PBDE (polybrominated diphenyl ethers)
Flame retardants are used in everyday items (from computer casings to carpet pads to foam cushions in chairs and couches) to reduce their ability to catch fire. In recent years, however, the three widely used flame retardants called PBDEs (polybrominated diphenyl ethers) have been detected in people’s bodies. Scientists have learned that:
- PBDEs steadily migrate from the items to which they were added and build up in the fat tissue of living organisms, such as people and animals.
- Some PBDEs used as flame retardants have been linked to brain and thyroid problems in laboratory rodents.
- The levels of PBDEs in people’s bodies are doubling every 2 to 5 years, and are 40 times higher in North America than on other continents. If this rate continues, the levels in humans could reach those known to cause problems in laboratory rodents. Frequently Asked Questions about PBDE Flame Retardants
Q: What are PBDEs?
A: For years, manufacturers have used chemical additives to reduce the flammability of everyday items, from computer casings to carpet pads to foam cushions in chairs and couches. Some of the more widely used of these additives are polybrominated diphenyl ethers, or PBDEs.
Q: Why should I be concerned about PBDEs?
A: In recent years, scientists have discovered that:
- PBDEs leach out of the items to which they were added and enter the environment. PBDEs are showing up in the air, soil and sediment, and are building up in animals throughout the food chain.
- PBDEs travel great distances and have been detected in remote regions, turning up even in the bodies of polar bears in the Arctic. PBDEs are being found in everything from meat and dairy products to fruits and vegetables as well as indoor air and household dust. And because some PBDEs don’t break down easily, the levels of PBDEs in the environment are steadily rising.
- In lab tests with rodents, some PBDEs have been linked to problems in brain development and thyroid hormones. Most of these problems stem from pre-natal exposure and exposure soon after birth. The health effects appear to be permanent.
- PBDE levels in humans are about 10 to 100 times higher in the U.S., the world’s largest producer and consumer of PBDEs, than in Europe. Scientists say North American levels appear to be rising at an exponential rate, doubling every two to five years, while countries that have banned their use have seen levels decrease.
- U.S. levels of PBDEs are rising. Studies have found them in human blood, fat and breast milk. Breast-feeding appears to overcome some of the effects of harmful chemicals and remains the healthiest way to feed babies.
Q: How do PBDEs work?
A: PBDEs are blended into plastics and foams during the manufacturing process. Later, if objects containing PBDEs reach extremely hot temperatures, they release atoms called bromines that rob the air of the oxygen needed to start or feed a fire.
Q: What kinds of products contain PBDEs?
A: The three commercially produced mixtures of PBDEs are Penta-BDE, Octa-BDE and Deca-BDE. Different types of PBDEs are used in different products:
- Penta-BDE is used primarily in foam products such as seat cushions and other household upholstered furniture as well as in rigid insulation.
- Octa-BDE is used in high-impact plastic products, such as housings for FAX machines and computers, automobile trim, telephone handsets and kitchen appliance casings.
- Deca-BDE is used in plastics, such as wire and cable insulation, adhesives, coatings and textile coatings. Typical end products include housing for television sets, computers, stereos and other electronics and audiotape cassettes. Deca-BDE also is used as a fabric treatment and coating on carpets and draperies. Deca-BDE is not used in clothing.
Q: How do PBDEs make their way into my body?
A: Scientists aren’t sure. The presence of PBDEs in living organisms became apparent only in recent years, and the sources have only begun to be studied. Likely avenues include dust, air and food.
Q: Are PBDEs harmful?
A: Although PBDE levels in humans haven’t reached the levels that cause problems in lab animals, scientists are concerned because the levels in humans keep rising. Penta-BDE and Octa-BDE have been shown to cause brain and thyroid problems in rodents. Deca-PBE appears to be less toxic than Penta-BDE and Octa-BDE, but may break down to more toxic forms of PBDEs in the environment. This is an area of ongoing study.
Q: Why have PBDE flame retardants been allowed in products if they may be harmful?
A: Penta-BDE and octa-BDE were discovered to be harmful to mice in lab tests only in recent years; the sole U.S. producer of penta-BDE and octa-BDE has voluntarily agreed to stop producing and selling them by the end of 2004 and 2005 respectively. The continued use of deca-BDE, meanwhile, may depend on the results of current or future studies. Laboratory studies show that deca-BDE can break down into penta-BDE and octa-BDE over time, so even if deca-BDE is safe in its original state, it would nevertheless be a source of harmful PBDEs if breakdown occurs in real-world conditions. Some businesses have voluntarily stopped using deca, while other businesses believe deca should continue to be used unless or until ongoing studies prove it to be harmful to humans.
Q: Are there alternatives to PBDEs?
A: The three basic flame-retardant alternatives to using PBDEs are:
- Substituting non-brominated chemical additives.
- Substituting materials that don’t require PBDEs.
- Changing the design and construction of products so they are inherently less flammable.
Q: Why don’t companies just stop using PBDEs?
A: Some have. Many manufacturers have discontinued using penta-BDE and octa-BDE, and others will be unable to use them once production ends in 2004 and existing stockpiles run out. Some manufacturers such as Apple, Dell, Sony and Xerox have voluntarily stopped using deca-BDE. Sweden has phased out deca-BDE products altogether; IKEA uses no PBDEs in its products. Other manufacturers say they have not found adequate alternatives for their particular applications, or that it is unnecessary to discontinue using deca-BDE because it has not been proved to harm humans.
Q: Is there any way to keep PBDEs out of my body?
A: Scientists are still trying to identify the most likely ways that PBDEs enter our bodies – whether through food, drinking water, the air we breathe, if they are absorbed through our skin, or some combination of these. We need these answers in order to know how to guard against PBDEs.
Q: How are workers exposed to PBDEs?
A: There is very little information about workplace exposure to PBDEs. Studies from Sweden suggest that workers may be exposed to PBDEs in computers and electronics. One study showed that workers who dismantle and discard electronics at a recycling plant are exposed to PBDEs. PBDE exposure was also found in computer technicians, although at lower levels than for those in the recycling plant. The source of the exposure is thought to be dust from plastic components.
Q: How can exposure to PBDEs be reduced in the workplace?
A: Reducing the amount of PBDE-containing dust in the workplace appears to reduce worker exposure. In the Swedish electronics recycling plant, exposure was reduced when the shredder was moved away from the workers, the ventilation system was upgraded and cleaning procedures were improved.
Q: What is the Department of Ecology doing about PBDEs?
A: In January 2004, Gov. Gary Locke directed Ecology, in coordination with the Department of Health, to draft a plan to manage PBDEs. Ecology assembled an advisory committee of representatives from a wide spectrum of perspectives – from makers of PBDE products to businesses that dispose of them, from health groups to physicians and scientists – to provide information and perspectives on possible policy recommendations. On Jan. 5, 2005, Ecology and Health presented the governor with an interim plan that calls for a general ban on the use of Penta-BDE and Octa-BDE and recommends that Ecology and Health research and develop a ban on Deca-BDE products.
Q: Why wait? Why not ban Deca-BDE now, along with Penta-BDE and Octa-BDE?
A: Last year’s focus on an overall PBDE plan didn’t leave Ecology and Health enough time to research a number of factors that would be involved in banning Deca-BDE. More research is required if the agencies are to develop a ban that is practical and effective.
Q: What will happen next?
A: Some things Ecology and Health can address within existing programs. Other recommendations may require a change in state law and/or funding, in which case it is up to the Legislature to take the next step.
For more information visit Washington State Department of Ecology’s PBDE flame retardants: A fast-growing concern.