Over the past 40 years, a class of chemicals with the tongue-twisting name of halogenated flame retardants has permeated the lives of people throughout the industrialized world. These synthetic chemicals — used in electronics, upholstery, carpets, textiles, insulation, vehicle and airplane parts, children’s clothes and strollers, and many other products — have proven very effective at making petroleum-based materials resist fire.
Yet many of these compounds have also turned out to be environmentally mobile and persistent — turning up in food and household dust — and are now so ubiquitous that levels of the chemicals in the blood of North Americans appear to have been doubling every two to five years for the past several decades.
Acting on growing evidence that these flame retardants can accumulate in people and cause adverse health effects — interfering with hormones, reproductive systems, thyroid and metabolic function, and neurological development in infants and children — the federal government and various
Compounds thought to be off the market due to health concerns continue to be used in the U.S.states have limited or banned the use of some of these chemicals, as have other countries. Several are restricted by the Stockholm Convention on persistent organic pollutants. Many individual companies have voluntarily discontinued production and use of these compounds. Yet despite these restrictions, evidence has emerged in recent months that efforts to curtail the use of such flame retardants — a $4 billion-a-year industry globally — and to limit their impacts on human health may not be succeeding.
This spring and summer, a test of consumer products, as well as a study in Environmental Science & Technology, showed that use of these chemicals continues to be widespread and that compounds thought to be off the market due to health concerns continue to be used in the U.S., including in children’s products such as crib mattresses, changing table pads, nursing pillows, and car seats. Also this summer, new research provided the first strong evidence that maternal exposure to a widely used type of flame retardant, known as PBDEs (polybrominated diphenyl ethers), can alter thyroid function in pregnant women and children, result in low birth weights, and impair neurological development.
“Of most concern are developmental and reproductive effects and early life exposures — in utero, infantile and for children,” Linda Birnbaum, director of the National Institute of Environmental Health Sciences and the National Toxicology Program, said in an interview.
Heather Stapleton, assistant professor of environmental chemistry at Duke University and lead author of the recent Environmental Science & Technology study, said more action from industry and government
Many infants are in physical contact with products treated with these chemicals 24 hours a day.regulators is urgently needed. “My concern is the elevated exposure infants and toddlers are receiving,” Stapleton said in an email. “A high proportion of infants are in physical contact with products treated with these chemicals almost 24 hours a day. Some of these chemicals are either known or suspected carcinogens. During the first year of life, infants are still developing, particularly their brain. And some of these flame retardant chemicals have chemical structures similar to known developmental neurotoxicants (e.g. organophosphate pesticides).”
In one study, published this summer in the American Journal of Epidemiology, University of California, Berkeley researchers found that each ten-fold increase in levels of various brominated flame retardants in a mother’s blood was associated with an approximately 115 gram decrease in her baby’s birth weight, a drop the researchers describe as “relatively large.”
“What makes this significant, is that this is the first long study that suggests maternal exposure to PBDEs may impact fetal development and health,” explained lead author Kim Harley, associate director for health effects at the University of California, Berkeley, Center for Environmental Research and Children’s Health.
As evidence linking the use of halogenated flame retardants to health risks continues to mount, there is increasing pressure on government and industry to take action. About a dozen U.S. states have enacted laws that bar certain uses of various flame retardants. Among these regulations are those that bar the use of two or more polybrominated diphenyl ethers
Flame retardants are still found in products from which they have been barred, probably due to poor oversight of supply chains.(PBDEs), particularly in children’s products. New York recently passed a law limiting use of the flame retardant known as Tris, while the European Union limits the use of certain halogenated flame retardants in electronics — a regulation that most companies comply with worldwide. The U.S. Consumer Product Safety Commission barred Tris from children’s clothing in 1977 after it was identified as a carcinogen and a mutagen. And using its authority under the Toxic Substances Control Act, the U.S. Environmental Protection Agency (EPA) and PBDE manufacturers have worked out a voluntary phase-out of these compounds that began in 2004 and is to conclude in 2013.
Yet new halogenated flame retardants with chemical compositions and structures similar to those that are now regulated, including PBDEs, continue to enter the market. (This class of compounds typically uses bromine and chlorine, elements known as halogens, to inhibit combustion.) Meanwhile, those that are restricted are being found in products from which they’ve been barred, most likely due to various flaws in supply-chain oversight. At the same time, older products containing discontinued flame retardants remain in use; many of these products — furniture, carpeting, car seats, and strollers, for example — are designed to last for years, prolonging exposure to chemicals with documented adverse health effects. But tracking the use of individual flame retardants is challenging, as product labels are not required to declare these substances, nor are chemical manufacturers required to reveal full details of what goes into their products.
The American Chemistry Council (ACC) and other chemical industry groups maintain the safety of currently manufactured flame retardants, and the ACC says that in the U.S. each year flame retardants prevent 360 deaths and 740 injuries that would have resulted from furniture fires alone.
So how can use of these compounds be reduced or eliminated?
The EPA is in the process of assessing potential alternatives to PBDEs and other flame retardants. But a list of potential alternatives released last month includes numerous other halogenated compounds, and many chemicals on the list will likely fail to meet the program’s health-safety goals.
Some experts say what is sorely needed is for industry to begin relying less on the highly flammable, petroleum-based materials used in so many consumer products. “It’s essential that we rethink the base materials we
‘I don’t question the need for flame retardants in airplanes, but do we need them in baby strollers?’ asked one expert.use to make products,” said Kathy Curtis, policy director of Clean New York, a non-profit organization advocating for chemical safety. “Styrene insulation is so flammable that flame retardants are required, and they still burn quite easily. Polyurethane foam in furniture and baby care products is also highly flammable, despite the added flame retardants certain flammability standards require. We have to stop using such fuel-rich, petroleum-based materials in buildings when safer, inherently flame-retardant substitutes are available for these same uses.”
John Warner, president of the Warner Babcock Institute for Green Chemistry, said that industry has become so reliant on flame retardants that as much as a third of the weight of plastics used in airplanes comes from one type of PBDE flame retardant, known as “deca.” Finding an alternative will be challenging, said Warner, especially since from a fire-safety point of view deca is “tried and true,” and it is used in so many different types of plastics and foams. There are viable non-toxic alternatives to using halogenated flame retardants, Warner explained, but thus far, not one that will work as a drop-in substitute for all uses of deca.
Two companies that manufacture children’s products are working to eliminate the need for flame-retardant chemicals by using fabrics whose density and composition enable them to meet flammability standards without chemical additives. Joseph Hei, president and founder of OrbitBaby, said his company has commissioned the milling of its own patented, organic cotton-wool blend fabrics that are fire-resistant. The safety of the products is certified to the Oeko-Tex 100 standard, administered by the Zurich-based Oeko-Tex Institute, which conducts tests to ensure the safety of textiles. “We verify and do our own follow-up screening of these fabrics,” Hei said in an interview.
Andreas Zandren, vice-president for sales, marketing, and product development for BabyBjorn, said his company has found a similar solution by using a densely woven cotton in some products and thinner foams that don’t require use of flame retardants. BabyBjorn does in-house testing of all fabrics to make sure they are free of hazardous flame retardants, Zandren said.
Hei explained that there are relatively few mills that offer Oeko-Tex certified fabrics, adding, “It’s a sourcing challenge.” Both companies also acknowledged that meeting California’s tough flammability standards and U.S. car flammability regulations is challenging. But, said Zandren, “Strict standards challenge us to be very creative in sourcing and testing new materials, as well as creating smart designs.”
MORE FROM YALE e360
Eventually, product redesign that avoids flammable materials will be key, experts said.
“I think we should be asking, ‘Where do we really need them?’” said Linda Birnbaum of the National Institute of Environmental Health Sciences. “I don’t question the need for flame retardants in an airplane, but do we need them in nursing pillows and babies’ strollers? Are we putting chemicals in places we don’t need them?”