The Case Against Chemical Flame Retardants
Polybrominated diphenyl ether (PBDE) flame-retardants were recently shown to be present at very high levels in the blood and house dust of Californians, possibly because of a unique Californian law that requires furniture to be flame-resistant. These chemicals are garnering much interest as of late because of their <a href=“http://www.clinmedres.org/cgi/content/full/1/4/281?maxtoshow=&HITS=&hits=&RESULTFORMAT=&fulltext=toxic+furniture&andorexactfulltext=and&searchid=1135724264866_17116&FIRSTINDEX=0&resourcetype=1” target’_blank">potential toxic health effects on humans. What are PBDEs, and why might they be toxic?
There are 209 different PBDE varieties, also called congeners. They are identical in molecular structure except that the number and/or position of bromine atoms in each congener vary. One of these congeners, pentabrominated diphenyl ether (penta), is a mixture containing congeners with four, five, and six bromine atoms. It was used extensively in polyurethane foam.
The manufacture of penta was banned by the European Union in 2003 and by the U.S. in 2004 because of increasing evidence of the congener’s toxicity in humans and other organisms. However, no import restrictions exist on products containing penta. Other countries can manufacture penta, add it to consumer products and sell those products in America.
Penta and other PBDEs accumulate in fatty tissues in animals of all kinds and can be passed from mother to child via breast milk. Even though penta was banned in the U.S, it is still present in homes, animals, humans and the environment because of its prevalence in furniture bought before the ban; its use in imported furniture and its apparent resistance to degradation. Other PBDE varieties such as octa and deca, used in plastic electronics casings such as for televisions, volatilize out of the plastic and into the air. They are banned in several states because they have been shown to cause liver toxicity, disrupt reproductive systems and cause endocrine disruption.
PBDEs sound like bad actors, but once upon a time they were the good guys. They replaced polychlorinated biphenyl (PCB) flame-retardants, which were banned by the United States Congress in 1976. PCBs, like PBDEs, are incredibly persistent: 30 years after the ban, PCBs are still found ubiquitously in mammals, human blood and umbilical cords, fish, birds, air, soil, lakes, rivers, house dust, sewage and wastewater sludge.