EPA Positions on Contained Gas 

II. EPA has had a consistent position on the meaning of "contained gaseous 

material" since 1982. 

The RCRA definition ofsolid wastes states: 

The tenn 'solid waste' means any garbage, refuse, sludge from a waste treatment 

plant, water supply treatment plant, or air pollution control facility and other 

discarded material, including solid, liquid, semisolid, or contained gaseous 

material resulting from industrial, commercial, mining, and agricultural 

operations, and from community activities ...." 42 U.S.C. 6904(27). 

Under this definition, a gas must be contained before it can be considered a solid waste. 

EPA has never considered gas in a pipeline to be "contained" under this definition. 

This position was established 1982, in EPA's regulations for hazardous waste 

incineration facilities. 47 Fed. Reg. 27520 (June 24, 1982). In this final rule, EPA was 

presented with the question whether RCRA regulations apply to fume incinerators 

installed as air pollution control devices. EPA stated: 

EPA agrees with commenters that fume incinerators are subject only to 

regulation under the Clean Air Act and does not intend that Parts 264 and 

265 regulations apply to these facilities. Fume incinerators which are used 

to destroy gaseous emissions from various industrial processes, for 

example, are not subject to regulation under RCRA. In general the RCRA 

standards do not apply to fume incinerators since the input is not 

identifiable as solid waste, according to the definition set forth in § 261.2. 

47 Fed. Reg. at 27530. 

EPA reaffirmed this interpretation of RCRA in 1986. In response to a question posed 

to the RCRA Hotline, EPA stated "a fume incinerator used only to destroy gaseous 

emissions from an industrial process is not subject to RCRA regulation since the fume 

input, being an uncontained gas, is not a solid waste (per the June 24, 1982, Federal 

Register (47 FR 27530))." RCRAISuperfund Hotline Monthly Summary, 9488.1986(03), 

available at RCRA Online. 

EPA reaffirmed this interpretation again in 1987. In response to a question regarding 

a methanol recovery process, EPA distinguished between gases and condensate. 

1. Stream A, the methanol-laden air from the drying and granulation step 

ofthe process, does not meet the definition ofsolid waste under RCRA 

because it is in vapor form and not confined in a container. 
2. The carbon beds that both condense and adsorb the methanol from the 

air contains an F003 waste when the condensation of the methanol occurs. 

Therefore, stream B, the carbon/methanol mixture is to be handled as a 

listed hazardous waste. 

Memorandum from Matthew Straus, Chief: Waste Characterization Branch, to Clifford 

Ng, Engineer, EPA Region II, dated June 17, 1987, available at RCRA Online. 

EPA reaffirmed this interpretation again in 1989, in a final rule listing certain waste 

generated from the manufacture of chlorinated aliphatic hydrocarbons. In the proposed 

rule, EPA had proposed regulating gases that wcre capable of being condensed as solid 

waste (and therefore hazardous wastes) even if they were not in a condensed fonn. In the 

final rule, EPA changed its mind: 

Upon reconsideration of this issue (with the benefit of comments received 

on the proposed rulemaking). EPA now believes our authority to identify 

or list a waste as hazardous under RCRA is limited to containerized or 

condensed gases (i.e., section 1004(27) ofReRA excludes all other gases 

from the definition ofsolid wastes and thus cannot be considered 

hazardous wastes}. 

54 Fed. Reg. 50968, 50973; see also id. at note 5 ("EPA's previously issued guidance 

concerned fume incinerators (contained in the preamble to the incineration regulations) 

remains in effect. See 47 FR 27530, June 24, 1982. Fume incinerators are installed as air 

pollution control devices pursuant to regulations under the Clean Air Act; they re used to 

destroy gaseous emissions fonn various industrial processes. EPA concluded that, in 

general, RCRA standards do not apply to fume incinerators because the input (an 

uncontainerized gas) is not a solid waste according to the definition set forth in §261.2."). 

EPA reaffirmed this interpretation again in 1990. In the Hazardous Waste TSDF ­

Technical Guidance RCRA Air Emission Standards for Process Vents and Equipment 

Leaks, EPA-450/3-89-021 (July 1990) at page 2-3 EPA states: "Air standards have been 

promulgated for the control of air emissions from pennitted hazardous waste incinerators. 

40 CFR Part 264, Subpart o. These standards require that incinerators burning hazardous 

waste be operated to achieve a destruction and removal efficiency (DRE) of at least 99.99 

percent for those primary organic hazardous constituents listed in the facility pennit 

However, the process vent stream (i.e. gases and vapors) from a hazardous waste 

management unit would not be classified as a hazardous wastes. Noncontainerized gases 

emitted from hazardous wastes are not themselves hazardous wastes because the RCRA 

statute implicitly excludes them. Therefore combustion ofprocess vent streams in an 

incinerator is not subject to the 99.99 DRE requirement." 

EPA reaffirmed this interpretation again in 1991, in a rule addressing the burning of 

hazardous wastes in boilers and industrial furnaces. In response to comments requesting 

that EPA revise the definition of carbon regeneration unit so that units used for air 

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emissions control, wet oxidation, and general recycling would not be regulated, EPA 

stated: 

Activated carbon units used as air emissions control devices of gaseous 

industrial process emissions will not necessarily be regulated because 

trapped organics in such columns are not hazardous wastes because the 

gas originally being treated is not a solid waste (it is an uncontained gas), 

and therefore any condensed organics do not derive from the treatment of 

a hazardous waste. 

56 Fed. Reg. 7134, 7200 (Feb. 21, 1991) (citations omitted). 

EPA reaffirmed this interpretation again in 1994. See the Hazardous Waste 

Treatment, Storage, and Disposal Facilities (TSDF): Background Infonnation for 

Promulgated Organic Air Organic Air Emission Standards for Tanks, Surface 

Impoundments, and Containers, EPAl453/R-94/076b (November 1994) (since organic 

vapors emitted from hazardous waste are not solid or hazardous waste, control devices 

installed to comply with Subpart CC organic vapor control requirements are not 

hazardous waste management units and do not require RCRA pennits). 

EPA reaffirmed this interpretation in the 2000 CISWI Rule. EPA included the 

following language on air pollution control devices in its response to comments: 

Control Devices 

Comment: Three commenters (IV-D-09, IV-D-25, IV-D-49) stated that air pollution 

control equipment should be categorically exempt from the CISWI standards and guidelines. 

One commenter (IV -D-35) stated that any combustion device whose function is pollution control 

as mandated by another Federal or State requirement should be exempt from the CISWI 

standards and guidelines. One commenter (IV -D-73) stated that the CISWI standards and 

guidelines are not clear as to whether they apply to flares burning surplus, by-product, blast 

furnace gas. One commenter (IV-D-94) stated that it is unclear whether incinerators used for air 

pollution control are covered by the CISWI standards and guidelines. 

Response: Incinerators used as air pollution control devices and flares would not be 

covered by the CIS WI standards and guidelines because they are not burning contained gases. 

The definition of solid waste includes only " ... solid. liquid, semisolid, or contained gaseous 

materials..." Adefinition of "contained gaseous material" has been added to the CISWI 

standards and guidelines to clarify that only gases that are in a container when that container is 

combusted are covered by the CISWI standards and guidelines. 

2000 CISWI Rule Response to Comments, at 15. 

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Finally, EPA's long-standing interpretation has been upheld by the Administrator 

and the Environmental Appeals Board. See, e.g. In re BP Chemicals America, Inc., 

RCRA Appeal No. 89-4, 1991 EPA App. LEXIS 27; 3 E.A.D. 667 (Admin., Aug. 20, 

1991) (The Administrator specifically rejected Region V's argument that gaseous 

emissions were "contained" by the process units they passed through, associated piping 

or the facility itself, holding that the Agency's definition of the term "contained" has 

consistently been confined "in the narrower sense of being in an individual container such 

that the gas is amenable to shipment"). See also Environmental Appeals Board In re: 

Chemical Waste Management a/Indiana, Inc., RCRA Appeal No. 95-4, 1995 EPA App. 

LEXIS 31 (EAB, Aug. 23, 1995) (emissions from microencapsulation ofhazardous 

debris) (The EAB concludes the air emissions are excludable from Subtitle C regulation 

"because the air emissions that the Region seeks to regulate are not containerized.") 

II. Consequences if EPA changes its interpretation. 

If EPA changes its interpretation ofthe term "contained gaseous material," flares and 

other air pollution control equipment could now be considered solid waste incinerators 

subject to CISWI standards. The same would be true of units that combust gaseous fuels 

derived from secondary material. Virtually every sector of U.S. manufacturing, as well 

as the waste and wastewater management sectors, will be thrown into disarray. 

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