This is the third article in a three-part series by investigative reporter Liza Gross, exploring the most dangerous toxins found in the average American home. The stories track fertility, pregnancy and, now, early childhood development.
Heather Stapleton vividly recalled the moment she realized that the dangerous chemicals she studied in her lab had entered her home.
Dr. Stapleton, a chemist at Duke University, had just put her 1-year-old son to bed and was chatting with a colleague in her living room about their latest research. The scientists were talking about the toxic chemicals they’d found in baby gear, added to prevent them from catching on fire. Suddenly, they noticed a tag on her son’s polyester tunnel. “We’re like, wait,” Dr. Stapleton said. “Is that a flammability standard on the tunnel?”
Sure enough, the tunnel’s tag said that it met a flammability standard for camping tents, meaning that the material contained chemical flame retardants that would prevent it from catching — and staying — on fire.
So Dr. Stapleton did what any new mother with access to a state of the art chemistry lab and a $120,000 sample analyzer would do. She cut a snippet of the tent and brought it back to her lab for analysis. She was shocked by what she found on the fabric: a flame retardant, called chlorinated tris, that manufacturers had voluntarily removed from baby pajamas decades earlier after researchers showed it could alter DNA, and likely cause cancer, in test tubes.
“That really horrified me,” she said, recalling how her son, Joshua, loved to play peekaboo through the tunnel’s mesh windows. “He put his mouth all over that mesh.”
Flame retardants are chemicals that manufacturers started adding to commercial and consumer products in the 1970s to meet flammability standards. While not all of the hundreds of flame retardants on the market present health risks, scientists have raised concerns about formulations that contain chlorine, bromine or phosphorous. Flame retardants are typically added to goods with the potential to ignite, like upholstered furniture, baby products, electronics, building and construction materials, clothing, car seats and vehicle interiors. The chemicals can escape from treated products and penetrate the skin or accumulate in dust, which kids can get on their hands and put in their mouths.
Extensive research in lab animals has linked different flame retardants to various health problems. Brominated flame retardants, which have received the most scrutiny, can build up in tissue, cause cancer, disrupt hormones, harm the reproductive system and cause neurodevelopmental problems, at least in animals and perhaps humans too. Studies in people are limited, largely because they require far more time and resources, but have found similar effects, including increased risk of cancer, lower I.Q. and possibly behavioral problems in young children, including hyperactivity, aggression and bullying. Earlier this year, researchers reported that brominated flame retardants surpassed lead as the biggest contributor to I.Q. loss and intellectual disability in children.
So how did they end up in Joshua’s toy? Flame retardants, like many toxic chemicals, are loosely regulated. Manufacturers aren’t required to prove that they’re safe or even that they keep products from going up in flames. Although researchers have linked numerous flame retardants to serious health effects, federal regulators never banned their use in all products. So when manufacturers agree to stop using flame retardants in one product, like baby pajamas, they just find other uses for them — or switch to similar chemicals that scientists haven’t evaluated yet.
“I call it the chemical conveyor belt,” Dr. Stapleton said. “They just keep coming.”
There is also no reason these chemicals should be in many products in the first place. There is no rule requiring flame retardants to be in children’s toy tents, said Patty Davis, a spokeswoman for the U.S. Consumer Product Safety Commission, which regulates consumer products.
But Dr. Stapleton wasn’t about to wait for regulatory action. So she dedicated her career to figuring out what other products might expose kids to these dangerous chemicals. Luckily, she had plenty of collaborators around the country to help her sift through the dizzying alphabet soup of industrial flame retardants, including the chemist who first sounded the alarm about their risks.
The chemical conveyor belt.
In 1977, Arlene Blum, then a chemist at the University of California, Berkeley, was the first to show that brominated tris, a flame retardant in children’s pajamas, gets into kids’ bodies and might cause cancer. Regulators quickly banned the chemical from pajamas. But manufacturers just switched to its chemical cousin, chlorinated tris — the flame retardant Dr. Stapleton found in Joshua’s tunnel. The next year Dr. Blum showed that the replacement had “virtually the same” chemical structure and potential to cause cancer.
These days, Dr. Stapleton and Dr. Blum, who now runs the nonprofit Green Science Policy Institute, often collaborate as chemical detectives.
It’s a daunting task. They can’t simply ask companies that make car seats, play tunnels or other kids’ products which flame retardants are included, because most have no idea. It’s nearly impossible to track a chemical from the time it’s made to when it’s added to components that are then incorporated into consumer products.
So they must determine which of the scores of kids’ products have flammability standards, and which of the hundreds of chemicals on the constantly changing $7 billion flame retardant market might be used.
Back in 2009, when Dr. Stapleton analyzed foam from her son’s nursing pillow and other baby products, she flagged two flame retardants had not been publicly identified before.
After that, she asked colleagues to donate foam from car seats, strollers, nursing pillows and other baby products. Her study, published in 2011, found flame retardants in 80 percent of more than 100 tested products, including all car seats. The next year, she found flame retardants in 85 percent of more than 100 couches tested, revealing the family sofa as a major source of exposure.
The most commonly detected flame retardant in both baby products and couches was chlorinated tris. Manufacturers agreed to remove it from kids’ pajamas more than 40 years ago, but it keeps coming back, like Batman reboots.
Dr. Stapleton’s papers made national headlines and caught the attention of California regulators. They’d recently removed a few baby products — nursing pillows, infant carriers and strollers — from their flammability regulation. Dr. Stapleton’s work persuaded regulators to exempt more than a dozen baby products from fire-safety rules.
“It was the one time I felt like our research was directly related to policy change,” she said.
But there’s always another chemical on the conveyor belt and another product to put it in. For instance, car seats are loaded with flame retardants to meet the same federal motor flammability standards as the cars they’re strapped into. But since most car fires start in the engine, Blum said, flame retardants won’t help once a fire reaches the passenger compartment.
Blum worries kids who eat in their car seats may get a helping of flame retardants with their Cheerios.
Jennifer Garfinkel, a spokeswoman for the American Chemistry Council, a chemical industry trade group, defended the use of flame retardants in car seats. “Maintaining fire safety in vehicles is essential,” she wrote in an email, “and flame retardants are an appropriate method to improve fire safety in such applications, pursuant to the federal government’s flammability requirements.”
Car seat manufacturers with naturally fire-resistant materials, like wool, can cost twice as much as chemically treated seats. Even without a car seat, passenger seat foam typically contains high levels of chemicals like chlorinated tris, Dr. Stapleton said.
Less stuff, lower exposures.
In 2017, Dr. Stapleton reported that toddlers’ urine had 15 times higher flame retardant concentrations than their mothers’, perhaps from crawling on the floor before sucking on their hands. In October, her team published a study that found that urine concentrations of one type of flame retardant increased along with the number of baby products at home. “It suggests that if you bought a ton of stuff, there’s more exposure to the kids,” Dr. Stapleton said.
The study measured only exposures, not health effects. But finding high levels of these toxic chemicals in babies as young as 6 weeks old, when immune and neurological systems are still developing, is worrisome, the authors noted. Since children are mostly exposed through house dust, experts recommend using a vacuum with a HEPA filter and washing kids’ hands frequently.
The evidence regulators require to ban a substance seems to grow every year, Dr. Stapleton said. And they still evaluate the risk for one chemical at a time, even though people are exposed to multiple chemicals simultaneously. “It’s very challenging to characterize those exposures,” she said. “But we need to start moving in that direction.”
Dr. Blum has been urging regulators to think about harmful chemicals as members of a class. “The solution isn’t another chemical, but a different way of designing a product or a different regulation,” she said.
For instance, California regulators have changed their standard to focus on the outer fabrics of furniture, rather than the bulky foam, which has led to a substantial reduction of toxic flame retardants.
Dr. Stapleton has turned her attention to trampoline parks and obstacle courses courses that have pits with foam cubes, which are also treated with flame retardants. Kids emerge from those pits sweaty and covered in dust and debris from the foam, so parents should make sure kids bathe when they get home. She also offers free testing of foam samples to ease parents’ minds.
But ultimately, Dr. Stapleton said, parents seeking peace of mind shouldn’t have to rely on scientists who spend millions of taxpayer dollars in a losing battle with the conveyor belt.
“It might be better public health policy,” Dr. Stapleton told a Senate committee in 2012, “to rigorously examine the safety of these compounds before they are put into the products found in the homes of millions of Americans.”
Liza Gross is a science and health journalist and author of “The Science Writers’ Investigative Reporting Handbook.”