Fire Retardant PBDEs in Washington State: Misplaced Precaution
January 2006
Environmental activist groups like the Washington Toxics Coalition have joined the State Department of Ecology (DOE) and Department of Health in a new effort to ban one of the most common forms of flame retardant compounds known as PBDE. DOE recently released a report claiming PBDEs, and especially the most common and effective form known as deca-BDE, has potential adverse impacts on human health.
Our analysis shows, however, that both departmentsthey rely on several unscientific assumptions and such a ban would, ironically, increase threats to the safety of Washington residents:
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The Department of Ecology and Department of Health report shows that deca-BDE is significantly less toxic than other forms of PBDE. The report also shows that while the level of deca-BDE in human tissue is increasing, the levels found in the human body are dramatically lower than is necessary to cause health effects, according to their own studies.
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Recognizing that deca-BDE is relatively benign, DOE and DOH instead substitute health effects from other compounds like older versions of PBDEs and from PCBs. They assume that deca-BDE will completely degrade into penta-BDE and other forms of PBDE that are more toxic. The studies they cite however, indicate that only about 13% of deca-BDE degrades into these forms, indicating that DOE overstates potential impacts tenfold.
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DOE also argues that because the highly toxic PCBs have a similar structure to deca-BDE, they can simply substitute the impacts from one for the other. This is, however, a wholly unscientific leap of faith. Very similar compounds, such as testosterone and estrogen, are known to have very different effects on the human body. Basing health impacts on this dubious substitution is indefensible.
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Finally, lawmakers will find themselves compelled to lower fire safety standards if they decide to ban deca-BDE. Many activists who support a ban cite the "precautionary principle" which argues that until we have complete assurance that deca-BDE is non-toxic we should ban its use. The irony is that all of the eleven alternative fire retardants identified by DOE are less understood than deca-BDE, which is the most studied fire retardant available. Banning deca-BDE would also require the legislature to ban all of the potential alternatives as well, leaving manufacturers without a method of meeting fire safety standards. Given such an option, it is clear that risk of death and injury threats to health from fire would increase. This increase would undoubtedly outweigh any ephemeral increase in safety from the ban on deca-BDE.
Governments around the world, including the European Union, have been pressured by environmental activists to ban deca-BDE. After looking at the science, those governments have uniformly rejected such a ban. They understand that doing so is not only scientifically dubious but would do more harm than good for the safety of their constituents.
Twelve times a day, firefighters respond to residential fires in Washington state. Many of these fires occur at night, when time to escape is of the essence. The Washington State Fire Marshal reports in their 2004 report that fires that begin in sleeping areas "are reported with the greatest dollar loss." Overall, one fire incident is reported in Washington every 20 minutes.
In an effort to make these fires more survivable, states across the country have created high standards for furniture and computer equipment, requiring them to be flame retardant. Now some claim those standards are having adverse effects, and are encouraging the use of flame retardant materials that are finding their way into human tissues and dust, potentially causing health impacts down the road. These compounds, known as PBDEs (polybrominated diphenyl ether) are used in a variety of materials to increase their flame retardant characteristics from furniture to computers.
Now there is a move in Washington sState to ban all forms of PBDEs, not simply the older generation compounds known as penta-BDE and octa-BDE, but the newest form, known as deca-BDE. This effort is buoyed by a draft report from the Washington State Department of Ecology. On their strongly anti-PBDE web site, they call PBDEs "a fast growing concern." On their page dedicated to the issue they say "Some PBDEs used as flame retardants have been linked to brain and thyroid problems in laboratory rodents."
A close examination of the research, however, shows that there is little evidence that PBDEs, especially deca-BDE, cause health problems. Further, because deca-BDE is a common fire retardant, eliminating them would likely have negative consequences that would significantly outweigh any hypothesized benefits from their ban. In fact, even the Department of Ecology's own study indicates that the only way opponents of deca-BDE can demonstrate impacts is to substitute the impacts from other, more toxic, compounds.
In this paper, we will examine key elements of the Department of Ecology's (DOE) draft report on PBDEs and some of the claims made by environmental activists looking to ban these compounds. Ultimately it will be clear that something else is behind this effort. In fact, everywhere there has been an effort to ban PBDEs (efforts in Europe and California have failed) there has been frequent reference to a standard being pushed by the environmental community known as the "precautionary principle." I will examine this principle at the end of this memo to see if that principle provides guidance on how to deal with PBDEs.
As an increasing number of products use PBDEs, an increasing number of the flame retardants are found in our environment. This shouldn't be surprising and one professor commenting on the campaign in the European Union (EU) to ban PBDEs noted that he "would have been very surprised if they hadn't found chemicals" at low levels in homes.
According to the Department of Ecology, PBDEs enter human tissues from a variety of sources including air, dust and foods. The DOE's report notes that "recent studies indicate that indoor dust may be a greater contributor to human exposures than food, especially for infants and toddlers." This dust comes from a variety of sources, including the breakdown of PBDEs from furniture, computers and other objects. The DOE study notes that other studies show that for adults, the primary source of PBDE ingestion comes from food. It is unclear what particular pathway accounts from most of the PBDEs being found in human tissue.
What is clear is that there appear to be a variety of sources and that they are being found in dust, food and in the environment.
The amount of dust is not the only factor in understanding the effect of PBDEs on the environment. Each compound has different effects on human health, so measuring the level of each type of PBDE is also important. There are primarily three types of PBDEs found in studies: penta-BDE, octa-BDE and deca-BDE. Penta and Octa were previously used as flame retardants but have been phased out in favor of deca-BDE. This understanding is critical because each of these compounds has a different level of toxicity (described below).
In the studies, cited by DOE, all predominant forms of PBDEs were found, but penta-BDE and deca-BDE were the most common types found. Interestingly, however, when scientists examine tissue samples, they do not find penta-BDE and deca-BDE in similar ratios as they are found in the environment. There are two potential reasons. First, as will be discussed below, deca-BDE can degrade into other type of PBDE. Second, deca-BDE tends not to remain in the body the way other types of PBDE do. While penta-BDE has a biological half-life (the amount of time it takes the body to excrete half the amount) of years , deca-BDE has a biological half-life of two days to a week. This short half-life appears to be a factor in deca-BDE's reduced toxicity.
Substitutions and Extrapolations
The Department of Ecology, the Department of Health and environmental activists point to a number of potential impacts as reasons for banning flame-retardant PBDEs. They argue that there are a number of impacts, saying:
"At very low levels PBDEs impair memory, learning, and behavior in laboratory animals. They also affect thyroid hormones and other bodily functions. Most at risk are developing fetuses, infants, and young children."
The data cited by the Department of Ecology, however, does not distinguish between the various forms of PBDE. The data they cite, in fact, indicates that deca-BDE, the only PBDE still being used as a flame retardant, has been studied extensively and that the risk of these impacts with deca are very low. The Department of Ecology's report notes that "Considerable scientific research on deca-BDE has been conducted in recent years," and the results show that it is significantly less toxic than other forms of PBDE.
As a result, Ecology, Health and environmental activists substitute other chemicals in order to extrapolate health hazards. These substitutions and extrapolations, however, are extremely suspect and, in fact, run contrary to the very data provided by the studies they cite.
The first substitution relies on the potential degredation of deca-BDE, also known as BDE-209, to more toxic versions like penta-BDE and octa-BDE. The Ecology report notes that "Indeed, many of the concerns about BDE-209 are driven by its potential to degrade in the environment to less-brominated congeners." When calculating the potential impacts of deca-BDE, the Ecology report actually substitutes the impacts of less-brominated cogeners, like penta-BDE and octa-BDE, entirely. This 100% substitution was also confirmed in a phone conversation with one of the DOE scientists. This substitution is questionable for a number of reasons.
First, there are no studies that show that 100% of deca-BDE will degrade into less-brominated cogeners. The Ecology report dedicates an entire section of the report to the question of how much deca-BDE breaks down in an effort to establish a higher level of toxicity for deca-BDE. The only study cited in the report notes that "When subjected to a total of 90 hours of direct sunlight, the deca-BDE in the samples lost approximately 30% of its total mass and a corresponding increase was found in nona-, octa- and hepta- brominated congeners." But the total amount that degraded into these other forms is even less than this indicates. The study found that more than half of the 30% that did degrade, degraded into other unknown compounds. Thus, only 13% of the deca-BDE in this study, or one-eighth of the amount assumed elsewhere by DOE, actually degraded into other PBDEs. Assuming that 100% would eventually break down is simply unsubstantiated and is an extremely liberal extrapolation of the available studies.
Additionally, studies identifying the presence of PBDEs in the environment, homes and workplaces, clearly identify that deca-BDE is present and has not degraded into other forms. If deca-BDE is present in these studies, it would follow that a significant portion of that type of PBDE isn't degrading. If it was degrading, then we would find less deca-BDE and more PBDEs of other types. This is not, however, what studies find. Studies, cited earlier in the Ecology report, show clearly that deca-BDE is, in many cases, the most common PBDE found in buildings and dust. The presence of deca-BDEs in homes, cited as one reason for banning it, is evidence that claims about it degrading to more toxic forms is incorrect..jpg)
The second substitution is even less supportable, but is actually the source of the most serious claims made by DOE and the Department ofHealthabout the impact of deca-BDE. Instead of using data related to the impacts of deca-BDE, the impacts of the significantly more toxic PCBs are substituted. The rationale for this substitution is explained by the Department of Health and environmental activists saying that "PBDEs have a similar chemical structure to PCBs (polychlorinated biphenyls), which have been studied in humans." The Washington Toxics Coalition echoes this claim saying that "PCBs are a known carcinogen and have been linked to developmental delays, including significant IQ deficits that persist at least through age 11. PBDEs are structurally similar to PCBs and while no studies have been done on humans, laboratory studies have shown that PBDEs can impair memory and learning, alter behavior, delay sexual development, and disturb thyroid hormone levels." Thus, the basis for the comparison is the similarity of the chemical structure between the two molecules (see Figure 1). This extrapolation fails for three clear reasons.
First, similar molecules can have very different impacts on the human body. Take a look, for instance, at the two molecules in Figure 2. They appear very similar and have a similar structure and diverge in only a couple of ways. However, the molecule on the bottom is testosterone, while the molecule on the top is estradiol, which is the primary type of estrogen found in women during reproductive years. These two molecules could not have a more divergent impact on the human body. The obvious conclusion is that extrapolating similar impacts on humans from somewhat similar chemical structures is inexact at best and pure guesswork at worst..jpg)
Second, the Department of Ecology admits that while there PBDEs are similar in structure, there are significant differences in impact between deca-BDE and other forms of PBDE. Deca-BDE is much less toxic than either of these types of PBDE. According to studies cited by DOE, penta-BDE is about 15 times as toxic as deca-BDE in studies of developmental neurotoxicity. If there can be significant variation between similar structures of the same type, why is it defensible to assume that structures that are more divergent, like deca-BDE and PCBs, would have similar results?
Finally, why would we assume that the chlorine found in PCBs would have a similar impact as the bromine found in deca-BDE? For instance NaCl is salt, whereas NaBr is a "used as a hypnotic, anticonvulsant, and sedative in medicine." NaBr is not something you would put on your fries. Mixing and matching chemicals and assuming similar results simply isn't sound.
In a discussion with a DOE scientist, it was argued that the reason that we could assume these are similar is that similar types of impacts were seen from deca-BDE as in tests with PCBs. This misses the point because there are molecules that are very different from PCBs or PBDEs that have similar impacts. We would not argue that saccharin is similar to a PCB simply because both cause cancer in lab tests.
Why these substitutions are attempted at all is quite strange. There is no shortage of study on the effects of deca-BDE, as has already been noted by Ecology itself (see note 12). The only apparent reason one would substitute the impacts from other, more toxic, chemicals would be to grossly exaggerate the potential impacts. It is not surprising that some environmental activists would do this. It is not responsible, however, for governmental agencies to do the same thing, using in many cases almost the exact same words as partisan activists in their arguments to justify this substitution.
One of the most difficult aspects of analyzing the potential impacts of a ban on certain types of chemicals is creating a credible apples-to-apples comparison of potential costs. The most difficult element of this is creating a dollar value of the various costs involved in these decisions. How would one go about answering the question of what is more important, a single potential death or a fifteen percent cost increase in computers or fire-retardant furniture and computer equipment? These calculations assume that because there is a finite amount of money available to address threats to human health, we can make a reasonable calculation about costs of saving lives. For instance, legislators would be more justified in spending $1 per person to reduce the risk of a threat that increases cancer by 1-per-100,000 people than spending $1 to reduce the risk by 1-per-1,000,000 people.
Going beyond that, gets very difficult. What if the comparison is between reducing four potential deaths per year and an increase in costs for one million people. This is exactly what the DOE tries to do in their "Cost Benefit Analysis Tables." With the difficulties involved, it is understandable that the effort falls short. There are, however, a number of strange choices made in the effort to quantify the costs, and numerous potential costs that weigh against a ban are simply left out.
For instance, the cost benefit analysis looks only at the cost of banning PBDEs in computers and television . The justification for this is that most deca-BDE is found in TV housings. The Ecology report cites a study that estimates that "TV enclosures are reported to account for approximately 45-80% of the Deca-BDE use in the U.S." Thus, the Department of Ecology sent questionnaires and attempted to make contact with companies across Washington to assess the potential impact of banning the substance. This effort fell short and the Department of Ecology admits in their analysis that "Ecology had intended to use the survey data to do the following calculation but was unable to do so because of problems with the survey." They simply did not receive enough responses to be able to make a credible calculation..jpg)
The analysis suffers from other errors as well. The source of the claim that most deca-BDE is found in television housings is a group working to eliminate PBDEs. There is an incentive to overestimate the number of PBDEs from televisions because it is less clear these uses save human lives. Deca-BDE is used as fire-retardants in TVs and computers and a study in the United Kingdom found that 1 in 10 fires were caused by electronics equipment and wiring.
In the cost-benefit analysis, the Department of Ecology report estimates that PBDEs will lead to four cancer deaths a year along with a number of health impacts. They estimate that each death is worth $4 million. This accounts for much of the total cost from health impacts of PBDEs in the final spreadsheet comparing costs (it is also worth noting here that these four deaths are based on the erroneous calculations of impact outlined above). On the other side of the ledger, however, they don't account for any lives saved from the flame-retardant capabilities of deca-BDE. There are a variety of examples of how deca-BDE have saved lives and it is estimated that they save hundreds of lives in the U.S. each year. The lives saved from these uses are not accounted for, leaving a significant potential cost-benefit unaccounted for in the analysis. Ignoring this benefit actually ignores the primary reason PBDEs are used.
Another potential cost not accounted for in the DOE's analysis is the environmental impact of potential substitutes. As noted above, the reason deca-BDE has become popular is that it is perhaps the most effective fire retardant and standards, both at the state and national level, for the fire safety standards are increasing. It is unlikely that the government would reduce fire safety standards as part of an effort to ban deca-BDE, so any analysis would have to estimate the potential environmental impacts of any substitute flame retardant material. Ecology's report does discuss several alternatives, but the level of understanding about the potential environmental impacts is less than deca-BDE. Substituting these would be a gamble. In some cases the potential alternatives are ironic given the analysis above.
For instance, one of the alternatives listed is Saytex BT-39. Like PBDEs, it is brominated and has a structure similar to PBDEs. In the report's analysis of potential toxicological impacts, most of the impacts are unknown and in other places it simply says "not expected to be acutely toxic." This is not the only potential alternative, but it highlights the danger of banning one compound hoping that its replacement will be better. Given the amount of research already done on PBDEs and its extremely low level of impacts, it is not unreasonable to assume that there would be offsetting costs due to the toxicity of any replacement.
This assumption is not only prudent, but meets the standard that many who want to ban PBDEs set themselves. This standard is known as the "precautionary principle" and encourages regulators to ban potentially toxic chemicals even if there is no evidence. This principle, however, can lead to strange conflicts and actually relies on ignoring key information to make it work.
The Paralysis of the Precautionary Principle and PBDEs
The Precautionary Principle has a variety of definitions, but the definition provided by the Lowell Center for Sustainable Production is typical of the formulations. According to their web page:
The principle was characterized in the 1998 Wingspread Statement on the Precautionary Principle as: "when an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically." (emphasis added) The statement listed four central components of the Principle: (1) taking preventive action in the face of uncertainty; (2) shifting burdens onto proponents of potentially harmful activities; (3) exploring a wide range of alternatives to possibly harmful actions; and (4) increasing public participation in decision-making. Precaution is underscored by a duty to uphold the basic human right of each individual (and future generations) to a healthy, life-sustaining environment.
The principle calls for action on environmental issues even when science is incomplete and puts the burden on those who oppose actions like banning PBDEs. The primary sponsor of the effort in Washington to ban deca-BDE, the Washington Toxics Coalition, says on their web page that "The Washington Toxics Coalition embraces the Precautionary Principle as the basis of our approach to human and environmental health."
This creation of a guilty-until-proven-innocent standard is a clear attempt to shift the balance of power in environmental discussions. Much has been written about the standard's flaws so this paper examines only a couple of flaws in this particular rationale for legislation banning PBDEs.
First, while it calls for taking preventative action in the face of uncertainty, it assumes that banning a substance or limiting its use is "preventative." In this way it encourages regulators to ignore potential countervailing costs to such actions, or at least place a higher burden on those providing countervailing costs. This puts regulators in the strange position of counting the same potential impacts in two ways - counting health impacts from use of a chemical as greater than similar health impacts from not using the chemical. As this paper argues above, it is already very difficult to come up with apples-to-apples comparisons in issues relating to the cost-benefit analyses regarding environmental impacts. The precautionary principle would make it even more difficult by adding a further subjective element even when comparing apples-to-apples health impacts. This subjectivity is actually a step away from scientific rigor, making decision making more random.
In the case of PBDEs, this would mean that regulators, trying to balance potential health impacts from continuing the use of PBDEs versus the loss of one of the most effective fire retardants, would assume that the potential impacts from continuing PBDE use would be greater until proven otherwise. Meeting that standard might simply be impossible because it is unlikely that uncertainty could ever be eliminated.
The second flaw is that the precautionary principle would encourage regulators to ban PBDEs, but would leave us without suitable alternatives. Any formulation of chemicals that looked to take the place of deca-BDE would face the same hurdles. Deca-BDE is one of the most studied chemicals and any replacement would suffer from the uncertainty that the precautionary principle says would lead to banning their use. For this reason, the precautionary principle is actually paralyzing. In all of the discussions of banning PBDEs it is assumed that they could be replaced, simply at a higher price. If the precautionary principle is consistently applied, however, these alternative chemicals would likely face the same fate as PBDEs. Of the 11 alternatives listed by Ecology in their report, all of them have less information about their toxicity than deca-BDE. That lack of information would leave them locked in limbo until the "proponent" could justify their use. Policymakers and regulators would find themselves in the uncomfortable position of wanting to maintain high standards of fire safety while blocking substances that could meet those standards.
Put simply, using the precautionary principle in decisions about banning PBDEs would leave regulators with an increasingly subjective decision and locked in a Catch-22 when deciding how to maintain fire safety standards while banning one of the most effective fire retardants available.
In their effort to ban deca-BDE, the Department of Ecology, the Department of Health and the Washington Toxics Coalition make some fundamental mistakes in their analysis of the potential health effects of deca-BDE. Understanding that the scientific case against deca-BDE is weak, they substitute impacts from other types of PBDE and from PCBs, making an unscientific leap of faith that is simply unsound when making public policy decisions.
Understanding this, they resort to a tactic which shifts the burden away from them and onto others by resorting to the "precautionary principle." The very fact that they make that attempt is an indication that they understand that they could not meet any reasonable scientific threshold. Even this, however, puts policymakers in a box.
Since none of the 11 alternatives identified by the Department of Ecology have anywhere near the level of study as deca-BDE, banning deca-BDE would leave policymakers with two options - allow another, lesser known compound to be used, violating the very precautionary principle they used to ban deca-BDE, or ban all of the listed alternatives and reduce fire safety standards, potentially increasing the risk of damage or death by fire. This is the ironic result of the efforts to ban deca-BDE.
Banning the most studied flame retardant simply on the basis that it may cause health impacts if levels dramatically increase, leaves policymakers in the position of incurring real risks by reducing fire safety.
Environmental activists in Europe and America have made attempts to ban deca-BDE. In each case, lawmakers have looked at the science and rejected those efforts. If Washington policymakers decide to ban deca-BDE, theywill not only run counter to the judgments of lawmakers across the world, but will put them in a position that will likely increase health threats to Washington residents.