United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued May 7, 2010 Decided August 6, 2010 

No. 09-5360 

HOWMET CORPORATION, 

APPELLANT

v. 

ENVIRONMENTAL PROTECTION AGENCY AND LISA PEREZ 

JACKSON, ADMINISTRATOR, UNITED STATES ENVIRONMENTAL 

PROTECTION AGENCY, 

APPELLEES

Appeal from the United States District Court 

for the District of Columbia 

(No. 1:07-cv-01306-EGS) 

Bryan J. Moore argued the cause and filed the briefs for 

appellant. 

Donald J. Patterson, Jr. and Bethany S. French were on 

the brief for amicus curiae Alliance of Automobile 

Manufacturers in support of appellant. 
2 

Justin R. Pidot, Attorney, U.S. Department of Justice, 

argued the cause for appellees. With him on the brief was 

Robert H. Oakley, Attorney. 

Before: SENTELLE, Chief Judge, BROWN and 

KAVANAUGH, Circuit Judges. 

Opinion for the Court filed by Circuit Judge BROWN. 

Dissenting opinion filed by Circuit Judge KAVANAUGH. 

 

BROWN, Circuit Judge: The Environmental Protection 

Agency (EPA or the Agency) says Howmet Corporation 

(Howmet) violated the Resource Conservation and Recovery 

Act and the Hazardous and Solid Waste Amendments of 1984, 

42 U.S.C. §§ 6901 et seq. (collectively RCRA), and its 

implementing regulations. Howmet says its actions were 

permitted by the regulations. Whether viewed as a syntactical 

ambiguity or a semantic squabble, the dispute focuses on one 

question: when is a material no longer serving “the purpose 

for which it was produced?” The EPA insists the initial use of 

the material is determinative; Howmet contends the initial use 

is irrelevant. The question matters because “spent material” is 

subject to RCRA’s hazardous waste regulations, but material 

that has not been spent is not. Howmet insisted that used 

KOH (liquid potassium hydroxide) sent to a fertilizer 

manufacturer for use as a fertilizer ingredient was not “spent 

material” and thus not subject to RCRA regulations. After 

Howmet lost this argument before an administrative law judge 

(ALJ) and the Environmental Appeals Board (EAB), the 

district court rejected Howmet’s Administrative Procedure 

Act claim and granted the EPA’s cross-motion for summary 

judgment, holding the EPA’s interpretation of its “spent 

material” regulation was not arbitrary and capricious and that 

Howmet had fair notice of the Agency’s interpretation. See 
3 

Howmet Corp. v. EPA, 656 F. Supp. 2d 167 (D.D.C. 2009). 

We affirm. 

I 

Subtitle C of RCRA, 42 U.S.C. §§ 6921–34, establishes a 

“stringent ‘cradle-to-grave’ regulatory structure for overseeing 

the safe treatment, storage and disposal of hazardous waste.” 

Sierra Club v. EPA, 292 F.3d 895, 896 (D.C. Cir. 2001). The 

statute defines “hazardous waste” as a “solid waste [that] may 

. . . pose a substantial present or potential hazard to human 

health or the environment when improperly treated, stored, 

transported, or disposed of, or otherwise managed.” 42 

U.S.C. § 6903(5). The EPA has broad investigatory and 

enforcement authority under RCRA. See Gen. Motors Corp. 

v. EPA, 363 F.3d 442, 444 (D.C. Cir. 2004). Pursuant to this 

authority, the EPA has imposed numerous requirements and 

restrictions on the generators and transporters of hazardous 

waste, including requiring EPA identification numbers, 40 

C.F.R. § 262.12(c), the use of hazardous waste manifests 

identifying contaminants, id. § 262.20(a), and written 

notification of land disposal restrictions, id. § 268.7(a). 

Hazardous wastes are a subset of solid wastes. See 42 

U.S.C. § 6903(5); 40 C.F.R. § 261.3(a). Since a substance 

cannot be a “hazardous waste” or subject to the EPA’s 

hazardous waste regulations unless it satisfies the threshold 

definition of “solid waste,” our analysis begins with the 

definition of solid waste. “Solid waste” is “discarded 

material, including solid, liquid, semisolid, or contained 

gaseous material resulting from industrial, commercial, 

mining, and agricultural operations.” 42 U.S.C. § 6903(27). 

Discarded material includes recycled materials (materials that 

have been “used, reused, or reclaimed,” 40 C.F.R. 

§ 261.1(c)(7)) and spent materials (any material so 
4 

contaminated by use it can no longer serve “the purpose for 

which it was produced without processing,” id. § 261.1(c)(1)). 

Under the EPA’s regulations, when a spent material is 

recycled, it must be managed as a solid waste. Moreover, if 

the material also exhibits a hazardous characteristic, such as 

corrosivity,1 see id. §§ 261.3(a), 261.20–.24, it must be 

managed as a hazardous waste subject to the RCRA 

requirements. Thus, as the EAB noted, when a hazardous 

“spent material” is recycled, or “[u]sed to produce products 

that are applied to or placed on the land or are otherwise 

contained in products that are applied to or placed on the 

land,” id. § 261.2(c)(1)(i)(B), it must be managed as 

hazardous waste. The resolution of this appeal rests on 

whether the materials in question were “spent” and should be 

deemed solid waste. Since “spent material” is material that 

has been used and as a result of contamination can no longer 

serve “the purpose for which it was produced without 

processing,” the central issue in this case is the interpretation 

of the phrase “the purpose for which it was produced.” 

The EAB’s syllabus succinctly summarizes the dueling 

interpretations: “Howmet argues that ‘purpose’ implies a 

fundamental purpose. Howmet’s interpretation would allow a 

multi-use product, such as KOH, to be used first as a cleaning 

agent and then as a fertilizer ingredient without being ‘spent,’ 

because both uses allegedly are consistent with KOH’s broad 

fundamental purpose as a concentrated source of hydroxide 

ions and of potassium. [The Agency argues] that a product’s 

purpose for production (i.e., ‘the purpose for which it was 

produced’) must be related to its original use, [so] a product 

first used as a cleaning agent becomes a ‘spent material’ when 

 

1

 Corrosivity is deemed present if the waste is aqueous and has a pH 

of less than or equal to 2 or greater than or equal to 12.5. See 40 

C.F.R. § 261.22(a). 
5 

it becomes too contaminated for that use and then is sent to a 

fertilizer manufacturer to be used in a fundamentally different 

manner.” 

II 

 The facts in this case are not in dispute. Howmet 

manufactures precision investment castings for aerospace and 

industrial gas turbine applications. To clean the ceramic core 

from the metal castings, Howmet uses an aqueous KOH 

solution. During the cleaning process the KOH is 

contaminated. Howmet uses the KOH solution until it 

becomes so contaminated it can no longer effectively clean 

the castings. The used KOH is corrosive. Thus, under the 

EPA’s regulations, the used KOH would be regulated as 

hazardous waste. See 40 C.F.R. § 261.22. 

Typically, Howmet accumulates the used KOH in storage 

tanks at an authorized hazardous waste disposal facility. 

However, between August 1999 and September 2000, 

Howmet sent some of the used KOH to Royster, an 

independent fertilizer manufacturing company that, without 

processing or otherwise reclaiming it, added the KOH to its 

fertilizer to control pH and provide a source of potassium. 

Howmet did not prepare any hazardous waste manifest for the 

shipments to Royster or otherwise treat the KOH as a 

hazardous waste under RCRA, 42 U.S.C. §§ 6901–91. 

 In 2003, the EPA brought enforcement actions against 

Howmet, alleging the used KOH sent to Royster was a solid 

and characteristic hazardous waste, in that it was corrosive 

and potentially contaminated with chromium, and therefore 

subject to RCRA jurisdiction. The EPA alleged Howmet 

violated RCRA and its implementing regulations by 

(1) shipping hazardous waste to facilities that did not have an 
6 

EPA identification number; (2) sending hazardous waste 

offsite using transporters without EPA identification numbers; 

(3) failing to prepare hazardous waste manifests for the KOH 

shipments to Royster; and (4) failing to send and maintain on 

file appropriate land disposal restriction notifications for the 

KOH shipments informing Royster whether the KOH was too 

contaminated for land application without prior treatment. 

Howmet contested the allegations and requested a 

hearing. An ALJ found Howmet liable under RCRA, 

concluding the used KOH sent to Royster was a hazardous 

“spent material” and therefore a solid waste that must be 

managed as a hazardous waste and that Howmet had failed to 

manage the KOH in accordance with EPA regulations. The 

ALJ also concluded Howmet had not proved it was denied due 

process because it had not received fair notice of the EPA’s 

interpretation of its spent material regulation. The ALJ 

assessed a civil fine of $309,091 against Howmet. Howmet 

appealed to the EAB, which upheld the ALJ’s finding in a 

lengthy decision detailing RCRA’s statutory and regulatory 

framework. Howmet filed a complaint in the district court 

claiming the EAB’s decision was arbitrary and capricious, but 

the district court awarded summary judgment in favor of the 

EPA, holding the EPA reasonably interpreted its “spent 

material” regulation and that Howmet had fair notice of the 

EPA’s interpretation. Howmet Corp., 656 F. Supp. 2d 167. 

This appeal followed. 

III 

We review the district court’s grant of summary judgment 

de novo, see Steele v. Schafer, 535 F.3d 689, 692 (D.C. Cir. 

2008), and must set aside the EPA’s final determination if 

“arbitrary, capricious, an abuse of discretion, or otherwise not 

in accordance with law,” 5 U.S.C. § 706(2)(A). We accord an 
7 

agency’s interpretation of its own regulations a “high level of 

deference,” accepting it “unless it is plainly wrong.” Gen. 

Elec. Co. v. EPA, 53 F.3d 1324, 1327 (D.C. Cir. 1995); see 

also Exportal Ltda. v. United States, 902 F.2d 45, 50 (D.C. 

Cir. 1990) (“It is well established that a reviewing court owes 

deference to an agency’s construction of its own 

regulations.”). Under this standard, we must defer to the 

EPA’s interpretation as long as it is “logically consistent with 

the language of the regulation[s] and . . . serves a permissible 

regulatory function.” Gen. Elec., 53 F.3d at 1327. But see 

Exportal, 902 F.2d at 50 (explaining deference is due “only

when the plain meaning of the rule itself is doubtful or 

ambiguous” and thus deference to an agency’s interpretation 

“is not in order if the rule’s meaning is clear on its face”). 

Moreover, “[t]he policy favoring deference is particularly 

important where . . . a technically complex statutory scheme is 

backed by an even more complex and comprehensive set of 

regulations.” Gen. Elec., 53 F.3d at 1327 (noting that “[i]n 

such circumstances, ‘the arguments for deference to 

administrative expertise are at their strongest’”). 

 A. The definition of “spent material” is ambiguous 

Both parties seem to agree our analysis should begin with 

determining whether the regulatory text of the EPA’s spent 

material definition, as applied to Howmet’s KOH shipments 

to Royster, is clear on its face. Howmet argues the EPA’s 

definition is unambiguous. It claims both the dictionary 

definition of “purpose” (“the object . . . for which something 

exists”), as well as the context of the regulation, are relevant 

and support its position. Howmet insists the plain language of 

the definition—“the purpose for which it was produced”—

looks retrospectively to a material’s intended purpose at the 

time it was produced, not prospectively to the first use made 

of the material following its production and therefore does not 
8 

permit the interpretation adopted by the EPA. The EPA, on 

the other hand, argues the word “purpose” is ambiguous, both 

taken alone and in context, and that the phrase “the purpose 

for which it was produced” could relate to a material’s use, 

especially where, as here, the producer of the material does 

not itself put the material to use, but rather creates the product 

for sale. We agree with the EPA. 

 Neither the word “purpose” nor the phrase “the purpose 

for which it was produced” are defined in the EPA’s 

regulations, and the dictionary definition relied on by Howmet 

provides little help in determining the meaning of either the 

word or phrase, as they are used in 40 C.F.R. § 261.1. The 

everyday meanings of the term and phrase also do not provide 

any clarity as to whether the initial use of a material is 

relevant to determining the purpose for which the material 

was produced. In sum, the text of the EPA’s definition is 

simply ambiguous with respect to whether we should adopt 

Howmet’s “multiple, original purposes” approach to 

determining when a material is “spent,” or whether we should, 

instead, adopt the “original use”-based purpose test advanced 

by the EPA. 

B. The EPA’s interpretation of the “spent material” 

 regulation is reasonable 

Having concluded the plain language of the EPA’s “spent 

material” definition does not answer the question whether the 

used KOH sent to Royster was a spent material, we examine 

whether the EPA’s interpretation of the definition is 

reasonable. See, e.g., Gorman v. NTSB, 558 F.3d 580, 589 

(D.C. Cir. 2009) (explaining this court must uphold an 

agency’s interpretation of an ambiguous regulation if 

reasonable); Devon Energy Corp. v. Kempthorne, 551 F.3d 

1030, 1037 (D.C. Cir. 2008). In so doing, we look to the 
9 

EPA’s overall regulatory framework under RCRA, as well as 

the regulatory history of the Agency’s “spent material” 

definition. Both establish the EPA’s interpretation is 

reasonable and consistent with the Agency’s prior 

interpretations. 

1. Regulatory History of the EPA’s “Spent Material” 

Definition 

The EPA’s current hazardous waste regulations were 

promulgated in 1985 primarily to clarify “which materials are 

solid and hazardous wastes when they are recycled.” 

Hazardous Waste Mgmt. Sys.; Definition of Solid Waste, 50 

Fed. Reg. 614, 614 (Jan. 4, 1985) (to be codified at 40 C.F.R. 

pts. 260, 261, 264, 265, 266). The EPA’s original 1980 

regulations implementing Subtitle C of RCRA did not include 

a reference to “spent material” or a material’s “purpose.” 

Hazardous Waste Mgmt. Sys.: Identification and Listing of 

Hazardous Waste, 45 Fed. Reg. 33,084 (May 19, 1980) (to be 

codified at 40 C.F.R. pt. 261). Instead, a material was 

considered “solid waste” when, among other things, it had 

been “used” and “sometimes discarded.” See id. at 33,093, 

33,119. Under the regulations, a material that “ha[d] served 

its original intended use and sometimes [wa]s discarded” was 

a “solid waste.” 40 C.F.R. § 261.2(b)(2) (1980) (emphasis 

added); see also 45 Fed. Reg. at 33,119.2

 Thus, once a 

material had been used and could no longer serve its originally 

intended use, it was considered waste. Notably, the preamble 

to the final 1980 regulations used the phrase “original 

intended purpose” rather than “original intended use” to 

 

2

 A material was “discarded” if, among other things, it was “placed 

into or on any land” without being “re-used, reclaimed or recycled.” 

40 C.F.R. § 261.2(c), (d) (1980); see also 45 Fed. Reg. at 33,119. 
10 

describe “solid waste.” 45 Fed. Reg. at 33,093, 33,099 

(emphasis added). The preamble, while not binding, see 

Kennecott Utah Copper Corp. v. U.S. Dep’t of the Interior, 88 

F.3d 1191, 1223 (D.C. Cir. 1996) (explaining “whether [a] 

preamble has independent legal effect . . . is a function of the 

agency’s intention to bind either itself or regulated parties); 

see also Nat’l Res. Def. Council v. EPA, 559 F.3d 561, 565 

(D.C. Cir. 2009), is informative with respect to how the EPA 

intended to determine a material’s “purpose.” The fact the 

EPA substituted the term “use” for “purpose” in the final 

regulation is consistent with the EPA’s current position that a 

used material’s original “purpose” should be determined by 

looking to how the material was initially deployed after being 

purchased as a product—i.e., the material’s “original intended 

use.” 

 In 1983, the EPA proposed the rule containing the current 

hazardous waste regulations. See Hazardous Waste Mgmt. 

Sys., 48 Fed. Reg. 14,472 (proposed Apr. 4, 1983) (to be 

codified at 40 C.F.R. pts. 260, 261, 264, 265, 266). The 

Agency proposed several important changes to the definition 

of “solid waste.” Most importantly, the EPA’s proposed 

definition would no longer base a material’s status as solid 

waste on whether it was “sometimes discarded.” See id. at 

14,475. Instead, a recycled material’s regulatory status would 

depend “upon both what the material [was] and how it [was] 

actually managed.” Id. The revised definition of “solid 

waste” stated that five types of recycling activities, including 

“[u]se constituting disposal . . . which involves the direct 

placement of wastes onto the land,” would be within the 

EPA’s jurisdiction. Id. at 14,476. The five categories were 

further divided according to the type of waste involved. One 

such type of waste was “spent material,” which the EPA 

described in the preamble as “materials that have been used 

and are no longer fit for use without being regenerated, 
11 

reclaimed, or otherwise re-processed.” Id. (emphasis added). 

The EPA explained that “processes using spent materials may 

be more logical candidates for regulation because spent 

materials (having already fulfilled their original use) are more 

inherently waste-like.” Id. at 14,488 (emphasis added). The 

proposed regulation itself defined “spent material” as “any 

material that has been used and has served its original 

purpose.” Id. at 14,508 (proposed 40 C.F.R. § 261.2(b)(1)) 

(emphasis added). Again, the EPA’s synonymous use of the 

singular term “original use” and the term “original purpose” 

reveals the Agency viewed the two concepts as closely 

connected and interrelated. 

The EPA finalized the proposed regulations in 1985. See 

Hazardous Waste Mgmt. Sys.; Definition of Solid Waste, 50 

Fed. Reg. 614 (Jan. 4, 1985). Although the EPA stated it 

“was continuing to define spent materials as those which have 

been used and are no longer fit for use without being 

regenerated, reclaimed, or otherwise reprocessed,” id. at 624, 

the EPA acknowledged its “reference to original purpose [in 

the 1983 proposed regulations] was ambiguous when applied 

to situations where a material can be used further without 

being reclaimed, but the further use is not identical to the 

initial use.” Id. The Agency therefore stated it was 

“clarifying what [it] mean[t] by spent materials,” id., and, 

accordingly, revised the wording of the definition to read as it 

does today: “A ‘spent material’ is any material that has been 

used and as a result of contamination can no longer serve the 

purpose for which it was produced without processing,” 40 

C.F.R. § 261.1(c)(1) (1985). In the preamble, the EPA 

provided an example of a product used for a subsequent 

purpose not identical to its original use that would not be 

considered a spent material: 
12 

[W]here solvents used to clean circuit boards are no[] 

longer pure enough for that continued use, but are still 

pure enough for use as metal degreasers. These 

solvents are not spent materials when used for metal 

degreasing. The practice is simply continued use of a 

solvent (This is analogous to using/reusing a 

secondary material as an effective substitute for 

commercial products.). The reworded regulation 

clarifies this by stating that spent materials are those 

that have been used, and as a result of that use become 

contaminated by physical or chemical impurities, and 

can no longer serve the purpose for which they were 

produced. 

50 Fed. Reg. at 624. 

As noted above, we recognize an agency’s preamble 

guidance generally does not have the binding force of the 

agency’s regulations. Nonetheless, it is at least informative. 

The example the EPA provided is illustrative of the type of 

subsequent use of a material it sought to regulate under 

RCRA. The example suggested certain “continued use[s]” of 

a material sufficiently similar to or consistent with the 

material’s initial use would be considered “a purpose for 

which [the material] was produced” and thus permitted under 

the Agency’s “spent material” definition. Thus, the example 

makes clear the EPA was, in both 1983 and 1985, associating 

the concept of “purpose” with “initial use.” The EPA’s 

accompanying explanation further indicates the Agency 

intended to place limits on the types of reuse allowable under 

its regulations. The Agency’s acknowledgement that its spent 

material definition was ambiguous when applied to situations 

where a material’s “further use is not identical to [its] initial 

use” implies the Agency intended to create a distinction 
13 

between certain types of reuse.3

 In fact, had the EPA 

intended, as Howmet insists, to allow any reuse that is a 

“normal use” of a material, its clarification of situations where 

“the further use is not identical to the initial use” would have 

been superfluous. 

2. RCRA’s overall purpose 

In addition to being inconsistent with the regulatory 

history of the EPA’s “spent material” definition, we find 

Howmet’s position to be incompatible with the overall thrust 

of RCRA and its implementing regulations. Congress 

described the national policy objective of RCRA as, wherever 

feasible, reducing or eliminating “the generation of hazardous 

waste.” 42 U.S.C. § 6902(b). “Waste that is nevertheless 

generated should be treated, stored, or disposed of so as to 

minimize the present and future threat to human health and the 

environment.” Id. Congress recognized that “disposal of 

solid waste and hazardous waste in or on the land without 

careful planning and management can present a danger to 

 

3

 Amicus Curiae in support of Howmet, Alliance of Automobile 

Manufacturers, argues that, under the EAB’s decision in In Re: Gen. 

Motors Auto.-N. Am., No. RCRA 05-2004-0001, Appeal No. RCRA 

(3008) 06-02 (EAB June 20, 2008), handed down a year after the 

EAB’s decision in Howmet, a material is not “spent” if 

subsequently used for a “legitimate purpose,” even if that use is 

different “in some sense” from how it was used in its initial 

deployment. Amicus Br. at 5–7. However, Amicus’ argument 

ignores a key part of the EAB’s holding in General Motors. In 

General Motors, the EAB clarified its “continued use” policy by 

holding a subsequent use must satisfy two primary conditions in 

order to be considered “a purpose for which [the material] was 

produced.” In re: Gen. Motors, slip op. at 2. The first condition is 

that the continued use “must be similar to or consistent with the 

initial deployment or application of the material.” Id. 
14 

human health and the environment.” Id. § 6901(b)(2). 

Moreover, Congress acknowledged that materials being 

reused and recycled “can indeed be solid and hazardous 

wastes and that these various recycling activities may 

constitute hazardous waste treatment, storage, or disposal.” 

H.R. REP. NO. 98-198(I), at 46 (1983), reprinted in 1984 

U.S.C.C.A.N. 5576, 5605. Congress thus conceded that 

certain recycled materials must be regulated in order to further 

its overall goal of “protect[ing] human health and the 

environment.” Id. 

Consistent with Congress’s guidance, the EPA’s 

regulations recognize that recyclable materials, if not managed 

properly, may present significant risks to public health and the 

environment. Congress and the EPA have also indicated their 

concerns are heightened when materials and applications 

applied to the land are involved. See 48 Fed. Reg. at 14,474 

(explaining that “wastes destined for recycling can present the 

same potential for harm as wastes destined for treatment and 

disposal,” that “using or reusing wastes by placing them 

directly on the land . . . may present the same sorts of hazards 

as actually incinerating or disposing of them,” and noting 

“[f]acilities that recycle hazardous wastes have caused serious 

health and environmental problems by directly placing the 

wastes on the land” and that “[i]mproper storage, 

overaccumulation of inventory, and unsafe transport before 

recycling have also been recurring problems”). 

Under the EPA’s regulations, certain recycled materials 

are not treated as solid wastes when “[u]sed or reused as 

ingredients in an industrial process to make a product, 

provided the materials are not being reclaimed” or “[u]sed or 

reused as effective substitutes for commercial products.” 40 

C.F.R. § 261.2(e)(1)(i), (ii). However, “[m]aterials used in a 

manner constituting disposal, or used to produce products that 
15 

are applied to the land,” id. § 261.2(e)(2)(i), are treated as 

solid wastes, regardless, “even if the recycling involves use, 

reuse, or return to the original process,” id. § 261.2(e)(2). 

Accordingly, when a material has become contaminated, and a 

party seeks to use the contaminated material for a purpose 

substantially different from its original use by applying it to 

the land, the party seeking to reuse the material has an 

obligation to examine the material, disclose its hazardous 

characteristics, and treat it as a hazardous waste. Fertilizer is 

indisputably a product “applied to the land.” Thus, the 

shipment of a corrosive material such as used KOH to be used 

to produce fertilizer appears to be the type of activity the EPA 

sought to regulate under RCRA. 

Having determined the Agency’s interpretation is 

reasonable, we need not evaluate the reasonableness of 

Howmet’s proposed interpretation. Once it is established that 

an agency has adopted a reasonable interpretation of an 

ambiguous regulation, the agency’s interpretation stands even 

if a regulated entity has proposed an interpretation that might 

comport with the statutory scheme equally well or even better. 

IV 

We turn briefly to Howmet’s alternative argument that, 

even if we conclude the EPA’s interpretation of its “spent 

material” regulation was reasonable, we should nonetheless 

reverse the district court because Howmet was not given fair 

notice of the EPA’s interpretation. Howmet’s second 

argument fares no better than its first. 

“Traditional concepts of due process incorporated into 

administrative law preclude an agency from penalizing a 

private party for violating a rule without first providing 

adequate notice of the substance of the rule.” Satellite Broad. 
16 

Co., Inc. v. FCC, 824 F.2d 1, 3 (D.C. Cir. 1987). In 

determining whether a party was provided fair notice, we ask 

first “whether the regulated party received, or should have 

received, notice of the agency’s interpretation in the most 

obvious way of all: by reading the regulations.” Gen. Elec., 

53 F.3d at 1329. “If, by reviewing the regulations and other 

public statements issued by the agency, a regulated party 

acting in good faith would be able to identify, with 

‘ascertainable certainty,’ the standards with which the agency 

expects parties to conform, then the agency has fairly notified 

a petitioner of the agency’s interpretation.” Id. This court has 

held published agency guidance may provide fair notice of an 

agency’s interpretation of its own regulations. See Star 

Wireless, LLC v. FCC, 522 F.3d 469, 474 (D.C. Cir. 2008). 

One year after the EPA promulgated its 1985 final rule 

defining “spent material,” 40 C.F.R. § 261.1(c)(1), it 

published a guidance manual describing the interpretation it 

adopted with respect to Howmet’s KOH shipments. See 

OFFICE OF SOLID WASTE, U.S. EPA, GUIDANCE MANUAL ON 

THE RCRA REGULATION OF RECYCLED HAZARDOUS WASTES

(1986) (Guidance Manual). The 1986 Guidance Manual

states:

[A] spent material is any material that has been used 

and as a result of contamination can no longer serve 

the purpose for which it was produced without 

processing. EPA interprets “the purpose for which a 

material was produced” to include all uses of the 

product that are similar to the original use of the 

particular batch of material in question. For example, 

EPA cites the case of materials used as solvents to 

clean printed circuit boards . . . . If the solvents 

become too contaminated for this use but are still pure 

enough for similar applications (e.g., use as metal 
17 

degreasers), they are not spent materials. Use of 

slightly contaminated solvents in this way is simply 

continued use of the original material rather than 

recycling of a spent material. However, the solvents 

would be spent materials if they had to be reclaimed 

before reuse or if the manner in which they were used 

was not similar to their original application. . . . As 

[an] example, used plating baths reused directly in 

other plating processes would not be spent materials. 

If used for a purpose other than plating, however, the 

used plating baths would be a spent material. 

Id. at 1–7. The EPA announced the availability of the 

Guidance Manual in the Federal Register. See 51 Fed. Reg. 

26,892, 26,892 (July 28, 1986) (noting the guidance document 

is “designed to assist . . . the regulated community in applying 

the definition of solid waste . . . to determine which materials 

when recycled are solid and hazardous wastes”); see also 

Perales v. Reno, 48 F.3d 1305, 1316 (2d Cir. 1995) (“Due 

process cases have long recognized that publication in the 

Federal Register constitutes an adequate means of informing 

the public of agency action.”). 

 

The EPA’s explanation of the definition of spent material 

in the Guidance Manual should have put Howmet on notice of 

the EPA’s interpretation of its “spent material” definition, and 

Howmet should have been able to determine that, based on the 

EPA’s interpretation, the used KOH it transferred to Royster 

was a spent material. Use as a fertilizer ingredient is not a use 

“similar to” use as an industrial cleaning agent. Thus, even 

assuming the EPA’s 1985 Final Rule and its accompanying 

regulations lacked enough clarity, on their own, to provide 

Howmet fair notice of the EPA’s interpretation of its spent 

material definition, the Guidance Manual, made available to 

Howmet one year after the regulation was promulgated and 
18 

thirteen years before the conduct at issue here, was sufficient 

to do so. 

V 

 For the foregoing reasons, the judgment of the district 

court is 

Affirmed. 
KAVANAUGH, Circuit Judge, dissenting: 

The Resource Conservation and Recovery Act of 1976 

grants EPA authority to regulate the generation, storage, 

transport, treatment, and disposal of “hazardous waste.” As 

relevant here, the statute provides that hazardous waste must 

be “discarded material.” 42 U.S.C. § 6903(5), (27). In 1985, 

EPA issued regulations that construe “discarded material” to 

include certain “spent material.” See 40 C.F.R. § 261.2. A 

material is “spent” if it is no longer suitable for “the purpose 

for which it was produced.” Id. § 261.1(c)(1). A separate 

regulation makes clear that “purpose,” though singular, can 

include multiple purposes. See id. § 260.3(b). 

The key issue in this EPA enforcement action concerns 

the 1985 regulations’ phrase “purpose[s] for which [a 

material] was produced.” The material at issue here – liquid 

potassium hydroxide – is produced and marketed for, among 

other things, use in fertilizer. Yet EPA seeks to impose fines 

on Howmet for shipping liquid potassium hydroxide for use 

in fertilizer simply because Howmet had already used the 

potassium hydroxide as a metal cleaning agent. In justifying 

its enforcement action, EPA claims that the “purpose for 

which [a material] was produced” includes only the material’s 

first use by the purchaser. 

In my judgment, EPA’s argument mangles the language 

of the 1985 regulations. As a matter of plain English, the 

purposes for which a material is produced are not limited to 

how the material is initially used by a purchaser. As Howmet 

cogently argues, “the first use that is made of a material after 

the material is produced simply cannot define or change the 

purpose for which the material was previously produced.” 

Howmet Reply Br. at 5. To be sure, EPA would prevail here 

if the 1985 regulation said that “spent material” is material 

that is re-used. But the regulation does not say anything like 

that. EPA’s current interpretation of the 1985 regulations in 
2 

effect deletes the word “produced” and substitutes the words 

“first used.” EPA’s current interpretation is flatly inconsistent 

with the text of its 1985 regulations. To me, this case begins 

and ends with that rather simple point. 

Courts must not “permit the agency, under the guise of 

interpreting a regulation, to create de facto a new regulation.” 

Christensen v. Harris County, 529 U.S. 576, 588 (2000). 

That’s what EPA is attempting to do here. EPA is seeking to 

expand the definition of spent material – and thereby enlarge 

its regulatory authority. It may be that broader EPA 

regulatory authority in this area would be wise as a policy 

matter. But EPA may not obtain that authority by distorting 

the terms of the 1985 regulations. 

What’s more, EPA’s current interpretation contravenes 

EPA’s explicit statement in the preamble to the 1985 

regulations – namely, that it was not extending its regulatory 

authority to “situations where a material can be used further 

without being reclaimed, but the further use is not identical to 

the initial use.” Hazardous Waste Management System; 

Definition of Solid Waste, 50 Fed. Reg. 614, 624 (Jan. 4, 

1985). EPA now wants to read the 1985 regulations to allow 

it to regulate precisely what the preamble said it could not 

regulate. 

Of course, there is good reason the 1985 regulations did 

not go as far as EPA now wants to. Doing so would violate 

the text of RCRA, the governing statute, which as relevant 

here confines EPA’s authority to regulation of “discarded 

material.” We have held that Congress intended the term 

“discarded material” to carry its “ordinary, plain-English 

meaning” – namely, to cover only material that is “disposed 

of, thrown away, or abandoned.” American Mining Cong. v. 

EPA, 824 F.2d 1177, 1184-85, 1190 (D.C. Cir. 1987); see 
3 

also Ass’n of Battery Recyclers, Inc. v. EPA, 208 F.3d 1047, 

1051 (D.C. Cir. 2000). EPA’s current extension of its RCRA 

jurisdiction to reach materials that, far from being disposed 

of, abandoned, or thrown away, are being used as anticipated 

disregards Congress’s decision to restrict EPA’s authority to 

regulation of “discarded material.” In our Court, Howmet has 

raised a challenge based only on the 1985 regulations, not on 

RCRA, so there is no basis here for further exploring the 

statutory boundaries. But in light of today’s decision, we may 

have to consider in a future case whether EPA’s expansion of 

its regulatory authority transgresses RCRA’s limits. 

* * * 

I would reject EPA’s interpretation of its 1985 

regulations as contrary to the clear language of the 

regulations. Even assuming the regulations are susceptible to 

a range of reasonable readings, EPA’s interpretation is outside 

that range. See Auer v. Robbins, 519 U.S. 452, 461 (1997). I 

respectfully dissent.