Document ID: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-caDC-96-05188/USCOURTS-caDC-96-05188-0/pdf.json

Parties Involved:
Carol M. Browner
Appellee
Environmental Protection Agency
Appellee
Troy Corporation
Appellant

Document Text:

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United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued May 7, 1997 Decided August 1, 1997 

No. 96-5188

TROY CORPORATION,

APPELLANT

v.

CAROL M. BROWNER,

ADMINISTRATOR, UNITED STATES ENVIRONMENTAL PROTECTION 

AGENCY AND 

ENVIRONMENTAL PROTECTION AGENCY,

APPELLEES

Consolidated with

Nos. 96-5203 & 96-5204

Appeals from the United States District Court 

for the District of Columbia 

(No. 95cv00980) 

(No. 95cv01673) 

(No. 95cv01910)

-

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William K. Rawson argued the causes for appellants 

Chemical Manufacturers and Troy Corporation, with whom 

Claudia M. O'Brien, David F. Zoll, and John C. Marchese

were on the briefs.

Cynthia A. Lewis argued the cause for appellant NMP 

Producers Group, with whom Alec I. Ugol and Karl S. 

Bourdeau were on the briefs.

Ellen J. Durkee, Attorney, United States Department of 

Justice, and Timothy Burns, Attorney, United States Environmental Protection Agency, argued the cause for appellee, 

with whom Lois J. Schiffer, Assistant Attorney General, Scott 

J. Jordan, Mary F. Edgar, and John A. Bryson, Attorneys, 

United States Department of Justice, were on the brief.

Before: GINSBURG, SENTELLE and TATEL, Circuit Judges.

Opinion for the Court filed by Circuit Judge SENTELLE.

SENTELLE, Circuit Judge: Appellants, chemical manufacturers and associations of chemical manufacturers, appeal from 

the district court's grant of summary judgment in favor of the 

Administrator of the United States Environmental Protection 

Agency ("EPA" or "the Administrator") in actions appellants 

brought seeking to invalidate the Administrator's rulemaking 

which had culminated in the addition of 286 chemicals to the 

Toxic Release Inventory ("TRI") under the Emergency Planning and Community Right to Know Act of 1986 ("EPCRA" 

or "the Act"), 42 U.S.C. § 11001 et seq. Appellants had 

asserted error on the Administrator's part both as to the 

adoption of the list of new chemicals as a whole, and as to 

specific chemicals on the list. Finding only specific error, we 

affirm the judgment of the district court in large part, but 

remand for further proceedings with regard to two chemicals.

I. Background

In 1986, Congress enacted EPCRA, which provides, inter 

alia, that manufacturers, processors, and users of certain 

toxic chemicals must file annual reports of environmental 

releases of those chemicals with the EPA and state environUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 2 of 28
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mental agencies. The EPA and the state agencies, in turn, 

make the information available to federal, state, and local 

governments and the public, including the citizens of communities surrounding covered facilities. See 42 U.S.C. 

§ 11023(h). The requirements for the report are rather 

detailed. It must include, as to each facility at which the 

chemicals are manufactured, processed, or used, the name, 

location, and principal business activities of the facility; a 

certification of accuracy by responsible management officials; 

and, as to each covered toxic chemical known to be present at 

the facility:

(i) Whether the toxic chemical at the facility is manufactured, processed, or otherwise used, and the general 

category or categories of use of the chemical.

(ii) An estimate of the maximum amounts (in ranges) 

of the toxic chemical present at the facility at any time 

during the preceding calendar year.

(iii) For each wastestream, the waste treatment or 

disposal methods employed, and an estimate of the treatment efficiency typically achieved by such methods for 

that wastestream.

(iv) The annual quantity of the toxic chemical entering 

each environmental medium.

42 U.S.C. § 11023(g)(1)(C)(i)-(iv).

The reporting requirement of the Act applies to chemicals 

listed in a document titled "Toxic Chemicals Subject to Section 313 of the Emergency Planning and Community Rightto-Know Act of 1986," now known as the TRI. 42 U.S.C. 

§ 11023(c). The original list, compiled by the Senate Committee on Environment and Public Works and incorporated 

by reference in the statute, included 309 individual chemicals 

and twenty categories of chemicals. Congress did not, however, limit the coverage of the Act to the original list, but 

stated that "the Administrator may by rule add or delete a 

chemical" based on statutory criteria, providing specifically 

that the Administrator may add a chemical when "in his 

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judgment, ... there is sufficient evidence to establish any one 

of the following":

(A) The chemical is known to cause or can reasonably 

be anticipated to cause significant adverse acute human 

health effects at concentration levels that are reasonably 

likely to exist beyond facility site boundaries as a result 

of continuous or frequently recurring, releases.

(B) The chemical is known to cause or can reasonably 

be anticipated to cause in humans

(i) cancer or teratogenic effects, o

(ii) serious or irreversible

(I) reproductive dysfunctions,

(II) neurological disorders,

(III) heritable genetic mutations, or

(IV) other chronic health effects.

(C) The chemical is known to cause or can reasonably 

be anticipated to cause, because of

(i) its toxicity

(ii) its toxicity and persistence in the environment, 

of

(iii) its toxicity and tendency to bioaccumulate in the 

environment,

a significant adverse effect on the environment of sufficient seriousness, in the judgment of the Administrator, 

to warrant reporting under this section [with qualifications].

42 U.S.C. § 11023(d)(2). EPCRA further provides that listing decisions shall be based on "generally accepted scientific 

principles or laboratory tests, or appropriately designed and 

conducted epidemiological or other population studies." Id.

Between 1986 and 1994, the Administrator made little use 

of the statutory power to revise the list, adding only sixteen 

chemicals and deleting twelve. In 1994, the EPA put forth a 

proposed rule adding 313 chemicals and chemical categories

to the TRI. Addition of Certain Chemicals: Toxic Chemical 

Release Reporting; Community Right-to-Know, 59 Fed. 

Reg. 1788. After receiving comments, the EPA determined 

that there was insufficient evidence to include three of the 

chemicals. The EPA also deferred action on 40 chemicals 

and one chemical category for a future rulemaking and added 

a category containing 20 chemicals, three of which had been 

proposed for listing individually. With these revisions, the 

EPA issued a final rule adding 286 chemicals to the TRI. 

Addition of Certain Chemicals: Toxic Chemical Release 

Reporting; Community Right-to-Know, 59 Fed. Reg. 61,432.

II. Analysis

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We review a grant of summary judgment de novo applying 

the same standards as those that govern the district court's 

determination. Doe v. Gates, 981 F.2d 1316, 1322 (D.C. Cir. 

1993). Those standards require us to "determine whether 

there is on the record 'no genuine issue as to any material 

fact.' " Id. (quoting FED. R. CIV. P. 56(c)). In cases like the 

present one, where the district court was reviewing an agency 

rulemaking under the Administrative Procedure Act ("APA"), 

this means that we "review the administrative record directly." Gas Appliance Mfrs. v. Dep't of Energy, 998 F.2d 1041, 

1045 (D.C. Cir. 1993). In so doing, we must determine 

whether the agency has complied with the APA; specifically, 

whether its actions have been arbitrary or capricious, including whether it has acted consistently with its own procedures; 

and whether its applications of its governing law have been 

reasonable. The present appeals call upon us to apply those 

tests to a complex of issues.

Prior to the administrative proceedings leading to the 

present litigation, the EPA established guidelines for the 

evaluation of chemicals which were candidates for addition to 

(or for that matter, deletion from) the TRI, known as the 

"HAZARD ASSESSMENT GUIDELINES FOR LISTING CHEMICALS ON THE 

TOXIC RELEASE INVENTORY," May 26, 1992 ("Guidelines"). In 

the proceedings which we review, the Administrator, at times 

acting through a contractor, generally applied the Guidelines. 

The Guideline-mandated analysis involves two steps: (1) 

"screening" and (2) "hazard evaluation."

In the initial screening stage, the EPA makes what it calls 

a "rapid initial assessment." Guidelines at 1. In this assessUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 5 of 28
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ment, the EPA seeks to evaluate whether the subject chemical is handled in a volume that can be expected to cross the 

statutory threshold for reporting, and to provide an initial 

categorization of the sufficiency of the toxicological effect of 

the chemical to be included in the inventory. Id. at 3. In the 

toxicological categorization, the EPA seeks to classify the 

candidate chemicals into three categories. Initially, the 

Guidelines named these categories "sufficient for listing," 

"may be sufficient for listing," and "insufficient for listing." 

Id. However, the EPA received comments on the Guidelines 

pointing out that this nomenclature was misleading and tended to confuse the screening process with the ultimate listing 

determination. Crediting the comments, the EPA, in the 

proposed rule, adopted the category titles of "high, medium, 

and low priority." 59 Fed. Reg. 1788, 1790.

In the second or "hazard evaluation" step, the Administrator undertook a chemical-specific review to determine whether the hazards presented by the specific candidate were in 

fact sufficient to support listing. Those chemicals classified 

in the low priority screening category at step one were no 

longer considered for listing. Guidelines at 3. As to the high 

and medium categories, the EPA conducted a review of the 

existing data to determine whether the chemical met one of 

the three criteria for listing established in EPCRA § 313: 

that is, whether the chemical "is known to cause or can 

reasonably be anticipated to cause" (1) significant adverse 

acute health effects in humans; (2) any of the following 

effects in humans: "cancer, teratogenic effects, or serious or 

irreversible reproductive dysfunctions, neurological disorders, 

hereditable genetic mutations, or other chronic health effects;" or (3) "a significant adverse effect on the environment." 42 U.S.C. § 11023(d)(2).

After subjecting its long list of chemicals to the two-step 

process, the Administrator came forward with the new list of 

286 chemicals giving rise to the present controversy. Representatives of the chemical industry filed four lawsuits in the 

district court seeking to set aside and enjoin enforcement of 

all or part of the final rule. The district court, in a single 

memorandum opinion, granted summary judgment in favor of 

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the EPA in all four claims. In three of the cases, plaintiffs 

appealed to us for review. In this proceeding, we review 

those consolidated appeals.

In addition to several chemical-specific exceptions to the 

EPA's listing, Chemical Manufacturers Association ("CMA"), 

supported by the NMP Producers Group ("NPG") and Troy 

Corporation ("Troy"), raises four exceptions which are applicable to the entire list of additional TRI chemicals. First, 

appellants contend that the EPA acted contrary to law by 

basing its final listing decisions on toxicity criteria inconsistent with the criteria specified in EPCRA § 313. Second, in 

an argument intertwined with the first, they contend that the 

EPA acted arbitrarily and capriciously by listing chemicals 

without complying with its own guidelines and without presenting sufficient evidence and explanation to establish that 

the chemicals meet the statutorily listed criteria. Third, they 

contend that the EPA acted contrary to law by failing to 

consider the potential for human exposure from environmental releases for any of the chemicals which it listed based on 

chronic health effects. Finally, they argue that the EPA 

abused its discretion and acted arbitrarily and capriciously by 

failing to establish criteria for the consideration of exposure 

and failing to make adequate chemical-specific findings. Before considering the chemical-specific objections raised by 

appellants, we will dispose of each of the general objections.

A. The General Objections.

1. The alleged inconsistency with statutory criteria and 

EPA guidelines.

First, appellants argue that the EPA based its final listing 

decisions on toxicity criteria inconsistent with the criteria 

specified in EPCRA § 313. They point out that Congress set 

a high evidentiary standard for listing. In the subsection 

relevant to appellants' specific objection, the statute specifies 

that the EPA may add a chemical to the TRI based on 

chronic health effects only where there is "sufficient evidence" to establish that the chemical "is known to cause or 

can reasonably be anticipated to cause ... serious or irreUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 7 of 28
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versible ... chronic health effects" in humans. 42 U.S.C. 

§ 11023(d)(2)(B)(ii)(IV). In urging that the EPA did not 

comply with these criteria, appellant CMA acknowledges the 

EPA's claim in its final rule that its senior scientists conducted a thorough hazard evaluation in determining by the weight 

of the evidence whether each chemical met the listed criteria. 

However, appellants go on to remind us that "[s]tating that a 

factor was considered ... is not a substitute for considering 

it." Getty v. Federal Sav. & Loan Ins. Corp., 805 F.2d 1050, 

1055 (D.C. Cir. 1986). They argue that we should not accept 

at face value the EPA's claim to have conducted the evaluation, but should make a "searching and careful inquiry" to 

determine if the agency did in fact consider the necessary 

factors. Id. (quoting Citizens to Preserve Overton Park, Inc. 

v. Volpe, 401 U.S. 402, 416 (1970)). Appellants contend that 

our review of the record in the present case will reveal no 

support for the proposition that the EPA actually did conduct 

the hazard evaluation or weight-of-the-evidence assessment. 

They argue that this case is analogous to AFL-CIO v. OSHA,

965 F.2d 962 (11th Cir. 1992), in which the Eleventh Circuit 

considered an Occupational Safety and Health Administration 

rulemaking that established permissible exposure limits 

("PELs") for 428 chemicals. In that case the Eleventh 

Circuit vacated all the PELs because OSHA inadequately 

articulated its reasons for their promulgation, merely "cit[ing] 

a few studies and then establish[ing] a PEL without explaining why these studies mandated" the agency's choice. Id. at 

976.

CMA joins its argument that the EPA failed to comply with 

statutory standards with a contention that the Administrator 

also arbitrarily and capriciously failed to comply with the 

Guidelines. While this is conceptually separate from the 

statutory argument, CMA almost makes the two arguments 

one by contending that the Administrator telescoped the twostep Guideline analysis into the first step and made its 

decision to list a chemical based solely on what CMA calls the 

"overly broad toxicity criteria" applied in the first step of the 

Guidelines without either determining whether the toxicity of 

the chemical met the more demanding standards of the 

statute, or conducting the hazard analysis required in step 

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two of the Guidelines. Whether this is viewed as a failure to 

comply with the statute, or an arbitrary and capricious disregard of its own procedures, or both, if CMA is correct, then 

the district court erred in granting summary judgment in 

favor of the Administrator, and we must reverse. However, 

we hold that CMA is not correct.

In reaching this conclusion, we are guided by one of the 

cases relied upon by CMA. In Citizens to Preserve Overton 

Park, the Supreme Court held that a reviewing court is not 

"to substitute its judgment for that of the agency." 401 U.S. 

at 416. Instead, we only determine whether the decision was 

arbitrary and capricious, or otherwise contrary to law. In so 

doing, we examine whether the decision was based on the 

relevant factors and was not "a clear error of judgment." Id.

In conducting this review, we show considerable deference, 

especially where the agency's decision rests on an evaluation 

of complex scientific data within the agency's technical expertise. See, e.g., New York v. Reilly, 969 F.2d 1147, 1152 (D.C. 

Cir. 1992). As we have said, we review scientific judgments 

of the agency "not as the chemist, biologist, or statistician 

that we are qualified neither by training nor experience to be, 

but as a reviewing court exercising our narrowly defined duty 

of holding agencies to certain minimal standards of rationality." Ethyl Corp. v. EPA, 541 F.2d 1, 36 (D.C. Cir.), cert. 

denied, 426 U.S. 941 (1976). This review of the factual 

determinations and policy decisions of an agency is governed 

by the APA, which directs us to set aside an agency's decision 

only if it is "arbitrary, capricious, an abuse of discretion, or 

otherwise not in accordance with law." 5 U.S.C. § 706(2)(A).

Moreover, insofar as the agency's determination amounts 

to or involves its interpretation of EPCRA, a statute entrusted to its administration, we review that interpretation under 

the deferential standard of Chevron U.S.A. Inc. v. Natural 

Resources Defense Council, Inc., 467 U.S. 837 (1984). Under 

that standard, in order to hold erroneous the EPA's application of EPCRA in assessing the hazard risk, we would have to 

conclude that its interpretation either ran athwart a clear 

mandate of Congress, or was an unreasonable one. On the 

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lants have established neither unlawfulness, arbitrariness, 

capriciousness, nor a misinterpretation of the statute.

CMA's combined statutory/Guidelines argument begins 

with the proposition that the EPA departed from the high 

evidentiary standard set by Congress for listing and instead 

relied on the less demanding toxicity criteria at the first step 

of the Guidelines. Those criteria are broader than the statute's, and therefore, allowing them to govern is inconsistent 

with the statute. This argument would be a colorable one if 

the EPA had done just what appellants set forth and then 

listed chemicals based on the results of that activity, but that 

is not in fact what occurred. Instead, the broader toxicity 

screen was but the first step. It allowed the agency to make 

the above-described division of the chemicals into three parts. 

Only as to the chemicals found insufficient for listing did the 

agency stop with the toxicity screen. Granted, the agency's 

original misleading nomenclature may have made it seem that 

it had found the evidence as to the other categories of 

chemicals to be "sufficient" or that the evidence "may be 

sufficient," but that was merely nomenclature.

Indeed, as noted above, the EPA in the preamble to the 

proposed rule announced the renaming of the screening categories to the more descriptive terms "high, medium, and low 

priority." As to those chemicals which survived the first 

screening, whether classified as of "high or medium priority," 

or according to the earlier, misleading nomenclature, the 

EPA went on to conduct further proceedings designed to 

achieve compliance with the more rigorous demands of the 

statute. This further process is summarized in documents 

included in the administrative record. See 59 Fed. Reg. 1788, 

1789-90. Although the exact applications of step-two analysis 

varied with the nature of the data available on specific 

chemicals, typically the EPA's contractor reviewed the data 

as to those chemicals surviving the first screen, and senior 

scientists of the EPA reviewed the contractor's report and 

the existing data in what was called a "HERD" review (for 

Health and Environment Review Division of EPA's Office of 

Pollution Prevention and Toxics). Only where a case-by-case 

review of each chemical in one of the two categories revealed 

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that "there was sufficient evidence to establish that the 

candidate chemical met the statutory criteria for addition to 

EPCRA § 313," id. at 1790, did the Administrator add the 

chemical to the TRI.

The AFL-CIO v. OSHA decision upon which appellants 

rely does not suggest a contrary result. As always, of course, 

the question of sufficiency of an agency's stated reasons 

under the arbitrary and capricious review of the APA is factspecific and record-specific. That OSHA had not given sufficient reasons under a different statute applying a different 

(substantial evidence) standard of review on a different factual record would not compel a similar result on our part even if 

that case were a binding precedential decision from our own 

circuit, which, of course, it is not. More specifically, from the 

Eleventh Circuit's decision, it appears that OSHA's failure to 

give reasons in that case was systemic and purposeful. Here, 

as we have already noted, the EPA undertook an on-therecord review of the data as to each candidate chemical. 

While we might describe the record of some of the chemicalby-chemical reviews as "brief" or "sketchy," that would not 

necessarily be pejorative. That a standard, such as the 

statutory standard in this case, is strict, does not require that 

the evidence to meet it be voluminous, and especially does not 

require that it be voluminously recorded. CMA's generic 

challenge to the sufficiency of the listing process fails. Insofar as appellants contend that the record is insufficient with 

respect to specific chemicals, we will address those contentions in our chemical-by-chemical analysis infra.

2. "Human exposure" objections.

Appellants, led by NPG, object to the refusal of the EPA to 

assess the likelihood of exposure of humans to each candidate 

chemical before listing it on the TRI as a chemical that "is 

known to cause or can reasonably be anticipated to cause" the 

undesirable consequences listed in 42 U.S.C. § 11023(d)(2)(B) 

& (C). Appellants argue first that the EPA's failure to 

consider exposure is a violation of the statute, and, alternatively, that the EPA's adoption of the policy of nonconsideraUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 11 of 28
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tion amounts to an unlawfully adopted legislative rule. Neither argument is meritorious.

a. The statutory argument.

NPG, in an argument adopted by the other appellants as to 

other chemicals, contends that the EPA failed to comply 

with the governing statute in adding NMP (N-Methyl-2- 

Pyrrolidone) to the TRI. NMP is a general purpose solvent 

used in paint stripping, lube oil extraction, and several industrial and agricultural applications. According to appellants, 

and undisputed by the EPA, NMP is chemically and heat 

stable, and has a low vapor pressure (that is, does not readily 

change from liquid to gas forms), making inadvertent atmospheric release unlikely. NMP is expensive and easily recycled, so that facilities have both the economic incentive and 

technical capability to minimize release into the environment. 

If released into water, NMP, being readily biodegradable, 

quickly breaks down into harmless and naturally occurring 

substances. Therefore, appellants contend, human exposure 

to a release of the chemical in a sufficiently large quantity to 

result in an adverse effect is highly unlikely. Appellants 

assert that in the face of that unlikelihood, the EPA violated 

the statutory standard by listing NMP as a TRI chemical that 

"can reasonably be anticipated to cause" adverse reproductive 

and developmental effects under subsection (B). 

Appellants' argument is that no matter how toxic NMP 

might be, Congress could not have contemplated that such a 

chemical would be listed under the TRI as no substance "can 

reasonably be anticipated to cause" adverse health effects in 

humans unless it is likely to come into contact with humans 

(e.g., escape) in sufficiently large quantities to produce such 

adverse effects. Indeed, NPG contends that the EPA's 

contrainterpretation fails at the first step of the Chevron

analysis: that is, that it runs contrary to the unambiguously 

expressed intent of Congress. In the view of NPG, by using 

the quoted language of reasonable anticipation, Congress 

must have intended the EPA to consider likelihood of exposure in making listing decisions. We disagree.

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It is not the case that the congressional language mandating listing of a chemical that "is known to cause or can 

reasonably be anticipated to cause in humans" the enumerated adverse effects unambiguously incorporates the likelihood 

of contact between humans and the chemical. A simple 

analogy quickly refutes NPG's argument that the language is 

unambiguous. Consider a herpetologist and a student contemplating a reptile imprisoned in a glass cage. The student 

asks, "Can that snake's bite reasonably be anticipated to 

cause death in humans?" The scientist replies, "Yes." The 

scientist is not commenting on the likelihood of the serpent's 

escape, only the toxicity of its venom. Concededly, his answer could be taken to mean, "Yes, it is likely that this 

creature will escape, bite someone, and kill them." But that 

is certainly not the unambiguous purport of his words. Even 

so is the statutory language of Congress. It is conceivable 

that Congress may have contemplated release in its phrasing 

of the standard, but that is certainly not unambiguously the 

case. Therefore, under Chevron, as the wording of the 

statute is at most ambiguous, the most that can be required 

of the administering agency is that its interpretation be 

reasonable and consistent with the statutory purpose. Chevron, 467 U.S. at 843. The EPA's interpretation of the 

statutory phrase is not only reasonable, but indeed well 

justified.

Although we might simply say that the agency's interpretation of the words of Congress is reasonable on its face, in the 

same way that the student might reasonably understand the 

scientist to be describing the venomous characteristics of the 

snake, the EPA offers us stronger and more specific support 

for its interpretations. Section 313(d)(2) of EPCRA has three 

subheadings. Subheading (A) provides for listing based on 

causation of "significant adverse acute human health effect at 

concentration levels that are reasonably likely to exist beyond 

facility site boundaries as a result of continuous, or frequently 

recurring, releases." 42 U.S.C. § 11023(d)(2)(A). Subheading (B), the one implicated in the NMP controversy, provides 

for listings based on causation in humans of cancer, teratogenic effects, or "serious or irreversible" listed adverse effects including the provision implicated here: "other chronic 

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health effects." 42 U.S.C. § 11023(d)(2)(B). Subheading (C) 

provides for listing based on causation, as a result of toxicity, 

environmental persistence, or bioaccumulation, of "a significant adverse effect on the environment...." 42 U.S.C. 

§ 11023(d)(2)(C).

Neither (B) nor (C) contains the language found in (A) 

requiring that causation be under the described circumstances of "concentration levels that are reasonably likely to 

exist beyond facility site boundaries as a result of continuous, 

or frequently recurring, releases." If that language were 

present in the other two subsections, NPG's argument that 

Congress intended the EPA to consider the likelihood of 

accidental escape or other contact with humans would be 

much strongerperhaps irrefutable. Indeed, if that language were in the statute, the EPA might well have interpreted the statute as appellants desire. But the language is 

not in the relevant subsections of the statute. The EPA 

reminds us that "where Congress includes particular language in one section of the statute but omits it in another, it 

is generally presumed that Congress acts intentionally and 

purposely in the disparate inclusion or exclusion." Keene 

Corp. v. United States, 508 U.S. 200, 208 (1993) (internal 

punctuation and citation omitted). Thus, it is, to say the 

least, not unreasonable for the EPA to have concluded that 

Congress meant to include consideration of the likelihood of 

human exposure to chemicals governed by (A) but not those 

governed by (B) or (C). We therefore reject appellants' 

statute-based argument.

b. The administrative argument.

Correctly anticipating that we might hold the EPA's interpretation of (B) and (C) not inconsistent with the statute on 

the question of exposure, appellants put forth a fallback 

position. They argue that even if the interpretation was not 

substantively erroneous, its adoption was procedurally flawed.

The EPA expressed its policy regarding consideration of 

exposure in the preamble to its final rule. 59 Fed. Reg. 

61,432, 61,440-42. In that preamble, the agency notes that it 

has received many comments concerning the issue of whether 

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the statutory criteria "include an implicit exposure and thus 

risk component." Id. at 61,441. The agency then states that 

it has "reviewed its positions in [that] area," and expresses its 

"agree[ment] with many of the commentators that there are 

limited circumstances under which it is appropriate ... to 

consider exposure factors for listing decisions under 

§ 313(d)(2)." It lists the circumstances under which "exposure considerations are appropriate" as including only determinations under subsection (A), under subsection (B) for 

chemicals of "low to moderately low" toxicity, and those 

under subsection (C) "that are low or moderately ecotoxic" 

without certain described serious adverse effects.

NPG mounts a two-front assault on the statements regarding exposure analysis in the preamble. First, it contends that 

the EPA's position amounts to a change in policy without a 

reasoned justification. Second, it argues that the preamble is 

a legislative rule that had not been properly promulgated. 

On review, we uphold the district court's determination that 

the EPA's policy expressed in the preamble survives both 

challenges.

First, NPG argues that the EPA's exposure policy pronouncement in its preamble constituted a change in agency 

policy. Appellants remind us that an agency is obligated "not 

to depart without reasoned explanation from its prior conclusions." National Ass'n for Better Broadcasting v. FCC, 849 

F.2d 665, 669 (D.C. Cir. 1988) (internal punctuation omitted). 

This is undeniably correct. As the Supreme Court stated in 

an analogous context, "an agency changing its course by 

rescinding a rule is obligated to supply a reasoned analysis 

for the change beyond that which may be required when an 

agency does not act in the first place." Motor Vehicle Mfrs. 

Ass'n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 42 

(1983). Were the EPA to abandon a long-held exposure 

policy and take a new direction we would, as urged, require a 

thorough explanation of its reasons for doing so. Yet, the 

EPA's pronouncement in its preamble of its exposure policy is 

not a change in course. With one exception, the EPA has 

consistently stated, as it does in this rulemaking, that it will 

consider exposure under subsection (B) only when the chemiUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 15 of 28
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cal was of "low to moderately low" toxicity. The EPA 

concedes that in one case the agency denied a petition to add 

inorganic fluorides to the list based in part on the insignificance of industrial releases of the chemicals. The agency 

stated, "EPA has concluded that potential exposure must be a 

consideration in making decisions to add chemicals to the 

list." 52 Fed. Reg. 20,142, 20,145 (May 29, 1987). While 

some inorganic fluorides cause serious chronic health effects 

at high doses, the EPA determined that the exposure required for such effects to occur was not likely to result.

Whatever the reasons for the EPA's determination in that 

case, the agency has long maintained that it would consider 

exposure under subheading (B) only for low toxicity chemicals. The inorganic fluorides petition was denied over ten 

years ago. Since that time, the agency has made several 

dozen listing and delisting decisions under EPCRA. The 

inorganic fluorides case was the only instance in which the 

agency articulated a policy contrary to the one explicated in 

this rulemaking. Under these circumstances we cannot say 

that the agency has departed from prior practice in a way 

that requires more explanation than was provided. If anything, the inorganic fluorides case constituted such a departure, but that is not before us.

We also reject NPG's argument that the exposure policy 

amounts to a legislative rule that should have been issued for 

notice and comment rulemaking under 5 U.S.C. § 553. The 

APA excludes "general statements of policy" from the requirements of section 553. The precise distinction between a 

general statement of policy and a legislative rule is often 

elusive, but in seeking it we have found useful a two-part 

inquiry put forth in American Bus Ass'n v. United States,

627 F.2d 525 (D.C. Cir. 1980). There we said that, first, a 

general statement is one that "does not impose any rights and 

obligations" and, second, that a policy statement generally 

leaves the agency and its decisionmakers free to exercise 

discretion. Id. at 529. See also Community Nutrition Inst. 

v. Young, 818 F.2d 943, 946 (D.C. Cir. 1987). A legislative 

rule, in contrast, is one that: (1) "supplements" a statute; (2) 

"effect[s] a change in existing law or policy"; or (3) "grant[s] 

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rights, impose[s] obligations, or produce[s] other significant 

effects on private interests." National Family Planning &

Reprod. Health Ass'n v. Sullivan, 979 F.2d 227, 237-38 (D.C. 

Cir. 1992). See also Batterton v. Marshall, 648 F.2d 694, 

701-02 (D.C. Cir. 1980); Chamber of Commerce v. OSHA, 636 

F.2d 464, 469 (D.C. Cir. 1980). We will also consider an 

agency's characterization of its own actions, although that 

characterization is not dispositive. See Telecommunications 

Research and Action Center v. FCC, 800 F.2d 1181, 1186 

(D.C. Cir. 1986). Applying these principles we conclude that 

the EPA's exposure policy was exempt from the notice and 

comment requirements of section 553. The EPA's exposure 

policy merely informed the public that the agency would 

exercise its discretion by considering exposure only for low 

toxicity chemicals. The EPA did not thereby curtail this 

discretion; it did nothing more than clarify its own position. 

The policy does not impose rights or obligations or bind the 

agency to a particular result. Chemicals of low toxicity may 

be added despite the policy, just as chemicals of moderate or 

high toxicity are not necessarily added because of it.

Having disposed of appellants' general objections to the 

rulemaking, we will address the chemical-specific objections 

in turn.

B. The Chemical-Specific Objections

1. Diisocyanates category

Isophorone diisocyanate ("IPDI"), 2,2,4 trimethylhexamethylene diisocyanate ("2,2,4 TMDI") and 2,4,4 trimethylhexamethylene diisocyanate ("2,4,4 TMDI") were listed on the 

TRI as part of a category of chemicals known as the diisocyanates category. The EPA listed the category, which contains 

twenty chemicals, under subheading (B) based on chronic 

pulmonary toxicity observed in studies of six of the chemicals. 

CMA argues that the statute does not permit the EPA to list 

chemical categories without demonstrating separately that 

each individual chemical meets the statutory criteria.

In order to prevail, CMA must show that the challenged 

agency decision is "arbitrary, capricious, an abuse of discreUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 17 of 28
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tion, or otherwise not in accordance with law." 5 U.S.C. 

§ 706(2)(A). The final rule will be upheld so long as the 

agency has "acted within its delegated statutory authority, 

considered all of the relevant factors, and demonstrated a 

reasonable connection between the facts on the record and its 

decision." Ethyl Corp. v. EPA, 51 F.3d 1053, 1064 (D.C. Cir. 

1995). In matters of statutory interpretation, the court first 

asks "whether Congress has directly spoken to the precise 

question at issue." Chevron, 467 U.S. at 842. If so, the 

matter is settled, "for the court, as well as the agency, must 

give effect to the unambiguously expressed intent of Congress." Id. at 842-43. "[I]f the statute is silent or ambiguous with respect to the specific issue, the question for the 

court is whether the agency's answer is based on a permissible construction of the statute," id., meaning one that is 

"reasonable and consistent with the statute's purpose." Nuclear Information Resource Service v. NRC, 969 F.2d 1169, 

1173 (D.C. Cir. 1992). At that point, the court need only 

conclude that the agency's understanding of the statute is "a 

sufficiently rational one to preclude a court from substituting 

its judgment" for that of the agency. Chemical Mfrs. Ass'n 

v. NRDC, 470 U.S. 116, 125 (1985).

As discussed above, EPCRA provides that "[a] chemical 

may be added if ... there is sufficient evidence" that the 

chemical "is known to cause or can reasonably be anticipated 

to cause" one of three effects. 42 U.S.C. § 11023(d)(2). In 

the absence of a statutory definition, the EPA defined "chemical" to mean "an individual chemical" or "a category of 

chemicals." Based on this interpretation, the EPA determined that a category of chemicals may be added based on 

sufficient evidence that characteristics common to the category give rise to the effects.

It is not the case that the term "chemical" unambiguously 

excludes "chemical categories." In fact, Congress itself used 

the word "chemical" to include "categories of chemicals" when 

it stated that the original TRI included "those chemicals on 

the list in Committee Print Number 99-169 of the Senate 

Committee on Environment and Public Works." 42 U.S.C. 

§ 11023(c). The list in Committee Print Number 99-169 

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included both individual chemicals and twenty chemical categories, including chlorophenols, glycol ethers, and thallium 

compounds. In light of the surrounding text, therefore, CMA 

cannot successfully challenge the EPA's interpretation under 

step one of Chevron. Moreover, we have no reason, considering the surrounding text, to require the agency to adopt 

CMA's interpretation of "chemical" at Chevron step two. To 

the extent that there is any ambiguity in the term, the EPA 

has put forth an eminently reasonable interpretation. We 

hold that the EPA may add chemical categories to the TRI 

without demonstrating separately that each individual chemical meets the statutory criteria.

CMA also challenges the listing decision on the grounds 

that there was insufficient evidence with regard to IPDI, 

2,2,4-TMDI, and 2,4,4-TMDI because the EPA failed to take 

account of differences between diisocyanates. A diisocyanate 

compound is a molecule composed of two isocyanate groups, 

each consisting of a carbon atom double-bonded to both an 

oxygen atom and a nitrogen atom. Diisocyanates vary in 

their physical and chemical characteristics. A diisocyanate 

may be aromatic, meaning that each of the isocyanate structures is bonded to a benzene ring, or aliphatic, meaning that 

it has no benzene ring. Diisocyanates may be in liquid or 

solid form and exhibit a range of molecular weights and vapor 

pressures. Moreover, some diisocyanates have an isocyanate 

group "para," meaning opposite, from the methyl group in a 

6-carbon benzene ring that is thought to be highly reactive. 

The EPA believes that diisocyanates are appropriately added 

as a category because "members of this category are structurally similar (i.e., each contains the diisocyanate functionality), they induce a similar toxic effect (chronic pulmonary 

irritation), and their toxicity is due to the diisocyanate portion 

of the molecule common to all members." 59 Fed. Reg. 

61,432, 61,442.

The EPA's conclusion that toxicity is caused by the diisocyanate portion of the molecule, and so could reasonably be 

expected in IPDI, 2,2,4-TMDI, and 2,4,4-TMDI, is supported 

by the fact that the six studied chemicals exhibit the full 

range of the category's widely varying physical and chemical 

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properties and each exhibits toxicity. Four of the observed 

chemicals are aromatic; the remaining two are aliphatic. The 

two aliphatic diisocyanates, by definition, do not have the 

highly reactive isocyanate group in the "para" position. Two 

of the six chemicals are solids; four are liquids. The chemicals also vary with respect to molecular weight and vapor 

pressure. In light of the chemicals' varied physical and 

chemical properties, it was reasonable for the EPA to attribute the pulmonary irritation to a common characteristic: the 

diisocyanate portion of the molecule. This determination is 

precisely the type of technical, scientific judgment this court 

will not second-guess. See Environmental Defense Fund v. 

EPA, 598 F.2d 62, 83-84 (D.C. Cir. 1978) ("EPA, not the 

court, has the technical expertise to decide what inferences 

may be drawn from the characteristics of related substances"). 

CMA also argues that the EPA ignored relevant evidence 

by declining to consider a four-week study that exposed male 

rats to IPDI in which the researchers did not find signs of 

pulmonary irritation. We disagree. The agency declined to 

credit the four-week study because it was short-term. Agency guidelines require that generally a study is not considered 

valid unless it is conducted for 90 days or longer. Guidelines 

at 29. In addition, the study did not clearly address pulmonary irritation. The EPA was not required to consider a 

study that did not clearly address the matter at issue. Portland Cement Ass'n v. Ruckelshaus, 486 F.2d 375, 394 (D.C. 

Cir. 1973), cert. denied, 417 U.S. 921 (1974) ("[C]omments 

must be significant enough to step over a threshold requirement of materiality before any lack of agency response or 

consideration becomes of concern."). This is not a case in 

which the EPA has disregarded direct evidence for more 

speculative assumptions. See, e.g., Leather Indus. of America, Inc. v. EPA, 40 F.3d 392, 403 (D.C. Cir. 1994) (EPA's 

reliance on assumptions arbitrary where record contained 

contradictory information). Instead, the agency reasonably 

determined that the study was inapposite. We, therefore, 

conclude that the EPA's decision to list IPDI, 2,2,4-TMDI, 

and 2,4,4-TMDI was consistent with the statute and supported by sufficient evidence.

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CMA also challenges the agency's listing decision because, 

it claims, the agency failed to justify its determination that 

pulmonary irritation as observed in the diisocyanate studies is 

"serious or irreversible" as required by EPCRA. The EPA 

did not include statements in its rulemaking to the effect that 

"pulmonary irritation is a serious health effect because 

breathing is an essential life activity." Such a statement was 

not required because the seriousness of the effects is selfevident. Appellants have raised similar challenges to the 

listing of four of the remaining chemicals. We find these 

challenges equally meritless. With regard to each chemical, 

the agency cited effects such as lesions in the liver, kidneys, 

and spleen 2,6Dimethylphenol ("DMP"); severe gastrointestinal irritation 2-Bromo-2-nitropropane-1,3-diol ("Bronopol"); increased liver-to-body weight ratios and nonneoplastic pathological changes in the stomach 3-iodo-2-

propynyl butyl carbamate ("IPBC"); and reductions in male 

fertility index and female fecundity index N-Methyl-2-pyrrolidone ("NMP"). The agency was not required to discuss in 

detail the seriousness of these effects.

2. Polychlorinated alkanes

The EPA listed a category of chemicals called "polychlorinated alkanes." A polychlorinated alkane consists of chains 

of hydrogen, carbon and chlorine atoms and is obtained 

through the partial chlorination of paraffin, olefin, or acetylene feedstock. The EPA restricted the category to shortchain polychlorinated alkanes, meaning those with carbon 

chain lengths of 10 to 13 carbon atoms ("C10," "C11," "C12," 

and "C13"). The EPA also restricted the category based on 

the number of chlorine atoms and the average chlorine content. Within these parameters, the EPA included polychlorinated alkanes manufactured from each of the different feedstock, although the EPA's listing decision relied exclusively 

on studies of polychlorinated alkanes manufactured from 

paraffins. Based on these studies, the EPA determined that 

polychlorinated alkanes can be anticipated to cause serious 

chronic health effects and significant adverse effects on the 

environment. See 42 U.S.C. § 11023(d)(2)(B), (C).

CMA challenges the rule on the ground that the data 

relating to chlorinated paraffins cannot support the listing of 

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"alpha-olefins," that is, alkanes derived from olefin feedstock. 

When a polychlorinated alkane is manufactured from the 

chlorination of a paraffin it contains compounds with varying 

carbon chain lengths; the chains may have 10 carbon atoms 

("C10"), eleven carbon atoms ("C11"), etc. Chlorinated alphaolefins, by contrast, are composed almost entirely of chains 

with twelve carbon atoms ("C12"). CMA complains that the 

EPA improperly relied on studies of chlorinated paraffins 

without independently testing the C12 fraction of the chlorinated paraffin mixture, and that there is no evidence that the 

C12 components are responsible for the observed toxicity.

The EPA maintains that "the chlorination of paraffins and 

[alpha-olefins] results in products that do not differ significantly structurally, physically, or toxicologically." 59 Fed. 

Reg. 61,432, 61,461. In support, the EPA compares the 

structure of a polychlorinated alkane derived from an olefin to 

the structure of a polychlorinated alkane derived from a 

paraffin. The distinguishing feature between an alkane and 

an olefin is the double bond between the first two carbon 

atoms in an olefin. When the olefin is chlorinated, the 

chlorine atoms attach at the double bond and change the 

double bond to a single bond, thereby changing the olefin to 

an alkane and making it indistinguishable from the polychlorinated alkane derived from the paraffin. As a result,

an [alpha-olefin] and a paraffin, both with the same chain 

length and both with the same degree of chlorination, are 

essentially identical structurally (especially if the degree 

of chlorination is high); the same isomers can be predicted for the chlorination of an [alpha-olefin] and a paraffin 

of the same chain length. The physical properties of 

chlorinated [alpha-olefins] and the corresponding chlorinated paraffins are therefore expected to be very similar.

Id. at 61,463.

As we have stated, the EPA was entitled to list a category 

of chemicals based on its reasonable determination that a 

member of the category caused a relevant ill effect and that 

other members of the category could be expected to exhibit 

the same characteristics. In the case of polychlorinated 

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alkanes, the EPA has adequately defended its conclusion that 

alpha-olefins can be expected to exhibit the same toxic characteristics as chlorinated paraffins. These judgments cannot 

be challenged except with substantial and weighty evidence to 

the contrary. In the absence of such evidence, we give 

considerable deference to the EPA's technical judgment. 

Huls America Inc. v. Browner, 83 F.3d 445, 453 (D.C. Cir. 

1996). We hold that the EPA has presented sufficient evidence for its decision to list polychlorinated alkanes.

3. Bronopol

Bronopol is an antimicrobial agent registered with the EPA 

as a pesticide. The EPA listed Bronopol under subheading 

(B) as a chronic toxicant based on studies indicating that oral 

doses of the chemical produce severe gastrointestinal irritation in rats, mice and dogs. CMA challenges the listing 

decision on the ground that Bronopol produces acute, but not 

chronic, effects.

The categorization of the gastrointestinal irritation as 

chronic, rather than acute, is significant. Under subheading 

(A), an acute toxicant can be listed only if the chemical would 

produce the effects "at concentration levels that are reasonably likely to exist beyond facility site boundaries as a result 

of continuous, or frequently recurring, releases." 42 U.S.C. 

§ 11023(d)(2)(A). As we discussed in part A.2, supra, this 

"exposure" requirement does not apply to subheading (B) 

listings. CMA argues that Bronopol is at worst an acute 

toxicant, is unlikely to be released with any frequency, and so 

could not have been added to the list under subheading (A).

The statute does not provide definitions for either "chronic 

health effects" or "acute health effects," but the agency has 

defined "chronic health effects" to be "any serious or irreversible adverse effects other than those specifically listed in 

section 313 ... that result from long-term exposure to a 

chemical." Guidelines at 29. "Acute health effects" are 

defined, apparently, as effects resulting from short-term exposure to a chemical. See 59 Fed. Reg. 61,432, 61,450. In 

other words, according to the EPA the type of effect is 

defined by the duration of exposure to the chemical rather 

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than the duration and progress of the irritation. In this case, 

the EPA determined that Bronopol presents both acute and 

chronic hazards because dogs given a single high dose of 

Bronopol exhibited irritation, identified by the EPA as acute 

toxicity, while rats given low doses over a two-year period 

also exhibited irritation, identified as chronic toxicity.

Under Chevron, the agency is entitled to deference in its 

reasonable interpretation of an ambiguous statute. We note, 

however, that the agency's approach to distinguishing chronic 

health effects from acute health effects is at least questionable. The common meaning of chronic is: "marked by long 

duration, by frequent recurrence over a long time, and often 

by slowly progressing seriousness: not acute." WEBSTER'S 

THIRD NEW INT'L DICTIONARY 402 (3rd ed. 1961). Acute, 

conversely, is defined as: "having a sudden onset, sharp rise, 

and short course ... opposed to chronic." Id. at 23. One 

would think that a chronic health effect would be a health 

effect of a lengthy duration, marked by frequent recurrence 

over a long time and often slowly progressing. An acute 

health effect would be one that went away quickly. One 

might read the statute to provide that when a chemical causes 

recurring and persistent health problems it may be added to 

the TRI regardless of the likely human exposure. When the 

chemical causes sudden, short-term health effects it would be 

added to the TRI only if the effects were likely to arise as a 

result of frequently recurring releases.

Of course, we will not reverse an agency's interpretation of 

a statute merely because it is not the most obvious one, 

particularly where the litigants have not clearly raised an 

issue of statutory interpretation. We address the issue only 

as it is relevant to our consideration of a challenge CMA has 

raised, namely the apparent inconsistency between the treatment of Bronopol and the EPA's 1994 decision to stay the 

reporting requirements for hydrogen sulfide. In that decision, the agency was considering the results of a 90-day 

inhalation study. Commenters had noted that some of the 

respiratory effects were acute, rather than chronic, because 

they would have undergone repair as soon as exposures 

ceased. The reversibility of the effects was in dispute beUSCA Case #96-5188 Document #287667 Filed: 08/01/1997 Page 24 of 28
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cause the scientists inexplicably "sacrificed" (killed) the animals before reversibility could be established. In response to 

the comments, the agency stated that "some of the respiratory effects cited in the proposal (inflammation, edema, cellular 

necrosis, hyperplasia, and exfoliation) were better characterized as acute effects than as chronic effects." 59 Fed. Reg. 

43,048, 43,049. Even though each effect had been the result 

of 90-day exposure, some of the effects were sudden and 

short-term, that is "acute," while others were long-lasting and 

persistent, that is "chronic." The crucial question was whether the effect "would have undergone biological repair as soon 

as exposures ceased." 58 Fed. Reg. 63,500, 63,509. In other 

words, in that decision the agency did not consider the length 

of exposure to be critical; the distinction depended on the 

length of the effect. As a result, a particular effect could be 

either chronic or acute, not both as suggested by the agency 

in this case.

Absent further explanation of its different approaches in 

the two cases, the agency has acted arbitrarily and capriciously in listing Bronopol as a chronic toxicant. We, therefore, 

remand for further proceedings on this issue.

4. IPBC

IPBC is a white, crystalline solid used in products to 

prevent the growth of mildew and fungi. The EPA listed 

IPBC as a chronic toxicant based on two animal studies. A 

90-day study observed increased liver-to-body-weight ratios 

in rats following exposure to IPBC. A two-year study revealed "non-neoplastic pathological changes" in the rats' 

stomachs. Troy argues that the EPA failed to review the 

studies seriously or to indicate why stomach irritation in rats 

would suggest a potential hazard to humans given differences 

in the species' anatomies. Troy also argues that the EPA 

violated its own Guidelines which, Troy argues, require the 

EPA to present evidence of chronic toxicity in two or more 

species of animals.

Although the agency's presentation of the evidence might 

have been more detailed, the EPA has described its methodology and the results of the studies and has adequately 

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justified the basis for its scientific conclusions. Nor can we 

credit appellants' argument that differences in the anatomies 

of rats and humans invalidate these conclusions. Although it 

is true that humans do not have an organ equivalent to the 

rat's forestomach, the EPA has explained that the rat's 

forestomach contains a tissue known as squamous epithelium 

and this tissue is also found in the human esophagus, pharynx, larynx, oral cavity, and ano-rectal junction. We hold 

that the EPA has presented sufficient evidence to list IPBC.

Moreover, the EPA has done all that the Guidelines required of it with regard to IPBC. The Guidelines state that

chemicals with adequate evidence of chronic toxicity in 

humans and/or two species of animals are considered 

"sufficient for listing" and may be added to the section 

313 list following study validation, whereas chemicals 

with suggestive evidence of toxicity in humans or animals 

may be sufficient for listing and are evaluated on a caseby-case basis for addition to the list.

Guidelines at 29. Although the categories "sufficient for 

listing" and "may be sufficient for listing" appear to conflate 

the toxicity screen with the final listing decision, as we noted 

above, this categorization served only to exclude chemicals 

found to be "insufficient for listing." The Guidelines require, 

and EPA conducted, further proceedings with regard to any 

chemicals not excluded at this first step. This further review 

satisfied the "case-by-case" evaluation required for chemicals, 

such as IPBC, with only suggestive evidence of toxicity based 

on one species of animal. We, therefore, conclude that the 

agency did not act contrary to its Guidelines in listing IPBC.

5. NMP

The EPA listed NMP, a general purpose solvent, under 

subheading (B) based on evidence of developmental and reproductive toxicity. NPG argues that the agency improperly 

relied on criteria less stringent than those imposed by 

EPCRA. In listing the chemical, the EPA relied on a 

document called the Lifecycle Analysis which was completed 

in 1993 as part of the EPA's review of the chemical under the 

Toxic Substances Control Act, 15 U.S.C. §§ 2601-92. Rather 

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than starting from scratch with a separate EPCRA assessment, the EPA piggy-backed the EPCRA listing on the 

TSCA analysis, which took over nine years, considered numerous studies on the hazards of NMP, and concluded that 

NMP presents a "significant risk of reproductive and developmental harm in humans." The EPA then reviewed the 

Lifecycle Analysis and, for purposes of EPCRA, made the 

finding that there was sufficient evidence of the requisite 

hazard. We hold that the EPA's reliance on the Lifecycle 

Analysis was not improper. For purposes of the present 

rule, the EPA reviewed the Lifecycle Analysis and concluded 

that there was sufficient evidence of toxicity to meet the 

listing criteria. In particular, the EPA noted reductions in 

the male fertility index and in the female fecundity index, 

increased incidence of dams with decreased corpora lutea, 

reduced litter size, reduced postnatal survival, and reduced 

pup weight. 59 Fed. Reg. 1788, 1823. This independent 

analysis of the available evidence satisfied the agency's requirements under EPCRA.

6. DMP

DMP is an organic compound used in the manufacture of a 

number of products. The EPA proposed to list DMP under 

subheading (B) based on chronic effects indicated in two 

studies, both conducted by the same researcher in the Soviet 

Union in the 1960s. In both studies, rats which were orally 

administered DMP produced histologic lesions in the liver 

and kidneys. As indicated in the contractor's report, but not 

in the EPA's proposed rule, the Interagency Testing Committee ("ITC") assigned low confidence to the studies because 

details of the experiments were not reported. In particular, 

the studies do not indicate (1) the strain of animals used; (2) 

the number of animals tested at each dose level; (3) the 

number of animals in the control group (one experiment 

only); or (4) the purity of the test article. EPCRA requires 

the agency to rely only on "generally accepted scientific 

principles or laboratory tests, or appropriately designed and 

conducted epidemiological or other population studies." 42 

U.S.C. § 11023(d)(2). EPA Guidelines require it to base 

listing decisions on laboratory tests that "follow an acceptable 

standard protocol." Guidelines at 29. Any one of the flaws 

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indicated in the Soviet studies would render the study invalid 

under EPA regulations, see 40 CFR § 792.185 (1994), which 

require reports of studies to disclose, inter alia, the number 

of animals or other test organisms used, sex, body weight 

range, source of supply, species, strain and substrain, age, 

and procedure used for identification, a description of the 

dosage, dosage regimen, route of administration, and duration, a description of all circumstances that may have affected 

the quality or integrity of the data, and the locations where 

all specimens, raw data, and the final report are to be stored.

The EPA concedes that the ITC had low confidence in the 

studies, but argues that additional data considered along with 

the Soviet studies presents sufficient weight of the evidence 

for listing DMP. 59 Fed. Reg. 61,432, 61,455. The EPA 

asserts that it also relied on a third study in which mice were 

exposed to DMP. The proposed rule does not refer to the 

mouse study. The contractor's report did not cite the mouse 

study, nor did the Integrated Risk Information System, an 

EPA data base containing consensus positions on the toxicity 

of chemicals. Rather, the HERD profile on DMP cites the 

Hazardous Substances Data Bank entry for DMP which, in 

turn, cites the mouse study. If the agency in fact relied on 

the mouse study its reliance is well hidden in the record. We 

hold that the EPA's reliance on tests that were largely 

undocumented violates the agency's Guidelines and evidences 

arbitrary and capricious agency action. We, therefore, remand for further proceedings.

III. Conclusion

We hold, therefore, that the agency has acted arbitrarily 

and capriciously in listing Bronopol without further explanation of its departure from agency precedent. We also hold 

that the agency has acted arbitrarily and capriciously in 

listing DMP based on studies that do not satisfy agency 

regulations. On both issues we remand to the district court 

with instructions to remand the case to the agency for further 

proceedings consistent with this opinion. As to all other 

issues we affirm the judgment of the district court.

So ordered.

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