The opinion of the court was delivered by: Reggie B. Walton United States District Judge
The plaintiffs, Styrene Information and Research Center, Inc. (the "Styrene Center") and Dart Container Corporation, bring this action under the Administrative Procedure Act ("APA"), 5 U.S.C. § 704 (2006), challenging the decision of the United States Department of Health and Human Services ("HHS") to list the substance styrene in its Twelfth Report on Carcinogens. Complaint for Declaratory and Injunctive Relief ("Compl.") ¶ 1. Currently before the Court are cross-motions for summary judgment filed by the plaintiffs; defendants HHS and Kathleen Sebelius, the Secretary of HHS (the "Secretary"); and intervenor defendants United Steel, Paper and Forestry, Rubber, Manufacturing, Energy, Allied Industrial and Service Workers International Union, Environmental Defense Fund, and Peter Orris (the "Intervenors").*fn1 Upon careful consideration of the parties' submissions,*fn2 the Court concludes for the following reasons that the defendants' motions must be granted, and the plaintiffs' motion must be denied.
A. The Report on Carcinogens
The Public Health Service Act directs the Secretary to "publish a biennial report which contains . . . a list of all substances . . . which either are known to be carcinogens or may reasonably be anticipated to be carcinogens." 42 U.S.C. § 241(b)(4) (2006). This so called "Report on Carcinogens" is an "informational scientific and public health document that identifies and discusses agents, substances, mixtures, or exposure circumstances . . . that may pose a hazard to human health by virtue of their carcinogenicity." A.R. at 2467. The Report on Carcinogens is prepared by the HHS's National Toxicology Program ("NTP"), which is staffed by scientists from three HHS components: the National Institutes of Health, the Centers for Disease Control and Prevention, and the Food and Drug Administration. Fed. Defs.' Mem. at 3.
A substance under consideration for listing in the Report undergoes a four step review process. A.R. at 2472. First, the NTP nominates and selects candidate substances, announcing the nominees and soliciting public comments through notices in the Federal Register and NTP publications. Id. Second, after the candidate substances are selected, each substance undergoes a scientific review that entails "(1) preparation of [a] draft background document, (2) review by an expert panel at a public meeting, and (3) internal review by two independent federal committees." Id. Third, the NTP-taking into consideration the listing recommendations of the expert panel, two other scientific review groups, and public comments-drafts substance profiles with listing recommendations for each candidate substance. A.R. at 2473. The draft substance profiles are then peer reviewed by the NTP's Board of Scientific Counselors, which "prepares and submits a peer review report to the NTP that describes the nature and scope of its findings and conclusions concerning the NTP's draft substance profiles." Id. Fourth, the NTP responds to the Board of Scientific Counselors' peer review report, drafts the next edition of the Report on Carcinogens, and transmits the final draft of the report to the Secretary for review and approval. Id. Upon being approved by the Secretary, the Report on Carcinogens is transmitted to Congress and disseminated to the public through notices in the Federal Register and NTP publications. Id.
In determining whether a substance is either "known" or "reasonably anticipated" to be a carcinogen and thus warrants listing in the Report on Carcinogens, the NTP applies the following criteria:
Known To Be Human Carcinogen:
There is sufficient evidence of carcinogenicity from studies in humans, which indicates a causal relationship between exposure to the agent, substance, or mixture, and human cancer.
Reasonably Anticipated To Be Human Carcinogen:
There is limited evidence of carcinogenicity from studies in humans, which indicates that causal interpretation is credible, but that alternative explanations, such as chance, bias, or confounding factors, could not adequately be excluded, or there is sufficient evidence of carcinogenicity from studies in experimental animals, which indicates there is an increased incidence of malignant and/or a combination of malignant and benign tumors (1) in multiple species or at multiple tissue sites, or (2) by multiple routes of exposure, or
(3) to an unusual degree with regard to incidence, site, or type of tumor, or age at onset, or there is less than sufficient evidence of carcinogenicity in humans or laboratory animals; however, the agent, substance, or mixture belongs to a well-defined, structurally related class of substances whose members are listed in a previous Report on Carcinogens as either known to be a human carcinogen or reasonably anticipated to be a human carcinogen, or there is convincing relevant information that the agent acts through mechanisms indicating it would likely cause cancer in humans.
Conclusions regarding carcinogenicity in humans or experimental animals are based on scientific judgment, with consideration given to all relevant information. Relevant information includes, but is not limited to, dose response, route of exposure, chemical structure, metabolism, pharmacokinetics, sensitive sub-populations, genetic effects, or other data relating to mechanism of action or factors that may be unique to a given substance. For example, there may be substances for which there is evidence of carcinogenicity in laboratory animals, but there are compelling data indicating that the agent acts through mechanisms which do not operate in humans and would therefore not reasonably be anticipated to cause cancer in humans.
A.R. at 2468 (footnotes omitted).
B. The Listing of Styrene in the Twelfth Report on Carcinogens
On May 19, 2004, the NTP set in motion the above described review process by nominating twenty-one substances for listing in the Twelfth Report on Carcinogens (the "Report"). See 69 Fed. Reg. 28,940 (May 19, 2004). Among these candidate substances was styrene, id. at 28,943, a liquid derived from petroleum and natural gas byproducts that is used to manufacture a variety of consumer goods, Compl. ¶ 11. The NTP nominated styrene based on the International Agency for Research of Cancer's finding "of limited evidence of carcinogenicity in animals and limited evidence of carcinogenicity in humans" associated with styrene. 69 Fed. Reg. at 28,943.
After selecting styrene as a candidate substance, the NTP prepared a 405-page draft Background Document for the substance, which it released and solicited public comments on in May 2008. See A.R. at 419; 73 Fed. Reg. 29,139 (May 20, 2008). The draft Background Document did not opine on whether styrene should be listed in the Report; rather, it surveyed relevant scientific data on styrene, exploring topics such as human exposure, human cancer studies, studies of cancer in experimental animals, and toxicity. See A.R. at 443-45.
In July 2008, the NTP convened a panel of experts (the "Expert Panel") to peer review the draft Background Document on styrene and recommend whether the substance should be listed in the Report. A.R. at 1110. After conducting this review, the Expert Panel recommended several revisions to the draft Background Document and voted 10-0 that the document, with the panel's recommended changes, was "adequate for drawing conclusions about the carcinogenicity of styrene and for applying the [Report on Carcinogens] listing criteria." A.R. at 1110-11. The Expert Panel further recommended, by a vote of 8-2, "that styrene . . . be listed in the [Report] as reasonably anticipated to be a human carcinogen based on limited evidence of carcinogenicity in humans and sufficient evidence in animals." A.R. at 1697. The two members who voted against the panel's decision did so because, in their opinion, "styrene should be listed as known to be a human carcinogen." Id. The Expert Panel's majority recommendation was based on the following considerations:
(1) evidence of past and present human exposure to styrene in the United States;
(2) evidence of cancer in styrene-exposed workers; (3) induction of lung tumors in mice by styrene by two routes of exposure; (4) the established carcinogenicity in animals and genotoxicity of a styrene metabolite, the 7,8-oxide; (5) evidence for styrene-related DNA adducts and cytogenetic effects in styrene-exposed workers.
Following the Expert Panel's July 2008 meeting, the NTP finalized the Background Document "based on the peer review recommendations of the expert panel and public comments received on the draft document." A.R. at 1194. The NTP also invited public comment on the Expert Panel's listing recommendation for styrene through a notice published in the Federal Register. 73 Fed. Reg. 52,059 (Sept. 8, 2008).
Next, the NTP convened two panels of scientists to review the body of knowledge relating to styrene (including the Background Document, the Expert Panel Report, and any public comments), and recommend a listing status for the substance. A.R. at 2473. The first of these panels, the Interagency Scientific Review Group, recommended by a vote of 6-2 "that styrene . . . be listed in the [Report] as Reasonably Anticipated to be a Human Carcinogen based on limited evidence in humans, sufficient evidence in experimental animals and supporting mechanistic data." A.R. at 1766. The two members who voted against the panel's decision did so because "they felt styrene should be listed as known to be a human carcinogen because of evidence in human cancer studies and mechanistic data (DNA adducts and chromosomal aberrations in humans)." Id. (emphasis added). The second panel, the National Institute of Environmental Health Sciences/NTP Scientific Review Group, recommended by a vote of 7-1 "that styrene . . . be listed in the [Report] as Reasonably Anticipated to be a Human Carcinogen based on limited evidence in humans, sufficient evidence in experimental animals and supporting mechanistic data." A.R. at 1773. The dissenting member of the panel "did not think the available evidence in experimental animals and humans [was] sufficiently convincing to list styrene in" the Report. Id.
The NTP then prepared a draft Substance Profile and listing recommendation for styrene, A.R. at 1779, taking into account the recommendations of the Expert Panel, the scientific review groups, and public comments, A.R. at 2473. It solicited public comments on the draft Substance Profile in December 2008. 73 Fed. Reg. 78,364 (Dec. 22, 2008).
In February 2009, the NTP convened another panel of experts, the Board of Scientific Counselors (the "Board"), to peer review the draft Substance Profile for styrene. See A.R. at 1799, 1814. Unlike the other expert review groups, the Board is not responsible for making a listing recommendation for candidate substances. A.R. at 2473. Rather, it is charged with determining "whether the scientific information cited in the draft substance profile for a candidate substance is technically correct, clearly stated and supports the NTP's policy decision regarding its listing in the" Report on Carcinogens, after which it "prepares and submits a peer review report to the NTP that describes the nature and scope of its findings and conclusions ...