On April 2, 2019, the United States Environmental Protection Agency (EPA) published its proposed “Modernizing Ignitable Liquids Determinations” rule in the Federal Register.[1]  Ostensibly, the rule is, as described in its title, an effort to “modernize” – i.e., update – certain aspects of the regulations relating to determining whether a waste is a hazardous waste based on the characteristic of ignitability, which are found in 40 C.F.R. 261.21. 

For instance, one of the proposed rule changes pertains to updating the flash point test methods, SW–846 Method 1010A and 1020B, which are over 40 years old.  SW–846 Method 1010A currently incorporates by reference ASTM standards D 93–79 and D 93–80, which together are known as the Pensky-Martens method, and Method 1020B currently incorporates by reference ASTM standard D 3278–78, otherwise known as the Setaflash method.  EPA is proposing to revise the ignitability rule so as to update Method 1010A to Method 1010B to incorporate by reference ASTM standard D 8175–18 as an alternative to the Pensky-Martens method; and to update Method 1020B to Method 1020C, incorporating by reference the resulting ASTM standard D 8174–18 as an alternative to the Setaflash method.   EPA proposes to leave the old standards in the rule to provide the regulated community an opportunity to transition between the old and new standards. However, EPA indicated in the proposed rule that it may remove the old standards in a future update.

EPA is also proposing to allow alternatives to mercury thermometers used in the air sampling and stack emissions methods in SW–846, which currently require the use of mercury thermometers.  EPA's goal is to eliminate the requirement to use mercury thermometers.  Similarly, EPA proposes to allow users to continue utilizing mercury thermometers, but they will have the option of using alternative temperature-measuring devices instead.

Next, the proposed rule includes the codification of existing guidance in two areas.  The first area pertains to the regulatory exclusion in the ignitable characteristic for aqueous liquids containing alcohols.  Under the proposed rule, the term “aqueous” (which is currently undefined in the RCRA hazardous waste regulations) would be removed from the exclusion and language would be added specifying that the solution must be least 50 percent water by weight. 

In this regard, EPA is requesting input from waste generators, laboratories, and other members of the public who may have information regarding the specific hazards, or lack thereof, of managing waste streams pursuant to the current exclusion and comments on whether additional changes to the exclusion may be warranted, such as (1) “explicitly identifying specific waste streams in the regulation to which the exclusion would apply to remove the uncertainty regarding the current scope of the exclusion;” (2) “narrowing the types of alcohol that would qualify for the aqueous alcohol exclusion;” and (3) “adding a minimum alcohol content as a requirement for excluded wastes to better target potential waste streams that flash primarily from their alcoholic components or adding to or improving the existing criteria a waste must meet to be eligible for the exclusion (e.g., raise the minimum water content for aqueous alcohol solutions) to decrease the likelihood that a liquid waste excluded from the ignitability characteristic would be able to sustain combustion or otherwise contribute to an ongoing fire.”

The second area of existing guidance which EPA is proposing to codify pertains to sampling of waste mixtures having multiple phases when determining whether a waste exhibits the ignitability characteristic.  SWF-846 provides that multiphase mixtures should be separated so each phase is analyzed individually: “Attempts should be made to break up and separate the phases of an emulsion. . . . If the emulsion can be broken, the different phases (aqueous, solid, or organic liquid) may then be analyzed separately.”  EPA would add language that specifies how to test multiphase wastes containing multiple liquid(s) with or without solids for ignitability determinations by making EPA’s existing sampling procedures for multiphase samples applicable to all liquid wastes tested under the ignitability rule.

Lastly, EPA is proposing to update various cross-references to Department of Transportation regulations and to remove obsolete information.

The comment period for this proposed rule closed on June 3, 2019. A total of 11 comments were submitted.  The final rule is anticipated to be promulgated in February 2020.