A new study has found that flame retardants—used in everything from furniture to baby toys—are increasingly showing up in people’s bodies, raising potential health concerns.

Research led by Duke University shows that two flame-retardant chemicals, which belong to a class of flame retardants called organophosphates, not only were found in the urine of most of the 857 adults and children tested but also rose steadily in samples collected between 2002 and 2015.

This is not the first time organophosphates have been found in people. But this is the first study to find that the levels in Americans increased over a long period.

“We know from animal testing that there are a variety of toxic outcomes associated with exposure to these chemicals at high concentrations,” says Heather M. Stapleton, Ph.D., an associate professor of environmental ethics and sustainable environmental management at Duke University and one of the study authors. 

Pros and Cons of Flame Retardants

Flame retardants are used in products to stop or slow the spread of fire. They’re found in a number of different products including car seats, upholstered furniture, TVs, computers, clothing, baby toys, nursing pillows, and plastics used to make food containers. For some of these products, manufacturers use flame retardants to help them meet required federal or state flammability standards—though some evidence suggests not all products with flame retardants need them to meet such standards.

Though reducing combustibility of household goods is important, some flame retardants leech out of the products and into the environment, and can be absorbed into the body through the skin, through inhalation, or by swallowing. Not all flame retardants are harmful, but some, including organophosphates, are known to cause adverse health effects, with human and animal studies linking them to cancer, hormonal changes, and fertility problems.

In 2004, such concerns led to one of the most commonly used flame-retardant mixtures, called pentaBDE, being voluntarily phased out after it was linked to health problems and was detected in alarming levels in people’s bodies. Many manufacturers began to use organophosphates in their place.

More than 90 percent of the 857 adults and children in the Duke-led study had two commonly used organophosphates, TDCIPP and TPHP, in their urine. On average, the levels of one of the chemicals, TDCIPP, were 17 times higher in adults in 2015 than they were in 2002.

The results of the Duke-led study indicate that organophosphates are following the same pattern as pentaBDE. “Scientists knew that exposure to pentaBDE was going up, so we phased them out,” Stapleton says. “Now, organophosphates are going up as well. We need to understand more about their health risks and at what level these chemicals become harmful.” 

Are Flame Retardants Necessary?

The two organophosphates found in increasing levels in the study are of particular concern. Manufacturers phased TDCIPP out of use in children’s pajamas in 1977 when scientists linked the chemical to cancer in animal studies. Animal studies have also suggested that TDCIPP might alter the regulation of the body’s hormones, specifically thyroid hormone, and both TDCIPP and TPHP might cause fertility problems.

“We’ve known that TDCIPP is a bad actor for a long time, yet it continues to be used,” says Robin Dodson, Sc.D., a research scientist studying indoor air pollution at the Silent Spring Institute in Newton, Mass., who was not involved in the study.

Some scientists and consumer groups think that consumers may be exposed to these chemicals unnecessarily. For example, there has been debate in recent years over whether flame retardants used in furniture are effective enough to outweigh the risks associated with exposure in the first place.

“It’s a very controversial topic,” Stapleton says. “We’re using large volumes of these chemicals in furniture, yet the data suggesting they're effective in preventing fires is minimal to none.”

When reached for comment, the American Chemistry Council, an industry trade association for U.S. chemical companies, said that they had not had a chance to review the study, but they referred us to the Centers for Disease Control and Prevention, which says that detectable levels of a chemical in urine or blood does not necessarily correlate with harm.

The CDC has not responded to a request for comment. 

How to Protect Yourself

Organophosphates and other flame retardants are almost impossible to avoid because so many products contain them and they often are not labeled. Still, there are some things you can do to limit your exposure:

Check the tag on new furniture.
A California law, which went into effect in 2015, requires that all new upholstered furniture sold in the state include a visible label to let you know whether flame retardant chemicals (but not which chemicals) were added.

Consumers outside of California may also be able to find this label on furniture. If you can’t find a tag, ask a salesperson or the manufacturer itself for more information. Curious whether flame retardants are in the furniture you already own? You can send a sample of polyurethane foam to Duke University and researchers will test it free.

Keep dust at bay. In a 2016 study, Dodson and her team, led by researchers from George Washington University, analyzed household dust and found that it contains 45 potentially harmful chemicals, including flame retardants. The compounds can get into your system if you inhale them, touch them, or ingest them.

Children are especially vulnerable because they’re more likely than adults to come into contact with and ingest dust. Wash your hands frequently to prevent getting dust in your mouth when eating or touching your face. Dodson also suggests vacuuming regularly to keep dust levels low. A good air purifier might help, too. (Check our buying guide and ratings of vacuums and air purifiers.)