Real Science for Real PeopleBrominated Flame Retardants
- The Next PCBs? By Beth Ravit
However, for many of the same reasons that they are useful, these compounds have also proven to be very dangerous to human health and they are now turning up in sewage sludge, our streams and estuaries, and human bodies, including in mothers’ breast milk. Halogenated organic compounds are formed through the addition of halogen atoms (fluorine, chlorine, bromine, iodine) to a compound containing carbon atoms. The resulting chemical entities tend to be hydrophobic (“water hating”). Many are tolerant of high degrees of heat. They are relatively non-reactive and tend to bioaccumlate in the food chain. One of the most widely used groups of halogenated organics was PCBs, and the banning of these substances in 1979 has resulted in the development of brominated compounds to replace the banned substances. Scientific studies of PBDEs, the majority of which have been done in Europe, have linked these chemicals to both reproductive and brain problems. Abnormalities in offspring of exposed animals suggest exposure to PBDEs may cause genetic damage. The liver, immune, nervous and endocrine systems have also been shown to be affected by PBDEs. Many studies have focused on the impact to developing embryos, and concentrations of PBDEs in umbilical cord blood have been found to be identical to those of the mother. Dr. Ronald Hites calls this the “ultimate Bambi factor,” when we expose the youngest and most vulnerable members of our society (unborn babies) to toxicity. There are scientists who are now arguing for a ban on PBDEs and the initiation of a global phase out, calling these compounds the next PCBs. The European Union has banned two of the three most popular PBDE compounds beginning in 2004, and California has passed a law that will take effect in 2008 banning two PBDE mixes. Some manufacturers (Toshiba, Sony, Fujitsu) have announced a phase out of PBDEs from their products, and IKEA, the Swedish furniture retailer, has eliminated brominated flame retardants from its products. In November 2003, the Great Lakes Chemical Corp. announced that it would voluntarily stop producing two widely-used flame retardant chemicals by the end of 2004. In spite of these actions by responsible companies, the United States Environmental Protection Agency (EPA) has not concluded that PBDEs pose an unreasonable risk to human health or the environment, and currently does not believe there is a need to remove or replace products that contain these chemicals. EPA is in the process of assessing the current scientific studies in the hope of gaining a better understanding of brominated flame retardants. We hope that EPA will learn from the PCB legacy they are now trying to correct and move quickly to protect our waterways from this newest source of contamination. Author’s Note: I would very much like to hear your comments, concerns and questions about Real Science for Real People. You can contact me via email at: bravit@eden.rutgers.edu. I look forward to hearing from our readers. |
We use them every day in computer circuit boards, plastic
housing for office equipment, rubber cables, paints, plastic electrical parts,
fabric backing, foams (including mattress foam), resins, cable coatings,
imitation wood and carpet padding. For three decades, manufacturers have been
adding brominated compounds to these products because of their ability to
prevent and retard fire hazards. Now, 25 years after the phase-out of PCBs,
scientists are finding a new form of contamination – a class of halogenated
flame retardants called polybrominated diphenyl ether (PBDE). The chemical
structure of PBDEs is very similar to that of PCBs – a double ring structure –
with up to 10 bromine atoms attached (See Hackensack Tidelines, Spring 2001).
Yearly production of PBDEs exceeds 200,000 metric tons, 25% of which – over
50,000 metric tons – is consumed in the U.S. annually.