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Styrene in the Crosshairs: Competing Standards Confuse Public, Regulators
By Jon Entine, September 14, 2011

Science v. Politics—When a popular chemical is in the regulatory crosshairs, the debate invariably passes through advocacy and industry grinders. Crusaders and apologists go head to head. Hysteria builds. Minds fog. Legislators panic. Bad regulations get passed or reasonable ones get shelved. The public loses.

It’s a stale script, but it unfolds time and again. The latest case involves styrene. While it is natural occurring, it’s also produced synthetically. It’s found in many products, including latex paints, carpet backings, bathtubs, shower stalls and most commonly as an ingredient in polystyrene containers that come in contact with food. Think Chinese take-out food.

In June, the Department of Health & Human Services’ National Toxicology Program (NTP) classified styrene as “reasonably anticipated to be a human carcinogen” in its mandated 12th report to Congress. What this listing means is very different from how it is being framed by advocacy groups and the media—and this knowledge gap threatens to wreck legislative havoc across the country.

Are we in danger?

"The chemical industry fought the truth, the science, and the public … about the health risks from chemicals that are commonly found in our homes, schools, and workplaces," blogged Jennifer Sass, senior scientist for the Natural Resources Defense Fund (NRDC), when the NTP listed styrene along with formaldehyde. And in case you missed her point that women and children face imminent danger from toxic overdosing, Sass flogged the common use of styrene as a spice, derisively calling it a “synthetic flavoring in ice cream and candy.”

Sass was making a misleading reference to the fact that styrene is found naturally at low levels in a variety of foods, including cinnamon, fruits, vegetables, nuts, meats and beverages, such as coffee. It also can be synthesized for some foods and other uses. Sass was playing politics. She’s a scientist. We can assume she’s aware of the toxicological evidence on styrene, which collectively shows it poses limited or no harm to consumers in its natural or synthetic forms. To research scientists, including government regulators empowered to protect the public, styrene is not a threat to consumers.

“We've tried to make it clear that a listing in the report doesn't necessarily mean that encountering that substance in any minute quantity means you'll get cancer," said NTP associate director John Bucher, during a June press briefing. "But in the instance of styrene, we have what we believe is limited epidemiological evidence of association with human cancers.” Human exposures, he added, are “probably not very large. The evidence that we’ve used for listing styrene is largely from industrial situations.” Phrases like "limited evidence” and "reasonably anticipated" are strewn throughout the NTP’s nine-page report, but absent from accounts by the NRDC and other advocacy groups who cherry-pick health studies.

Dr. Bucher pointedly did not urge consumers or workers to change their behavior in any way. He said he would not alter his use of products that contain styrene. So why would the NRDC and other activists claiming to be pro-consumer blow this out of proportion by playing the “children will be hurt by this chemical” card?

Precautionary politics

This chemophobic narrative derives from the emerging romance with the precautionary principle—the notion, popular in Europe, that a substance should be banned or seriously restricted, even absent hard data and a cause-effect relationship, if it is perceived as potentially harmful. The precautionary notion is not a scientific standard. It is an attitude rather than the kind of clear-cut science-based rule that generally forms the basis for regulation. In its most extreme applications, tradeoffs are not considered, such as the economic or health harms that might be caused from restricting a particular technology or the potential danger of substituting an untested substance for a thoroughly evaluated one.

The US and most of the rest of the world operate under a “risk standard” that requires proof of actual danger before substances are banned. But there are precautionary currents in the US regulatory system. The Environmental Protection Agency, for example, has the leeway to avoid cost-benefit analysis in its decision-making process. This emerging precautionary ethic gives politically appointed regulators the freedom to pick and choose which substances to restrict. It threatens to replace the risk standard long used in the U.S. and in most of the world.

The issue reflects an enduring confusion about “risk” and “hazard” in our regulatory schemata. Risk describes the probability of genuine injury, not just the possibility that danger lurks. The key in risk analysis is setting an appropriate threshold. Under long standing international protocol, as long as a substance doesn't violate a data-defined threshold, it has been allowed onto the market. Until recently, regulators have been ultra-cautious, especially in America—establishing limits hundreds to thousands of times more restrictive than those suggested by studies on sensitive laboratory animals. Proponents of precautionary legislation are pushing further, for a far more radical hazard-based standard.

What makes a chemical harmful? After all, everything, natural and synthetic, is made of chemicals, which are nothing more than building blocks. But with recent advances in bioanalysis, scientists are now able to isolate a thimbleful of a liquid poured into Lake Erie. Our technology is so advanced that parts per trillion of a chemical can often be identified in pure water used for liquid chromatography—or microscopic particles in the human body. So a common belief, promoted by advocacy groups and often misreported by journalists, that nanogram traces of a chemical are automatically “dangerous” or “toxic” is often wrong.  Exploiting fears of trace levels of chemicals, groups like NRDC pressure regulators to lower exposure thresholds based on what can be measured by ultra-sensitive tests and not on what the evidence shows poses an actual risk of danger to humans.

The NRDC’s overarching goal, in the abstract, is laudable. It wants to ensure that government is doing its job to protect society when self-regulation by industry doesn’t respond to market forces. It is determined to push Congress into revamping the Toxic Substance Control Act (TCSA). First introduced in 1976, it needs updating. What the NRDC proposes is another story, however. As a general rule, the NRDC believes that all synthetic substances that comes in contact with children and pregnant women are hazardous, which puts almost every chemical in the crosshairs. But any chemical can be dangerous if the exposure is severe enough. Apples, bananas, basil, broccoli, cabbage, citrus fruits, mushrooms, turnips and many more foods contain naturally occurring chemicals that are toxic when consumed in high enough doses—they cause cancer at large lifelong exposures to laboratory rodents.

Whether a chemical is potentially harmful to consumers who come in casual contact with it, even for industrial workers, depends on how much of it one is exposed to and for whole long. At very low doses, many chemicals are of no concern, noted Bruce Ames, professor emeritus of biochemistry and molecular biology at the University of California at Berkeley, in a recent speech. For example, a single cup of coffee contains 15-20 natural pesticides and chemicals, including styrene, that test positive in animal cancer tests, but they are present in very low amounts. Drink your Joe with equanimity.

“Animal cancer tests, which are done at very high doses of synthetic chemicals … — the “maximum tolerated dose” (MTD)—are being misinterpreted to mean that minuscule doses are relevant to human cancer,” said Ames, who developed the “Ames Test” widely used to evaluate potential carcinogens. “Over half of all chemicals tested, whether natural or synthetic, are carcinogenic in rodent tests”—almost certainly, he said, because the rodents are forced fed a chemical at doses hundreds or thousands of times higher than humans would consume, and for extended periods of time. The test he developed is 50 years old, and is known for regularly turning out false positives.

Flashing danger signs

What about styrene? From a purely science perspective, based on the recent evidence, it’s difficult to understand what motivated the NTP to flash amber about styrene’s industrial uses. To date, no regulatory body anywhere in the world has classified styrene as a human carcinogen, either to workers or the general population. Even in high dosage tests, styrene has not been shown to be a carcinogen. According to the EPA, in industrial uses, during the manufacturing process, workers exposed to styrene at elevated levels over a prolonged period of time could face gastrointestinal problems and eye irritation. Female workers show no documented evidence of any reproductive effects.

The NTP’s decision carries no regulatory weight—it’s a legacy of a 33-year old federal mandate. It has impacted public discourse, however, feeding the jaws of anti-styrene campaigns. As soon as the classification was made public, the Environmental Defense Fund hyped the news on its “I am not a guinea pig” website. Styrene, it wrote, is “associated” with leukemia and lymphoma in workers, and it provided links to two long-term studies that it claimed found elevated leukemia in workers in the styrene-butadiene industries.

Clicking the links, which few people do, made it clear the EDF is misleading. The studies do not conclude styrene is a carcinogen. They reference a “small” association with cancer, but that finding is considered unreliable by researchers because the workers were exposed to butadiene, a confirmed carcinogen. In reaching its risk classification decision on styrene, the International Agency for Research on Cancer (IARC) reviewed these studies and found them unpersuasive, as those workers were exposed to multiple chemicals. Consequently, IARC declined to classify styrene as a likely or known human carcinogen.

EDF also blithely writes, “In animal studies, mice exposed to styrene developed lung tumors and nasal passage linings were damaged.” That research alert first appeared in an industry-financed study in the mid-1990s. Specifically (and ignored in the ‘factual’ presentation by EDF), the studies found lung tumors in exposed mice, but no tumors in rats, even though the rats were exposed to much higher levels of the chemical. Scientists were left with the perplexing question of why exposed mice get cancer, but rats and humans apparently do not. This kind of data dissonance is not uncommon, and begged for further research.

In an attempt to resolve these questions, the styrene industry funded but did not oversee a study on styrene carried out by Dr. Paolo Boffetta of the International Prevention Research Institute in Lyon, France. His team reviewed 11 peer-reviewed studies published between 2002-2009 that addressed this issue. The academic article, published in 2009 in the Journal of Occupational and Environmental Medicine, reached the collective conclusion that the styrene’s Mode of Action in mice is not relevant for human risk assessment because of the way a mouse catalyzes the cells in its airway—uniquely different than both rats and humans. “The available epidemiologic evidence does not support a causal relationship between styrene exposure and any type of human cancer,” the article concluded.

Considering the evidence of styrene’s relative safety, the styrene industry has responded aggressively to the NTP listing. “It’s political and its’ going to hurt the economy,” said spokesperson Joe Walker, who voiced concerns that the listing could prompt state or federal legislators who are unfamiliar with the nitty-gritty science to push for bans. Restrictions could have considerable economic impact. It’s estimated that 90 percent of composite material manufacturers use styrene in their products and there are about 3,000 US composite material companies.

Marcy Ofner, marketing director at Composites One in Woodstock, Illinois said more than 90 percent of her company’s customers, which include boat, track swimming pool and kitchen cabinet makers, use styrene in their products. Marble Works, based in nearby Elgin, uses the chemical to create its cultured marble and granite counter tops. “We’ve been here for 22 years,” said Tim Wienckowski, but it is exploring the option of moving to Canada, which has declared styrene safe, just in case the regulatory fever heats up.

Many suppliers and manufacturers have been traveling to Washington to meet with key Congressmen, more than 60 in all. They’ve found a receptive ear from Ohio Democrat Tim Ryan and Don Manzullo, an Illinois Republican and co-chair of the House Manufacturing Caucus. “We don’t know how far this ruling could go,” Manzullo said. “If you take this to its most extreme, it could wipe out the plastics industry.

Manzullo is trying to build a coalition in the House to get the issue referred to the National Academy of Sciences for an independent scientific review. The industry has also filed a civil suit challenging the NTP’s ruling, claiming it violated many of its procedural guidelines and wasn’t transparent in the evaluation process, charges the government disputes.

Environmentalists pile-on

The debate over styrene has been further inflamed by the confusion of what to do about polystyrene foam, made from the monomer styrene, used to make disposable cutlery, plastic models, CD and DVD cases, smoke detector housings and other products. It’s ubiquitously found in packing materials, insulation and foam drink cups, and sometimes ends up on beaches and landfills, where it can be an eyesore. That’s a solid waste management issue. The pollution has led almost 50 jurisdictions in California to ban its use in food to-go containers. Some Democrats in the California Assembly have been pushing legislation to enact a statewide ban (it would not target packaged goods) that would take effect in 2016, but a vote was tabled until next year.

Estimating the environmental footprint of polystyrene is complicated. Concerned about the impact of its waste products, McDonald’s in the 1980s sought input from the Stanford Research Institute. SRI concluded that polystyrene foam was preferable to paper wrappers because the coating on the paperboard made it nearly impossible to recycle, while the plastic was reusable and consumed less energy in production.

But advocacy groups didn’t agree. They launched a high profile McToxics boycott in the late 1980s, hammering on the pollution issue but conflating it with claims that styrene containers contained toxic chemicals harmful to children, which is not accurate. Egged on by campaigners, kids sent ketchup-smeared plastic clamshells to company headquarters. McDonald’s found itself spending millions trying to defeat state and local plastics packaging bans. The company ended up capitulating, but life-cycle analyses still suggest the move was more politically correct than environmentally sensible. All containers end up in landfills and beaches. Any ban that would target polystyrene without confronting the larger waste disposal challenge is doomed to fail.

The 35-year campaign against styrene is a case study in well-meaning environmentalism gone astray. Scientists must remain open to new evidence. We are developing sophisticated tools to evaluate exposure to chemicals, including examining their impacts on genes and our hormonal system. If the weight of evidence shifts, we have to be prepared to tighten regulations. But acting precipitously based on public anxiety or in response to web campaigns is a dangerous precedent.

That’s exactly what is threatening to happen in the case of styrene. Labeling a chemical "toxic" or a "contaminant" or “possibly carcinogenic” is meaningless. Toxicity is a question of degree; exposure is different from effect. It's becoming increasingly difficult for the public to distinguish genuine risks from chemophobia.

The NTP listing could have unintended consequences. As of now, the Occupational Safety and Health Administration requires labeling for substances listed by the NTP as “reasonably anticipated” to cause cancer. But OSHA is moving toward the United Nation’s Globally Harmonized Standards for Hazard Communication, which do not require it, as there has no definitive finding that the chemical is harmful. That’s led to confusion in the industry, where some companies have chosen to add a warning label, scaring workers and their families, while others have not. This ambiguity has helped feed activist campaigns, which only hinders reasonable consideration of complicated chemical-related health and safety issues.

Bans and tough restrictions make sense only if we gain identifiable health or environmental benefits in exchange. Advocacy groups and their enablers in the breathless media often compound the confusion. With the stakes so high, scientific literacy is no longer a luxury.

Jon Entine is Senior Fellow at the Center for Health & Risk Management at George Mason University and STATS, and is founder of ESG MediaMetrics, a sustainability consultancy.




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