Styrene Can Be Listed as Carcinogen On Government Report, Federal Judge Rules

By Robert Iafolla  


Styrene can be listed as a “reasonably anticipated human carcinogen” in a government report identifying substances that potentially put people at increased risk for cancer, a federal judge decided May 15 (Styrene Information and Research Center Inc. v. HHS, D.C. Cir., No. 11-01079, 5/15/13).

Judge Reggie B. Walton of the U.S. District Court for the District of Columbia rejected an industry challenge to the Department of Health and Human Service's inclusion of styrene in the 12th Report on Carcinogens, one in a series of congressionally mandated reports prepared by the National Toxicology Program.

Walton said in his 28-page decision that the carcinogen report provided a rational explanation for the department's decision to list styrene and that its decision is adequately supported by the administrative record.

The Styrene Information and Research Center Inc., a trade association representing 95 percent of the styrene industry, has not decided whether it will appeal the ruling, spokesman Joe Walker told BNA May 16.

Styrene is used to make plastics, rubber, and resins. The annual U.S. styrene production capacity in 2008 was 12.2 billion pounds, according to the Agency for Toxic Substances and Disease Registry. The Occupational Safety and Health Administration estimates that about 90,000 workers are potentially exposed to styrene.

Worker Exposure

Workers exposed to styrene in its reactive form during production are at the highest risk for adverse health effects, while consumers exposed to plastics and other substances made from styrene face a low risk, said Peter Orris, professor and chief of occupational medicine at University of Illinois Hospital & Health Sciences System. Orris joined the legal case in support of the government.

“When the materials are solidified--unless you grind them up and put them in the air--you won't have much of a problem with them,” Orris told BNA. The risks for firefighters and disposal workers who might be exposed to smoke from burning styrene products is less clear, he added.

The inclusion of styrene on the government report on carcinogens, in concert with OSHA's hazard communication standard, essentially ensures that workers will be told that the material is a carcinogen, said Mike Wright, director of health, safety and environment for the United Steelworkers.

Moreover, Wright told BNA that the carcinogen report is an authoritative document that labor advocates can reference in talks with employers to ensure that workers are protected. Occupational safeguards include leak controls so styrene does not escape pipes or reactors, proper venting for any fumes that might be released when reactors are opened, and adequate protective equipment for maintenance workers, he said.

“I've been in plants where there is not a lot of exposure because the styrene is in a closed system,” Wright said. “But there is exposure when [the system] is opened for maintenance.”

Process for Listing

Wright said the Steelworkers joined the case in support of HHS to defend the government's right to communicate the risks of substances after going through a scientifically valid process. The Environmental Defense Fund also joined on the government's side.

SIRC and styrene manufacturer Dart Container Corp. objected to the government's listing process in its lawsuit, which it filed in June 2011--on the same day HHS released the carcinogen report. The lawsuit alleged a series of procedural problems, including violations of the Administrative Procedure Act, the Information Quality Act, and the Federal Advisory Committee Act (41 OSHR 558, 6/23/11).

Walton's Ruling

The May 15 ruling turned aside all of SIRC's arguments. Walton's opinion appears to criticize the lawsuit at times, including his discussion of SIRC's claim that HHS acted in an arbitrary and capricious manner contrary to the Administrative Procedure Act.

“The plaintiffs have taken a scattershot approach in attacking the secretary's listing decision, with little discussion of the actual justification for the decision set for the substance profile for styrene,” Walton wrote. “Insofar as the plaintiffs do attack that document, though, their arguments fall flat.”

For example, Walton cited SIRC's claim that the substance profile for styrene misconstrues a 2006 study supporting the proposition that exposure increases a risk for non-Hodgkin's lymphoma. The judge wrote that the study does say exposure is linked with increase risk for lymphoma and that SIRC does not explain how substance profile misconstrues the study.

Furthermore, he wrote that even if the profile did misconstrue the study, it contains several other studies about the link between exposure and elevated risk of lymphoma--studies that SIRC does not address.

Walton's ruling also laid out the seven-year process that went into the determination to include styrene on the carcinogen report. That process included preparing a 405-page background document surveying scientific knowledge, convening four separate expert panels, and soliciting two rounds of public comments.

No Precedent, But Possible Message?

Walton's emphasis on the strength of the record used to support the government's decision on styrene, as well as his rejection of SIRC's multi-pronged lawsuit, could send a message, said Earthjustice attorney Marianne Engelman Lado.

“The court gave a pretty resounding 'no' to that approach,” Lado told BNA. “I would hope that the chemicals industry would take a look at that opinion and think twice before using that approach again.”


The opinion by the U.S. District Court for the District of Columbia in Styrene Information and Research Center Inc. v. HHS is available at