers. In some instances, the results could change the regulatory status of many retail facilities, thereby imposing much greater costs. EPA has not considered any of these costs, and it is doubtful that they would be justified, for the reasons discussed above.  [Commenter 2]
The Retail Associations Strongly Disagree that EPA's Proposal Would Have No Significant Economic Impacts:  In the preamble to the current proposal, EPA states that "[t]his is not a significant regulatory action because it does not have significant economic impact." See 84 Fed. Reg. at 12,550. The Retail Associations strongly disagree. As discussed above, several of the changes to the ignitability characteristic that EPA has proposed or asked for comment on have the potential to change substantially the regulatory status of a wide range of wastes, such as aqueous alcohol wastes, manufactured articles with minute amounts of liquids, unused pre-moistened wipes that are discarded, and used absorbents. As a result, generators of such wastes  -  including those in the retail industry  -  will have to perform new hazardous waste determinations for all potentially affected wastes, which will obviously entail significant new costs. Any wastes found to be newly hazardous will also have to be managed as hazardous wastes for the first time, which will entail additional costs. Moreover, in some cases, the newly hazardous wastes will change the status of the generators (e.g., from VSQGs [Very Small Quantity Generators] to SQGs [Small Quantity Generators], or from SQGs to LQG [Large Quantity Generators]), resulting in still greater costs.
       EPA has not considered any of these costs. In order to show how great these costs may be, we provide estimates for some of the key costs to the retail sector below. As discussed below, the retail sector alone would likely incur a one-time cost upwards of tens of millions of dollars for making new hazardous waste determinations under the proposed rule. In addition, the change in generator status for some retail facilities would likely result in annual costs of several million dollars per year or ever greater for the industry.
Costs of Reevaluating Wastes Generated by the Retail Sector:   To the extent that EPA issues a final rule that substantively changes the ignitability characteristic (e.g., by establishing an exception to the aqueous alcohol exclusion, narrowing the exclusion in other ways, regulating manufactured articles with minute amounts of liquids, or requiring more aggressive methods to determine if a solid waste contains free liquids for purposes of ignitability  -  or corrosivity  -  testing), generators will have to perform new hazardous waste determinations for all potentially affected wastes. (This might not be necessary to the extent that the final rule merely makes minor technical changes to the ignitability characteristic, such as by clarifying that the aqueous alcohol exclusion applies to wastes with more than 50% water, or by allowing alternative laboratory methods for determining flash point.)
           The retail sector would likely be affected more than any other industry, because of the extremely large number of products that it handles and could potentially generate as wastes. A large retailer with substantial online operations, for example, can be expected to handle over 10 million discrete products, or Shop Keeping Units ("SKUs"). Although many of these items would clearly not be affected by a change to the ignitability characteristic (e.g., apparel and books), the retailer would have to review its entire inventory to identify such items. Moreover, some significant portion of the inventory would require closer scrutiny (e.g., most or all liquid products and/or products that might have even minute amounts of liquid). If we assume that just 10% of the SKUs would require closer scrutiny, that would amount to 1,000,000 new hazardous waste determinations.
            It is difficult to estimate how much each determination would cost, and the cost might vary from item to item (e.g., because some determinations might be relatively simple, while others might require close review of available information from suppliers, requests for supplemental information, expert involvement, and/or laboratory testing). However, in order to obtain a ballpark estimate, we note that EPA in 2015 estimated that the costs of merely recording the results of a single hazardous waste determination to be $12.17. See EPA, "Economic Assessment of the Potential Costs, Benefits, and Other Impacts of the Improvements to the Hazardous Waste Generator Regulatory Program, As Proposed" (June 2015) at 3-7 (stating that "each ... waste determination that a facility must document ... has a cost of $12.17" and clarifying that this reflects only "the costs of documenting and maintaining records" not the costs of actually making the determinations). The cost of making a determination would undoubtedly be much higher, most likely in excess of $100 per SKU. In any event, if we conservatively estimate the cost to be between $12 and $100 per determination, the total cost for a large retailer with substantial online operations (based on 1 million determinations, as estimated above) would be in the range of $12-100 million.
           Of course, only a very small number of retailers have such large product inventories. Based on an informal survey of members of the Retail Associations, chain stores most commonly carry only 10,000 to 50,000 SKUs at a time. Assuming the same 10% of items would require new hazardous waste determinations, and the same cost of $12 to $100 per determination, the cost for a "typical" chain would be between $12,000 and $500,000. We estimate that 200 to 500 chains would experience costs in that range. (The number of stores within such chains would obviously be much higher, but we assume here that the chain would only do the determination once for all of the individual stores that it owns or operates.) Thus, the total costs for new hazardous waste determinations by these chains would be in the range of $2.4 million to $250 million.
           While the numbers above are only estimates, it seems clear that a substantive change to the ignitability characteristic, as the Agency has proposed, would cost the retail sector alone upwards of tens of millions of dollars for reevaluating the materials it handles. The Retail Associations do not believe that such costs can be justified by any potential environmental benefits of the revised characteristic (especially since, as discussed above, it is questionable whether there are any benefits). In any event, it is incumbent on EPA to consider these costs carefully, rather than simply claim that there are no significant costs.
Costs Associated with Changes in Generator Status:  Another potentially significant cost that retailers may incur as a result of the proposed rule is based on the fact that the reclassification of some wastes may cause some retail facilities to have to change their generator status to a higher category of generator (e.g., from VSQG to SQG, or from SQG to LQG). Given the uncertainties discussed above about the scope of EPA's proposal, it is difficult to estimate how many facilities might change status in this way. However, to obtain a ballpark estimate, we note that the Agency has previously estimated that there are 16,774 SQGs and 22,471 VSQGs in the retail sector. See 79 Fed. Reg. 8926, 8932 (February 14, 2014). We believe these numbers are significant underestimates, since they are based on the number of retail facilities in the RCRAInfo database, and there is no reason for most SQGs or VSQGs to be included in that database. This is especially true with respect to VSQGs, given the U.S. Census estimate that there are approximately 1.7 million retail facilities in the U.S. Id. Roughly half of these facilities are in retail sectors (e.g., food service, apparel, and home furnishings) that might not generally be expected to generate hazardous wastes (although they actually might, especially in the course of store maintenance activities). Nevertheless, that still leaves about 800,000 retail facilities that might reasonably be expected to be VSQGs. For current purposes, we will conservatively assume that there are 16,774 retail SQGs (based on EPA's estimate) and between 22,471 and 400,000 retail VSQGs (based, respectively, on EPA's estimate and half of the 800,000 estimate derived above from U.S. Census figures).
           If we assume that only 1% of retail SQGs and VSQGs will change their generator status as a result of the proposal, the numbers would be 167 retailers changing status from SQG to LQG, and between 224 and 4000 retailers changing status from VSQGs to SQGs. EPA has recently estimated that the difference in compliance costs for LQGs and SQGs is $3400 per year, and that the corresponding difference for SQGs and VSQGs is between $3600 and $3800 per year. See, EPA, "Regulatory Impact Analysis of Proposed Rule To Add Aerosol Cans to the Universal Waste Rule" (February 2018) at 25, Table 17. The Retail Associations believe these cost differentials have been understated by EPA. However, if we use those figures, the total increased costs for the retailers changing from SQGs to LQGs would be $578,800 per year (i.e., 167 x $3400), and the total increased costs for the retailers changing from VSQGs to SQGs would be between $806,400 per year (i.e., 224 x $3600) and $15,200,000 per year (i.e., 4000 x $3800). Adding the costs for both categories of generators whose generator status might change, the total would be between $1.4 million and $15.8 million per year.
           Once again, the numbers above are only estimates, but it seems clear that the retail sector could incur costs of several million dollars every year, or even more, as a result of changes in generator status under the proposed rule  -  on top of the one-time cost of tens of millions of dollars to perform new hazardous waste determinations (as discussed above). EPA must take all these costs into account and consider whether they are justified by any potential benefits of the rule. Inasmuch as EPA has not identified any benefits, and we question whether any exist, the Retail Associations do not believe that these costs can in any way be justified. [Commenter 2]
The changes EPA is suggesting identifies "generators and laboratories" as affected parties, 84 FR 12540 col. 3 EPA should be aware that these changes will have substantial implications and burdens on Treatment, Storage and Disposal Facilities (TSDFs). TSDF facilities must perform the ignitibility test methods and apply the regulatory exclusions in order to determine whether hazardous wastes they receive from customers exhibit the ignitibility characteristic. The test methods and procedures are stipulated in their RCRA permits and Waste Analysis Plans (WAPs), which are the result of state permit proceedings with public participation. Changes to the ignitibility test methods will need to be incorporated into the WAPs, which will impose additional costs and burdens on TSDF facilities. Stericycle owns and operates thirteen RCRA Part B permitted TSDFs that are directly and substantially affected by the proposed rule.  [Commenter 10]
Although the proposed rule identifies "generators and laboratories" as affected parties, 84 FR 12540 col. 3, EPA should be aware that commercial treatment, storage and disposal (TSD) facilities probably make more ignitability determinations on hazardous wastes than most other entities. TSD facilities perform the ignitability test methods and apply the regulatory exclusions in order to determine whether hazardous wastes they receive from customers exhibit the ignitability characteristic. The test methods and procedures are stipulated in their RCRA permits and Waste Analysis Plans (WAPs), which are the result of state permit proceedings with public participation. Changes to the ignitability test methods will need to be incorporated into their WAPs, which will impose additional costs and burdens on TSD facilities. As a result, ETC member companies are directly and substantially affected by the proposed rule.  [Commenter 14]
EPA should avoid finalizing prescriptive standards for determining whether free liquid is present in a waste. Currently, industry utilizes multiple tests to determine the presence of liquid, including both the pressure filtration test, and the paint filter test, with many opting for the latter. In addition, such a change could result in the Agency requiring unnecessary testing on a wide variety of wastes that appear solid, and would not normally be subject to testing, to see if any free liquid can be removed by means of pressure filtration.
       Finally, EPA fails to appropriately account for which wastes qualify as a "multiphase mixture." The time it takes for a mixture to separate may vary drastically, and the proposal does not provide clarity as to which methods, and under what timeframe, a waste should be separated. Moreover, the regulated community has long understood that waste analysis under RCRA is supposed to be done at the point of waste generation.  [Commenter 4]

Response to Comments:
Thank you for your comments on potential costs or regulatory impacts of the proposed changes to sampling of multiple phase samples, the aqueous alcohol exclusion, and the application of pressure filtration. The Agency is not finalizing these proposed changes, as discussed in the preamble sections III.D, III.E and III.F. The changes that EPA is finalizing today do not impact how a generator implements the current regulations (e.g., waste analysis plans). Therefore, the Agency does not anticipate the potential costs or impacts discussed by the comments. See the Final Economic Impact Analysis for more discussion of the impacts of the final rule.
Miscellaneous/Other
Comment Excerpts:
In the background information, under section A. What is hazardous waste? I am curious as to why they specifically say that in order for a material to be considered a hazardous waste, the material must be classified as a solid waste first. I don't see why the material has to first be considered a solid waste if hazardous waste can come in liquids and gas. It mentions that solid waste must exhibit any of the four characteristics: ignitability, corrosivity, reactivity, or toxicity. I believe that you could test for these characteristics in a material that was in a liquid waste too. By allowing for hazardous materials to be tested as a liquid waste, the EPA could save time and increase the number of hazardous waste that is being put out into our environment. Testing in solid waste and liquid waste would expand the EPAs list of hazardous waste, which could benefit the environment and would allow the EPA to better regulate hazardous waste.  [Commenter 11]
Response to Comment:
Thank you for your comment. The Agency's defines solid waste under RCRA to include wastes that are liquid, semisolid, and contained gaseous materials (see 42 U.S.C. §6903). The ignitability characteristic applies to liquid wastes in 40 CFR 261.21(a)(1) and will continue to do so under this final rule.
Although not personally impacted by this proposed regulation on labs who test for ignitable hazardous waste, I find this proposed rule to be generally acting in the good of all Americans. On page 66 the rule identifies an ignitable hazardous waste to be any waste that can "cause harm to human health or the environment through direct or indirect fire hazard, including contributing to or causing landfill fires". Thus, by increasing lab safety, environmental compliance and testing validity of what chemicals and waste products are considered ignitable, human health and our environment is being protected as to avoid large landfill fires, forest fires, or other accidental fires.  [Commenter 13]
Response to Comment:
Thank you for your comment. The Agency is updating the ignitability characteristic to improve lab safety and provide flexibility and modernization in testing requirements. See the final rule for more details on what the EPA is finalizing in this rule.

State Authorization:  According to the preamble, EPA will not require states to adopt the proposed rule because the new test methods are neither more, nor less, stringent than current test methods. 84 FR 12550 col. 3. However, while the new flash point test may not be more stringent, clearly narrowing the aqueous alcohol exclusion makes this provision more stringent than the current regulation. Fewer aqueous alcohol waste streams will be excluded, and additional hazardous wastes will be regulated as ignitable, which is obviously more stringent. In addition, EPA's proposal on multiphase wastes, if adopted in whole or in part, over ETC's objections, would impose a more stringent process for handling and testing multiphase wastes by imposing requirements which previously were described in guidance. Likewise, pressure filtration is a more aggressive, costly, and stringent method than the paint filter test for determining free liquids, and therefore is more stringent. The new flashpoint test is only one provision in the proposed rule, and the other provisions regulate more hazardous wastes and impose additional costs and burdens, and therefore are certainly more stringent than current regulations.
       The ETC urges the Agency to carefully address each provision to assess the overall stringency of the final rule and make clear that states are required to adopt the final rule in their state programs due to the more stringent provisions. We believe this approach will ensure consistency and equal stringency in all state programs. Otherwise, this regulation will result in a patchwork of state requirements for ignitability determinations, causing confusion among regulated entities and great expense and harm to the ETC member companies that must conduct their businesses in the national marketplace for hazardous waste management. Patchwork adoption by the states would mean that wastes could be ignitable in some states, but not in other states, where the wastes will be transported, held at transfer facilities, and managed at TSD facilities across the nation. ETC companies need a regulation on ignitability determinations that is consistent in all states in order to rationally conduct the business of hazardous waste recycling, treatment, and disposal.  [Commenter 14]
Response to Comment:
Thank you for your comments. The Agency is not finalizing any provisions that would change the universe of wastes regulated under 40 CFR 261.21, nor change the stringency of current requirements. Specifically, in this final rule, the Agency is retaining the existing test methods, which remain in effect in all states. Authorized states that adopt this rule will also be able to use the new test methods. The Agency expects the existing and newly promulgated test methods to provide equivalent results. Therefore, this rule does not present issues in consistency in authorized state programs.

As an initial matter, USWAG supports EPA's efforts to modernize the RCRA ignitability characteristic by updating the test methods used to make determinations under this characteristic, providing alternatives to the use of mercury thermometers under various test methods and updating cross-references to Department of Transportation regulations.
       We are also supportive of the incorporation of long-standing guidance into to RCRA regulations assuming EPA's positions reflected in the guidance have been fully consistent and have already been incorporated into the regulated public's understanding of the RCRA provisions. While we have no specific reason to believe that the Agency's positions reflected in the guidance being incorporated has been inconsistent or not well-understood by the regulated public, we would object to the codification of guidance that other commenters maintain has been inconsistent or unclear.  [Commenter 15]
Response to Comments:
Thank you for your comments. At this time, the Agency is only codifying the guidance that defines aqueous as "at least 50 percent water by weight." This change is supported by commenters. See section 6 above and section III.D in the final rule for more information.

       Modernizing Ignitable Liquids Determinations Rule - Commenter Key

 American Fuel & Petrochemical Manufacturers
 Retail Industry Leaders Association and National Association of Chain Drug Stores
 Anonymous; Tracking No. 1k3-9a9x-4fr7; Received June 3, 2019
 American Chemistry Council
 American Council of Independent Laboratories
 American Petroleum Institute
 Maryland Department of the Environment
 ConocoPhillips Alaska, Inc.
 Coalition for Responsible Waste Incineration
 Stericycle, Inc.
 Anonymous; Tracking No. 1k3-9a9a-2cog; Received June 2, 2019
 Anonymous; dated April 24, 2019
 Anonymous; Tracking No. 1k3-99cu -b5ea; Received: April 15, 2019
 Environmental Technology Council
 Utility Solid Waste Activities Group