Flame retardant chemicals, synthetic combinations of bromine and chlorine, are woven into crib mattresses, changing table pads, nursing pillows, and children’s clothing. They are present in strollers and car seats. They surround American newborns, collect beneath our toddlers’ fingernails, and represent the fibrous foundation of a $4 billion industry. The most well-known class of fire retardants, polybrominated diphenyl ethers or PBDE, are everywhere. And everywhere, worryingly, includes the growing bodies of our children.

Flame retardants, it turns out, have a nasty habit of leaching into the environment. They chip off your old furniture and taint the dust on your floor. They decay into cattle feed and persist all the way up the food chain, where they land on supermarket shelves in cartons of milk and fatty cuts of beef. The chemicals created and placed in our homes, on our furniture, in our children’s clothing — ostensibly to prevent fire and stay put — have gone feral. “Everyone is exposed to PBDEs,” says Ann Vuong, who studies the health impacts of PBDEs at the University of Cincinnati College of Medicine. “Everyone has levels of PBDEs in their bodies.”

That’s cause for concern, especially for parents. Mounting evidence suggests that flame retardants interfere with hormones and reproductive systems, stunting child development and harming fetuses. This data forces us to ask the question: is the trade-off between short-term safety and the potential for long term harm worth it? Even as federal and state governments ban the most worrisome chemicals (prompting manufacturers to introduce new and sometimes even less safe and less reliable alternatives) the answer seems to be no. Worse, these chemicals may not meaningfully retard flame. The trade-off may have never been between fire safety and biological harm — but between the suggestion of fire safety and the reality of risk.

“We need a better name for these chemicals,” says Tracy Woodruff of the University of California, San Francisco, an expert in how environmental chemicals impact early development. “After testing these flame retardant chemicals, it makes maybe a second-or-two difference [in time to combustion]. It’s not really meaningful when it comes to preventing the effects of a fire.”

A Brief History of Flame Retardants

The story of how we ended up with children’s items (and children) full of flame retardants begins in the early 1970s, when manufacturers began incorporating the flame retardant TDCPP (Tris(1,3-dichloro-2-propyl) phosphate) into kid’s pajamas and then, gradually, into furniture, mattresses, and other flammable items. They didn’t have much choice in the matter. Smoldering cigarettes had started thousands of deadly fires and, when lawmakers called upon Big Tobacco to create a flame retardant cigarette, they passed the buck. Textiles and furniture companies stepped up. If the cigarettes weren’t safe, at least the couch could be.

But concerns quickly mounted, with studies suggesting that this chemical could cause cancer, and TDCPPs were banned from children’s sleepwear in 1977 (although they still exist in other children’s products). Touted as safer alternatives, polybrominated biphenyls, or PBBs, appeared in the early 1980s. These chemicals, too, were banned after the manufacturer mislabeled a series of shipments and inadvertently supplemented the diets of thousands of Michigan cattle with brominated chemicals. Millions of people were exposed through meat before the mass culling of chemically-tainted cows that followed. The industry’s creative solution was to slightly alter the chemical structure of PBBs, with the addition of an ether group (an oxygen molecule connected to two carbon-hydrogen molecules). The contemporary PBDE was born.

For the next 25 years, PBDE was the flame retardant of choice; virtually every product that contained polyurethane foam came with a brominated chemical. PBDEs, too, were banned at the federal level in 2005, but their presence in the environment and in older consumer products continues to be a public health concern. “In 2010, more than 80 percent of the products we tested contained a flame retardant,” Heather Stapleton, who studies how flame retardants impact the environment at Duke University, told Fatherly. Fortunately, Stapleton says, progress has been made. “Our testing today suggests less than 20 percent of products contain a flame retardant.”

Today, the Environmental Protection Agency and the National Institutes of Health monitor new flame retardants and continue to gather studies on the adverse effects of older chemicals. And a dozen U.S. states regulate flame retardants to some degree, usually in children’s products. California, which once had some of the strictest laws in the country requiring consumer items to contain flame retardants, recently signed a bill that will all but ban these chemicals from furniture, children’s products, and mattresses.

But PBDE flame retardants persist — and they’re still inside of us, too. One 2018 study of 334 mother-child pairs found the chemical present in every child tested. “You can get exposed through old furniture and also through food, especially if you eat a high-fat diet, because these chemicals tend to accumulate in fat and then bioaccumulate up the food chain,” Woodruff says, explaining that if PBDEs end up in a cow’s food supply, for instance, they enter our guts when we eat beef or drink milk. “It’s in dust, too, and kids crawl around in the dust, put their hands in their mouths. They’ll have higher exposures because of that.”

The Potential Dangers of PBDEs

Most flame retardants are structurally similar to thyroid hormone chemicals, and can easily interact with the thyroid hormone. Studies have found strong associations between exposure to flame retardants and thyroid disorders, as well as poor performance on neurodevelopmental tests and reductions in fertility. “There is concern about effects on the developing brain — similar to concerns related to lead exposure,” Stapleton says.

Reiko Kishi and colleagues at the Hokkaido University Center for Environmental and Health Sciences in Japan have been at the forefront of studying how the phosphate-based flame retardants TDCIPP, TCIPP, and TNBP may impact children’s health, specifically when it comes to asthma and allergies. “We found significant associations between increasing levels of TDCIPP and TCIPP in house dust and increased risk of atopic dermatitis, as well as increased levels of TNBP and asthma,” Kishi told Fatherly. In a separate study, Kishi and colleagues also found a link between TDCIPP in dust and allergies and eczema in children.

That’s particularly disappointing because phosphate-based flame retardants have long been touted as safer alternatives to PBDEs and other bromine-based chemicals. “Because of their endocrine disrupting effect and bioaccumulation, brominated flame retardants were phased out, and phosphate flame retardants have been used as alternatives,” Kishi says. “But there is little awareness of the potentially harmful effects of phosphate flame retardants among the general population.”

Not that there appears to be any safe flame retardant on the market. Other work has linked a variety of flame retardant chemicals to infertility in women and decreases in male reproductive hormone. And there’s a strong correlation between PBDE exposure in childhood (even in the womb) and poor cognitive development. “Epidemiological studies have provided evidence that PBDEs are neurotoxicants,” Vuong says, citing reports of “decreased full-scale IQ, impairments in executive function, and more hyperactivity and aggression problems in children who were exposed to higher PBDE levels during gestational development.”

Indeed, one recent study by Woodruff of nearly 3,000 mother-child pairs, found that every 10-fold increase in a mother’s PBDE levels corresponded to a drop of 3.7 IQ points in her child.“We do not yet know whether these fears are an overreaction,” Kishi says. “But this could be a widespread problem. Better to avoid unnecessary usage of materials with flame retardants.”

Do Fire Retardants Actually Retard Fire?

Whether flame retardants actually prevent fires and save lives is a subject of fierce controversy. On one hand, the American Chemistry Council and other industry groups maintain that flame retardants are necessary and effective. “Without flame retardants, the time of flashover occurs in three minutes or less and, if you’re trapped in an airplane or in a house, you have only three minutes to escape,” American University’s Douglas Fox says in a video for the ACC’s North American Flame Retardant Alliance. “The purpose of flame retardants is that it delays that. You now have 10 to 15 minutes to get out.”

Harvard University’s Joseph Allen disagrees. “One of the misnomers about flame retardants is that they actually provide a fire safety benefit. Everything that I have read and seen indicates that they really don’t,” he says in a video for Harvard’s Sustainability mini-site. “I have been working with the FAA on this. [Flame retardants are] used in just about every component of airplanes, and the fire safety experts there say they don’t do anything against the type of fires that are typically encountered on an airplane. I have seen the same kind of reports for the fires that are typical in our homes. They don’t really work.”

Woodruff provides some population-level evidence to support Allen’s claims. “California had a strong flame retardant standard [requiring products to contain these chemicals] but didn’t have any fewer deaths because of it,” she says. “This was not preventing fire deaths in California.”

Flame retardant chemicals may even make some fires worse. “The presence of flame retardants in these products results in the production of hazardous chemicals in the air when they do burn, including carbon monoxide, soot, and hydrogen cyanide,” Stapleton adds.

Besides, even if the ACC and industry groups are correct that flame retardants are somewhat effective, it is unclear what they’re doing in products that seldom catch fire — especially given the evidence of their negative health effects. “Most children’s products, like nursing pillows and changing table pads, are not fire risks,” Stapleton says. “The data does not suggest that these are products are ignition sources in home fires.”

Flame Retardants and Fire Safety for Kids

Since flame retardant chemicals are often found in dust around the home, the simplest steps parents can take to cut down exposure is mopping and vacuuming regularly (sweeping just moves the dust around), ensuring that all family members wash their hands before they eat, and checking labels before buying mattresses and car seats. In many cases, manufacturers are proud to clarify that they do not use flame retardants. If you are particularly concerned, Duke University offers a free testing service to detect flame retardants in furniture.

But there’s a limit to what parents can do to cut down on the family’s exposure. A lot of it is a waiting game. In time, as flame retardants are phased out and the environment heals, we’ll see fewer and fewer chemicals in our food supply and dust. Until then, Woodruff suggests parents temper their flame retardant fears, if only a little.

“As a parent, it’s really frustrating — people have a right to be angry about flame retardants,” she says. “We have a lot of problems we’re dealing with. Wooden toys versus plastic…it’s overwhelming. You work in this field, and it does feel like every time you turn around you’re saying ‘Oh, that chemical is bad’. But we do have a problem and, at the same time, kids are generally healthy and there are a lot of things you can do to help them be resilient. What’s the right level of concern? I don’t know. Every parent has to decide that for themselves.”

As for your family’s fire safety? Smoke detectors, fire extinguishers, and a fire safety plan are all crucial — and all a family can really do to prevent fire accidents. A working smoke detector alone can halve the chances of death for a family in a fire.

The Moral of the Fire Retardant Story

Consider the household cat. This friendly feline has been introduced all over the world as a means of catching rats and mice. Since becoming a global species, felis catus, has also hunted literally hundreds of species to extinction, disrupting ecosystems around the world. Flame retardants are, in some ways, the cats of the chemical world. They were brought in to solve a clear problem—cigarettes causing house fires, and airplanes burning up in the sky—but the unintended consequences have been nothing short of horrific.

Why were American parents so quick to allow chemicals they didn’t understand into their homes, and why were manufacturers so quick to start weaving them into pajamas? The answer is relatively simple: flame retardants replaced a visceral problem with a complex one, and an immediate problem with a long-term one. Humans, possessed of Pleistocene brains and living in an Anthropocene world, are wired to react. We tend to default to short-term thinking, specifically in situations of danger. Give a parent a fireproof pair of pajamas for their kids—or a cat that solves a pesky mouse problem—and they’ll seldom ask any questions.

The fire retardant saga, if nothing else beyond a health hazard, is an object lesson in the need to find direct solutions to public health concerns. Complexity can be a solution but, in a world where even fabrics are hard to understand, inconvenient or unpleasant simplicity is probably the way to go. And parents

This article was originally published on Feb. 5, 2019