Opinion for the Court filed PER CURIAM.
Concurring opinion filed by Circuit Judge RANDOLPH, with whom Circuit Judge SENTELLE joins.
Opinion concurring in part and dissenting in part filed by Circuit Judge ROGERS.
PER CURIAM:
The opinion of the court is presented in two parts. In the first part, Judge Rogers writes for a unanimous court to introduce the issues presented and to hold that Honeywell International Inc. has standing to challenge the rule on review promulgated by the Environmental Protection Agency (“EPA”). In the second part, Judge Sentelle writes for himself and Judge Randolph on Honeywell’s challenge to EPA’s reliance on economic considerations in promulgating the rule on review, concluding that the rule must be vacated; Judge Randolph writes on the remedy; and Judge Rogers concurs in part and dissents in part, and would remand the rule to EPA for further explanation.
PART I
ROGERS, Circuit Judge, writing in PART I the opinion of the court:
Title VI of the Clean Air Act (“CAA”), 42 U.S.C. §§ 7671-7671q (2004), implements the policies and directives of the Montreal Protocol on Substances that Deplete the Ozone Layer, Sept. 16, 1987, 26 I.L.M. 1550 (entered into force Jan. 1, 1989), in two ways relevant to this appeal: first, by setting timetables for phasing out production and importation of chemicals that deplete the protective stratospheric ozone layer, such as chlorofluorocarbons (“CFCs”) and hydrochlorofluorocarbons (“HCFCs”), and second, by identifying substitutes for ozone-depleting substances [540]*540thus phased out. Among the industrial uses of CFCs and HCFCs is the manufacture of foam products. In 1999 the Environmental Protection Agency (“EPA”) designated HFC-245fa, a non-ozone depleting hydrofluorocarbon (“HFC”) product developed by Honeywell International Inc. (“Honeywell”), as an acceptable listed substitute for HCFC-141b, an ozone-depleting chemical scheduled to be phased out in 2003, for all foam uses. Honeywell now challenges a final rule also authorizing as substitutes for HCFC-141b the use of two ozone-depleting chemicals — HCFC-22 and HCFC-142b — in certain foam end-uses if technical constraints prevent use of an approved listed alternative. Honeywell contends that EPA exceeded its statutory authority and departed from its policy without rational explanation by approving ozone-depleting chemicals because EPA (1) failed to provide adequate notice of its decision to approve HCFC-22 and HCFC142b where its rule had proposed the opposite; (2) had previously approved substitutes that, in relative terms, present a reduced risk to human health and the environment; and (3) improperly considered potential economic impact when rendering its final decision. EPA responds, as a threshold matter, that Honeywell lacks standing, and on the merits, that there was adequate notice, and that Honeywell misconstrues the effect of the listing of an approved substitute chemical and ignores that continued use of ozone-depleting chemicals under the rule turns only on technical feasibility and not costs. On reply, Honeywell also contends that the rule impermissibly delegates certain determinations to the regulated end users. We hold that Honeywell has standing.
I.
Title VI of the Clean Air Act, 42 U.S.C. §§ 7671-7671q, sets restrictions on the use of chemicals known to have ozone-depleting properties as part of the implementation of a set of policies aimed at protecting the ozone layer. Sections 604 and 605 of the CAA, id. §§ 7671c & 7671d, set timetables phasing out, over time, most uses of “Class I” substances (which include chlorofluorocarbons) and “Class II substances” (which include hydrochlorofluorocarbons). As many such chemicals had been put to use in a wide array of commercial applications, the CAA seeks to ensure the availability of ozone-friendly replacements through § 612, id. § 7671k, which establishes the “safe alternatives policy.” Section 612(a) provides that, “[t]o the maximum extent practicable, class I and class II substances shall be replaced by chemicals, product substitutes, or alternative manufacturing processes that reduce overall risks to human health and the environment.” The Administrator of EPA is directed to take several steps to promote this transition, such as recommending research efforts to identify and develop alternatives for Class I and Class II substances. See CAA § 612(b).
As relevant to Honeywell’s petition for review, the Administrator must also “promulgate rules ... providing that it shall be unlawful to replace any class I or class II substance with any substitute substance which the Administrator determines may present adverse effects to human health or the environment, where the Administrator has identified an alternative to such replacement that — (1) reduces the overall risk to human health and the environment; and (2) is currently or potentially available.” CAA § 612(c). The Administrator is required to publish lists of substitute chemicals that are prohibited or permitted for specific uses. Id. EPA has implemented CAA § 612 through the Significant New Alternatives Program (“SNAP”), 40 C.F.R. §§ 82.170-82.184 (2004), which establishes criteria and procedures for listing [541]*541chemicals as approved substitutes for chemicals phased out pursuant to the CAA. Under the SNAP program, substitutes can be listed as “acceptable” or “unacceptable,” but the regulations also contemplate that substitutes may be listed as acceptable subject to “use conditions” (in which use of the substitute is permitted if certain procedures to minimize environmental and human risk are followed) or “use limits” (in which use of the substitute is permitted for a “narrowed range of use ... because of the lack of alternatives for specialized applications”). See id. § 82.180(b).
In 1993, EPA, acting pursuant to CAA § 606, 42 U.S.C. § 7671e, which authorizes the acceleration of statutory phaseout dates, promulgated bans on the importation and production of three Class II chemicals relevant to this petition: HCFC-141b, HCFC-22, and HCFC-142b. 58 Fed Reg. 65,018, 65,028 (Dec. 10, 1993). The ban is effective in 2003 for HCFC141b, and in 2010 for HCFC-22 and HCFC-142b. Id. However, in 1994, EPA also approved these three hydrochlorofluoroearbons, in the interim, as alternatives, in foam uses, to more ozone-damaging chlorofluorocarbons phased out pursuant to CAA Title VI. See 59 Fed.Reg. 13,044, 13,083 (March 18, 1994). In anticipation of the 2003 ban on the importation and manufacture of HCFC-141b, Honeywell developed a non-ozone-depleting hydro-fluorocarbon, HFC-245fa, to function as a substitute for HCFC-141b in foam applications. In 1999, EPA approved Honeywell’s petition to list HFC-245fa as an acceptable substitute for HCFC-141b in all foam end uses. See 64 Fed.Reg. 68,-039, 68,041 (Dec. 6,1999).
The final rule followed upon intervenor ATOFINA Chemicals, Inc.’s petition of February 17, 1999, requesting that HCFC-22 and HCFC-142b, along with a third chemical, HCFC-124, also be approved as acceptable substitutes for HCFC-141b in foam applications. 65 Fed. Reg. 42,653, 42,656 (July 11, 2000). HCFC-22 and HCFC-142b were already in use in several foam applications, due to EPA’s 1994 approval of those chemicals as CFC substitutes, 59 Fed.Reg. at 13,083, and ATOFINA’s petition, if granted, would have permitted their use as substitutes for HCFC-141b as well. EPA issued a notice of proposed rulemaking, in which it proposed to revisit the status of HCFC-141b, HCFC-22, HCFC-124, and HCFC-142b, and to list all four as unacceptable in all foam applications, both as substitutes for CFCs and for each other. 65 Fed.Reg. at 42,656. The proposed rule, inter alia, had the effect of denying ATOFINA’s petition to allow new users to use HCFC-22, HCFC-124 and HCFC-142b as substitutes for HCFC-141b, but also swept more broadly by effectively proposing to disallow all existing use of the four hydrochlorofluorocarbons. EPA explained that it was proposing to list the chemicals as unacceptable because they had significant ozone-depleting potential and “there are technically feasible zero-ODP [ozone-depleting-potential] substitutes available.” Id. at 42,657-58.
EPA received numerous comments on the proposed rule, many of which focused on the economic impact, particularly to small businesses, of comprehensively delisting the four chemicals at issue; the bulk of these related to the economic hardship that existing users of HCFC-22 and HCFC-142b would face from the proposed ban. After the comment period closed, EPA obtained additional information through new comments, meetings with industry representatives, and a consultant it hired to gather additional information on the feasibility of alternatives to HCFC141b in certain sectors. EPA’s consultant’s report in particular expressed [542]*542doubts about the ability of existing approved alternatives to HCFC-141b to function as viable substitutes across all specific foam end-uses, for economic reasons, such as the cost of HFC-245fa and the cost of equipment adjustments, and for technical reasons, such as the inability of foams manufactured with approved alternatives, at least those that had been tested, to meet certain insulation and space requirements. EPA then published a notice of data availability inviting comment, noting that the new information pertained to, inter alia, “alternatives currently used in each sector and technically viable alternatives.” 66 Fed.Reg. 28,408, 28,408 (May 23, 2001).
After receiving additional comment, EPA issued a final rule implementing its proposed rule in some respects but not others. 67 Fed.Reg. 47,703 (July 22, 2002). First, EPA deferred reaching a decision on whether it would permit continued use of HCFC-141b. Id. at 47,706. Second, EPA abandoned its proposal to limit existing use of HCFC-22 and HCFC-142b as substitutes for CFCs, and allowed existing users of those chemicals continued use of them, noting that “there would be a significant impact on small businesses” if EPA proceeded as proposed and that switching to alternatives “would be difficult and prohibitively costly.” Id. at 47,706-09. Third, EPA implemented its proposal to list HCFC-124 as unacceptable in all foam uses, thus denying ATOFINA’s petition in that respect. Id. at 47,708. Fourth, as to ATOFINA’s petition to allow new use of HCFC-22 and HCFC-142b, as substitutes for HCFC-141b, EPA established different rules for their use based on the specific application. Observing that it “is strongly opposed to listing HCFCs as acceptable where non-ozone-depleting alternatives are available,” EPA listed HCFC-22 and HCFC-142b as unacceptable substitutes for HCFC-141b in several end-uses (polyurethane boardstock, spray foam¡ and appliances) because manufacturers in those sectors had “identified and, in many cases, implemented viable non-ozone-depleting alternatives to HCFC-141b.” Id. at 47,707. For uses in commercial refrigeration, sandwich panel applications, polyurethane slabstock, and other foams, however, which EPA noted were “comprised of a wide range of diverse applications with unique technical considerations,” EPA stated that for these three uses “ozonefriendly alternatives to HCFC141b have not yet been fully developed and implemented across the spectrum of applications.” Id. Because “technical information is scarce for these applications” and it is “difficult to assess, in the absence of detailed information, the viability of alternatives in each narrow application,” EPA expressed concern that some end-users in specific applications might not be able to switch to approved alternatives because of thermal performance, dimensional, and flammability control requirements. Id. at 47,713-14. In the final rule, EPA, pursuant to 40 C.F.R. § 82.180(b)(3), listed HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b within those three end-uses, subject to narrowed use limits conditioned on the user’s ability first to “ascertain that other acceptable alternatives are not technically feasible.” Id. at 47,705. Users would be required to “document the results of their evaluation, and retain the results on file for the purpose of demonstrating compliance.” Id. Notwithstanding its decision to allow some substitution of HCFC-22 and HCFC-142b for HCFC-141b, EPA advised that it was “continuing to review” the end-uses in question “to determine the progress of non-ozone-depleting alternatives,” and that “[a]s non-ozone-depleting alternatives become more widely available, the agency will reevaluate the acceptability of HCFCs [543]*543in these end-uses.” Id. at 47,707. The rule also advised end-users to begin using non-ozone-depleting substitutes as they became available “in anticipation of future EPA action restricting the use of HCFCs.” Id.
Anticipating based on its own market analysis that it will lose sales volume for HFC-245fa if some users are permitted to substitute HCFC-22 and HCFC-142b for HCFC-141b, Honeywell filed this petition for review. See CAA § 307, 42 U.S.C. § 7607. Honeywell, which also manufactures HCFC-22 and sells stockpiles of HCFC-141b and HCFC-142b, does not challenge EPA’s decisions to defer a decision regarding the permissibility of HCFC-141b use, to allow continued use of HCFC-22 and HCFC-142b as CFC substitutes, and to bar use of HCFC-124. Rather, Honeywell’s petition is limited to EPA’s fourth decision, to permit some new use of HCFC-22 and HCFC-142b, as substitutes for HCFC-141b.
II.
As a threshold matter, we address EPA’s contention that Honeywell lacks standing under Article III of the Constitution as well as prudential standing to challenge the final rule. EPA sees this lawsuit as “nothing more than a futile effort to bolster the demands for [Honeywell’s] product, HFC-245fa, in a market that cannot use the product because of technical constraints.” Resp. Br. at 3. For Article III standing, Honeywell points to its “substantial economic injury •— lost sales of HFC 245fa.” Pet. Br. at 13. For prudential standing, Honeywell points to “its role in the market for substitutes to ozone-depleting substance that Congress created in Section 612 of the CAA.” Id. at 14. Essentially, we agree that Honeywell has standing to challenge the final rule for these reasons.
A.
A party wishing to challenge agency action must meet the familiar Article III requirements of injury in fact, traceability, and redressability. See Lujan v. Defenders of Wildlife, 504 U.S. 555, 560-61, 112 S.Ct. 2130, 2136, 119 L.Ed.2d 351 (1992); Ethyl Corp. v. EPA, 306 F.3d 1144, 1147 (D.C.Cir.2002). The final rule authorizes the use of HCFC-22 and HCFC-142b as substitutes for HCFC141b only pursuant to narrowed use limits, conditioned upon the user’s ability first to ascertain and document that non-ozone-depleting alternatives, such as HFC-245fa, are not technically feasible for the specific application of HCFC-22 and HCFC-142b. EPA contends, therefore, that Honeywell suffers no “injury in fact” from having those chemicals listed as acceptable because the rule permits their use only by parties who are not potential purchasers of Honeywell’s product.
While the narrowed use limits may very well cause Honeywell’s injury to be smaller than it would have been if the EPA had approved ATOFINA’s petition outright, they defeat standing only if the court can conclude that there are no additional foam manufacturers that would purchase HFC-245fa if HCFC-22 and HCFC-142b were unavailable. This assumption is not justified on the rulemaking record. The final rule, 40 C.F.R. Pt. 82, Subpt. G, App. K (table) (2004), requires only documentation that alternative chemicals would not satisfy existing “performance or safety requirements,” not documentation that it would be impossible to manufacture foam at all. Presumably some manufacturers would be forced, in the absence of other alternatives, to relax their performance standards and use HFC-245fa. Honeywell has submitted an affidavit from the Vice President and [544]*544General Manager of its Chemicals Operating Unit, Richard V. Preziotti, stating that Honeywell performed a market analysis in 1999 estimating domestic demand for HFC-245fa of approximately 20 million pounds over the period 2003-2010 for use in commercial refrigeration and sandwich panel applications, rigid polyurethane slabstock, and “other foams” categories, assuming users of HCFC-141b would not be permitted to use other HCFCs after December 31, 2002 when production of HCFC-141b was phased out. According to the affidavit, projected losses from the final rule are approximately 2-3 million pounds per year until the phase out of HCFC-22 and HCFC142b in 2010, for a total loss of approximately 16-24 million pounds. EPA has submitted nothing other than its own speculation to counter this evidence. Cf. Sierra Club v. EPA, 292 F.3d 895, 899-901 (D.C.Cir.2002). Some subset of manufacturers that cannot meet existing performance requirements without HCFC-22 or HCFC-142b would presumably, if those chemicals were unavailable, be forced to manufacture foam products that are less commercially desirable by using available alternatives, such as Honeywell’s product, and in the absence of any evidence to the contrary, the affidavit suffices to establish injury in fact. See id. at 900-01.
Similarly unpersuasive, for the same reason, is EPA’s speculation that Honeywell might suffer no injury from the rule even if it could lead to the use of HCFC22 or HCFC-142b by customers who might otherwise purchase HFC-245fa, either because customers might all choose different approved alternatives, because customers permitted to use HCFC-22 and HCFC-142 might nonetheless opt to purchase HFC-245fa, or because Honeywell might sell enough additional HCFC-22 and HCFC-142b, both of which it also manufactures, to compensate for any lost HFC-245fa sales. The Preziotti affidavit speaks directly to this question, stating that Honeywell’s projected revenues from increased sales of HCFC-22 and HCFC142b, neither of which is proprietary, would not offset HFC-245fa revenues lost as a result of the rule. EPA offers no evidence to the contrary. While EPA points to Honeywell’s comments during the rulemaking that HFC-245fa is less expensive than HCFC-142b or HCFC-22, those figures refer to overall system cost, not the cost of HFC-245fa to foam manufacturers; EPA’s consultant’s report indicates the cost of HFC-245fa is meaningfully higher than the cost of competing chemicals.
Honeywell satisfies the traceability requirement because the rule legalizes the entry of a product into a market in which Honeywell competes — the market for approved substitutes for HCFC-141b. EPA maintains that Honeywell cannot demonstrate that it would benefit from a decision listing HCFC-22 and HCFC-142b as unacceptable because doing so would require speculation about the purchasing decisions of third parties not before the court. There is not much to this ehain-ofspeculation objection; it is well established that “[pjarties suffer cognizable injury under Article III when an agency ‘lift[s] regulatory restrictions on their competitors or otherwise allow[s] increased competition.’ ” Wabash Valley Power Ass’n, Inc. v. FERC, 268 F.3d 1105, 1113 (D.C.Cir.2001) (quoting Associated Gas Distribs. v. FERC, 899 F.2d 1250, 1259 (D.C.Cir. 1990)); see also Bristol-Myers Squibb Co. v. Shalala, 91 F.3d 1493, 1499 (D.C.Cir. 1996). As a favorable opinion of the court could remove the competing chemicals from the market, redressability is satisfied as well; as discussed, removal of these competing products, even if customers us[545]*545ing them might have to relax some performance standards to use HFC-245fa, still stands to benefit Honeywell.
B.
In addition to the constitutional requirements of Article III, a petitioner seeking review of agency action must also demonstrate prudential standing to bring the suit; in other words, that “the interest it seeks to protect ‘is arguably within the zone of interests to be protected or regulated by the statute ... in question.’ ” Cement Kiln Recycling Coalition v. EPA, 255 F.3d 855, 870 (D.C.Cir.2001) (per curiam) (“Cement Kiln”) (quoting Ass’n of Data Processing Serv. Orgs. v. Camp, 397 U.S. 150, 153, 90 S.Ct. 827, 829, 25 L.Ed.2d 184 (1970)). The zone of interests test “is not meant to be especially demanding,” excluding only those whose interests are “so marginally related to or inconsistent with the purposes implicit in the statute that it cannot reasonably be assumed that Congress intended to permit the suit.” Clarice v. Sec. Indus. Ass’n., 479 U.S. 388, 399, 107 S.Ct. 750, 756, 93 L.Ed.2d 757 (1987). Our cases have pointed out that a party need not share Congress’ motives in enacting a statute to be a suitable challenger to enforce it; “parties motivated by commercial interests routinely satisfy the zone of interests test,” as “[e]ongruenee of interests, rather than identity of interests, is the benchmark.” Amgen, Inc. v. Smith, 357 F.3d 103, 108-09 (D.C.Cir.2004). If there is reason to believe that a party’s interest in statutory enforcement will advance, rather than hinder, the operation of a statute, the court can reasonably assume that Congress intended to permit the suit.
EPA protests that Honeywell’s interest in enforcing CAA § 612 “is nothing more than a concern [about] EPA’s alleged regulatory laxity,” Resp. Br. at 20, and relies on cases holding that commercial interests
lack prudential standing to enforce regulatory burdens against competitors, for when those interests and those of the statute are not aligned, such suits “[c]arr[y] a considerable potential for judicial intervention that would distort the regulatory process.” Hazardous Waste Treatment Council, Inc. v. EPA 861 F.2d 277, 282-86 (D.C.Cir.1988) (per curiam) (“HWTC II”); see also Hazardous Waste Treatment Council v. EPA, 885 F.2d 918, 924-26 (D.C.Cir.1989) (“HWTC IV”); Cement Kiln, 255 F.3d at 870-71. In HWTC II & IV and Cement Kiln, the court held that manufacturers of pollution control equipment lacked prudential standing to challenge allegedly too-weak pollution regulations, where stronger regulations would lead to increased demand for their products, because of insufficient alignment between the manufacturers’ commercial interests and the environmental purposes of the statute. EPA’s reliance on these cases is misplaced, and EPA overreads them, for prudential standing depends on the nature of the statutory scheme and the competitor interests. Honeywell is suing to enforce a restriction, CAA § 612(c), that is hardly vulnerable to the sort of manipulation that concerned the court in the cases on which EPA relies. A substitute product is either permitted to compete in the market for approved substitutes or it is not. Irrespective of whether the statutory scheme contemplates that competitive interests will advance statutory goals, the court has held that the Hazardous Waste Treatment Council line of cases is inapposite when a competitor sues to enforce a “statutory demarcation,” such as an entry restriction, because “the potentially limitless incentives of competitors [are] channeled by the terms of the statute into suits of a limited nature brought to enforce the statutory demarcation.” Scheduled Airlines Traffic Offices v. Dep’t of Defense, 87 F.3d 1356, 1360-61 (D.C.Cir.1996) (quoting [546]*546First Nat’l Bank and Trust Co. v. Nat’l Credit Union Admin., 988 F.2d 1272, 1278 (D.C.Cir.1993), aff'd 522 U.S. 479, 118 S.Ct. 927, 140 L.Ed.2d 1 (1998)). A suit by a competitor to enforce § 612(c) involves such a demarcation; “entry-like restrictions” are less subject to manipulation than the open-ended emissions standards in HWTC II & IV and Cement Kiln because they “constraint] competitors to a limited role in guarding a congressionally drawn boundary.” First Nat’l Bank and Trust Co., 988 F.2d at 1278. Therefore, the limits of CAA § 612, which restricts challenges to a determination of whether EPA properly decided which substances should be allowed to compete in the market for approved substitutes, sufficiently align Honeywell’s competitive interests with those of the statute to make it a suitable challenger to enforce CAA 612’s terms.
PART II
SENTELLE, Circuit Judge,
writing in Part II the opinion of the court:
Honeywell brings this petition for review arguing that EPA exceeded its statutory authority under Clean Air Act (“CAA”) section 612(c) by approving HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b in certain limited end uses, and therefore allowing those two chemicals to compete with Honeywell’s approved substitute, HFC-245fa. The argument is that EPA premised its approval on the economic impact of denying ATOFINA’s petition (which would have limited the market for substitutes to HFC-245fa). Because section 612(c), Honeywell claims, does not permit EPA to consider economic factors in the approval process, this approval exceeded EPA’s statutory authority under the CAA.
We agree that EPA’s rule considered economic factors and grant Honeywell’s petition for review. We also hold that the only permissible remedy under the CAA is to vacate the rule. We therefore vacate the rule to the extent it approves ATOFINA’s application to list new uses of HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b in certain limited end uses.
I.
HCFC-141b is a blowing agent used to manufacture certain types of foam, primarily foam insulation. The rule under review listed new uses of HCFC-22 and HCFC142b as acceptable substitutes for HCFC141b in some foam end uses and unacceptable in others. EPA found that those two chemicals were acceptable substitutes for HCFC-141b in foam insulation used in commercial refrigeration, sandwich-panel insulation, polyurethane slabstock, and other foams, assuming users intending to use the substitutes ascertain and document that other acceptable alternatives are not “technically feasible.” Protection of Stratospheric Ozone, 67 Fed.Reg. 47,703, 47,711 (July 22, 2002).
EPA justified this conclusion by noting that use of these two substitutes in these end uses was widespread (because they are similar in cost to HCFC-141b), and that there were diverse commercial applications for such foams, each of which had unique “technical considerations.” Id. at 47,713. Those diverse specifications, EPA reasoned, might make it difficult for businesses to switch to other, non-ozone-depleting blowing agents. For example, in foam used to insulate refrigerated truck bodies and insulated rail cars, “it is critical to maintain thermal performance, flammability control, and an absolute outside dimension of a container while maximizing internal dimensions,” and non-ozone-depleting chemicals might not be sufficient to meet these requirements. Id. Also, be[547]*547cause businesses use all three kinds of chemicals, and because of the diverse commercial applications for these foams, EPA believed it had insufficient information to assess the “viability” of alternatives in each application. Id. at 47,714. In some “niche applications ... foam manufacturers may experience difficulties and delays in transitioning to ... alternatives. Given the constraints associated with cost and timing of transitioning to alternatives for small businesses, and the need to facilitate a smooth and equitable transition,” id., EPA believed that the limited use of these substitutes was appropriate if applicants made the required showing of technical infeasibility.
II.
The first issue we must decide is whether this justification for approving new uses of HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b relied on economic factors.1 EPA’s defense to Honeywell’s challenge is not that CAA section 612(c) allows it to consider economic costs in deciding whether a given substitute is acceptable or unacceptable. Rather, EPA’s defense is that the rule under review did not actually consider costs, and instead relied on “technical constraints.”
The flaw in EPA’s position is the assumption that technical constraints exclude considerations of economics. In truth, economic feasibility is part of technical feasibility. It is often possible to fit a round peg in a square hole if enough money is spent to make the round peg fit. In other words, a given change in manufacturing technique may be “technically infeasible” only as compared to some baseline of what it would cost to change the technique.
The rule confirms that the technical considerations considered by the agency intersect with economic considerations. For example, the need for refrigerated truck bodies and insulated rail cars to “maximize] internal dimensions,” id. at 47,713, arises because trucking companies want to transport as much food as possible per truckload to maximize their revenues. Similarly, EPA suggested that the “technical constraints,” associated with switching to non-ozone-depleting chemicals were company-specific, in part because the economic need for businesses to “remain cost competitive” caused widespread use of HCFC-22 and HCFC-142b. Id. The implication is that, economic factors caused those companies to be “locked in” to using these particular chemicals in the manufacturing process, despite the fact that within those end uses, “non-ozone depleting alternatives have been identified and, in limited cases, implemented successfully.” Id. In other words, even though it is technically possible to use manufacturing techniques that do not deplete the ozone layer, it would cost too much to require companies to transition to such techniques given those that, for cost reasons, they have already implemented. This, too, is therefore an economic justification for continuing to allow these companies to use HCFC-22 and HCFC-142b. Finally, EPA noted that the wide variety of products these types of foam are used to manufacture meant that small businesses might economically suffer from a regulatory requirement to use non-ozone-depleting alternatives. EPA noted, specifically, that it was necessary to “level the playing field for small businesses,” and that those businesses might face “constraints associated with cost and timing of transitioning to [548]*548alternatives,” a justification that clearly considers costs. Id. at 47,714. Even if the agency is correct to characterize such concerns as “performance” or “technical” factors, the fact remains that they are also economic factors.
EPA’s reliance on economic constraints requires reversal of its rule. As stated, EPA does not justify the rule on the ground that CAA section 612(c) allows it to consider economic factors in approving a given substitute as acceptable or unacceptable. Nevertheless, EPA’s counsel at oral argument said that EPA’s position is that it may consider costs, and it is at least facially plausible to read the term “available” in section 612(c) to permit consideration of “economic or practicality” concerns. Such a justification cannot pass muster in this Court, however, as the agency did not offer that construction of the statute below. Under Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837, 104 S.Ct. 2778, 81 L.Ed.2d 694 (1984), whether the CAA section 612(c), a statute EPA is charged to administer, permits EPA to consider costs is a matter on which we defer to the agency’s expert judgment, unless its interpretation is unreasonable or if the plain terms of the statute say otherwise. Id. at 843-44, 104 S.Ct. at 2781. In such matters, in which the agency’s rule “is valid only as a determination of policy or judgment which the agency alone is authorized to make and which it has not made, a judicial judgment cannot be made to do service for an administrative judgment.” SEC v. Chenery Corp., 318 U.S. 80, 88, 63 S.Ct. 454, 459, 87 L.Ed. 626 (1943). Whether the agency’s construction of the statute is reasonable under Chevron step two is one such issue, given that the issue requires agency expertise. See Kansas City v. HUD, 923 F.2d 188, 192 (D.C.Cir. 1991). Therefore, even assuming, without deciding, that the text of section 612(c) permits EPA to interpret the statute to consider costs, we must still reverse EPA’s decision and remand to the agency. Without knowing the agency’s interpretation of the statute, we simply have no way of evaluating whether its interpretation is reasonable. True, we do not defer to the EPA on whether section 612(c) clearly requires it to consider costs, but EPA has not advanced that argument before us. Because that argument has not been briefed and is therefore not properly before us, we express no opinion on its merits.
For these reasons, we grant the petition for review.
III.
The second issue we must decide is the proper remedy to correct the agency’s error. We hold that remedy is to vacate the rule to the extent it approves ATOFINA’s application to list new uses of HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b in certain limited end uses.
We read the judicial review provisions of the CAA to authorize us only to vacate, rather than remand, for the sort of challenge at issue here. Honeywell’s challenge is a substantive challenge to the agency’s statutory authority to promulgate the rule. Such challenges are governed by CAA section 307(d)(9), rather than the Administrative Procedure Act. See 42 U.S.C. § 7607(d)(1) (“[t]he provisions of section 553 through 557 and section 706 of Title 5 shall not, except as expressly provided in this subsection, apply to actions to which this subsection applies”).
Section 307(d)(9) provides that “the court may reverse any ... action found to be ... in excess of statutory jurisdiction, authority, or limitations, or short of statutory right.” 42 U.S.C. § 7607(d)(9)(C) [549]*549(emphasis added). Here, the term “reverse” is being used as a term of art to refer to the action of a reviewing court that finds error in a decision under review. In that context, the ordinary meaning of the term “reverse,” at the time section 307(d) was enacted as part of the CAA Amendments of 1977, 91 Stat. 685, 775, was “to overthrow, set aside, or make void (a legal decision) by a contrary decision.” Webster’s New Collegiate Dictionary 991 (1973); see also Webster’s Third New International Dictionary 1943 (1981) (“to overthrow [a legal decision] by a contrary decision: make void [as for error] <the higher court may [reverse] the judgment:^’). “Overthrowpng], set[ting] aside, or mak[ing] void” is language suggesting vacatur. Because this Court’s only source of authority to order a remedy for EPA’s unlawful action is section 307(d)(9), our power is limited to “reversing,” and hence vacating, the offending portions of EPA’s rule below.
We do realize that there is circuit “precedent for the authority of the court to remand without vacating.” Milk Train, Inc. v. Veneman, 310 F.3d 747, 758 (D.C.Cir.2002) (Sentelle, J., dissenting); see also id. at 755-56 (majority opinion) (citing eases). To our knowledge, however, our only case under the CAA holding that remand, rather than vacatur, is the proper remedy is Davis County Solid Waste Management v. EPA, 108 F.3d 1454 (D.C.Cir.1997) (per curiam), which we do not think governs our holding here. In Davis, this Court held that EPA exceeded its statutory authority under the CAA, yet remanded without vacating the rule. Id. at 1459. However, in Davis we did not analyze the actual language of section 307(d)(9), and it does not appear that the parties brought that language to the court’s attention. That decision is therefore not binding on this Court. For “[t]he Supreme Court held long ago that ‘[questions which merely lurk in the record, neither brought to the attention of the court nor ruled upon, are not to be considered as having been so decided as to constitute precedents.’” Checkosky v. SEC, 23 F.3d 452, 492 (D.C.Cir.1994) (per curiam) (separate opinion of Randolph, J.) (quoting Webster v. Fall, 266 U.S. 507, 511, 45 S.Ct. 148, 149, 69 L.Ed. 411 (1925)); see also In re Cheney, 334 F.3d 1096, 1118 n. 8 (D.C.Cir.2003) (Randolph, J., dissenting), vacated on other grounds by Cheney v. U.S. Dist. Court for the Dist. of Columbia, - U.S. -, 124 S.Ct. 2576, 2592, 159 L.Ed.2d 459 (2004). We do not read court cases like we read statutes; unlike statutes, cases derive their binding force from the necessity to avoid revisiting arguments and issues litigated before and decided by those courts, not from the deductive implications of their holdings. The currency of courts is principle, not commands, and we violate no principle laid down by Davis by analyzing the actual words of the statute setting forth the extent of this Court’s remedial power over the EPA’s CAA rules. In light of Davis’s silence on the interpretation of the term “reverse” in section 307(d)(9), Davis is not binding on that question.
In sum, vacatur, rather than remand, is the only remedy we are authorized to impose to correct the error in the rule under review. ■
IV.
For the reasons expressed above, we vacate the rule with respect to those end uses in which EPA permitted limited new use of HCFC-22 and HCFC-142b as acceptable substitutes for HCFC-141b and remand to the EPA for proceedings not inconsistent with this opinion.