Opinion ID: 744479
Heading Depth: 2
Heading Rank: 2

Heading: The Chemical-Specific Objections

Text: 55 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. 56 In order to prevail, CMA must show that the challenged agency decision is arbitrary, capricious, an abuse of discretion, 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, 104 S.Ct. at 2781. 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, 104 S.Ct. at 2781. [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, 105 S.Ct. 1102, 1107-08, 84 L.Ed.2d 90 (1985). 57 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. 58 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 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. 59 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. 60 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 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). 61 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, 94 S.Ct. 2628, 41 L.Ed.2d 226 (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. 62 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 self-evident. 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 2,6--Dimethylphenol (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.
63 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 (C sub10 , C sub11 , C sub12 , and C sub13 ). 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). 64 CMA challenges the rule on the ground that the data relating to chlorinated paraffins cannot support the listing of 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 (C sub10 ), eleven carbon atoms (C sub11 ), etc. Chlorinated alphaolefins, by contrast, are composed almost entirely of chains with twelve carbon atoms (C sub12 ). CMA complains that the EPA improperly relied on studies of chlorinated paraffins without independently testing the C sub12 fraction of the chlorinated paraffin mixture, and that there is no evidence that the C sub12 components are responsible for the observed toxicity. 65 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, 66 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. 67 Id. at 61,463. 68 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 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.
69 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. 70 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). 71 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 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. 72 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. 73 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 because 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. 74 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.
75 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. 76 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 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. 77 Moreover, the EPA has done all that the Guidelines required of it with regard to IPBC. The Guidelines state that 78 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 case-by-case basis for addition to the list. 79 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.
80 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 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.
81 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 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. 82 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.