Eighty percent of cushions used in car seats, portable cribs and other baby furnishings contain chemical flame retardants that can accumulate in babies’ bodies, according to a new study to be published Wednesday.

More than one-third of the tested products contained the same carcinogenic chemical that was removed from children’s pajamas in the late 1970s.

The study, conducted by research chemists from California and North Carolina, suggests that babies are being exposed to at least eight different flame-retarding chemicals in an array of products sold nationwide.

Manufacturers add brominated and chlorinated compounds to polyurethane foam cushions to slow the spread of flames in case they catch fire. The chemicals can leak from the cushions and then babies can inhale or ingest them, or absorb them through their skin.

The study’s lead author, Heather Stapleton, a Duke University assistant professor of environmental chemistry, said many of the compounds have been used in foam cushions only recently, replacing another chemical that was banned after 2004 because it was building up rapidly in human bodies.

“Most people are not aware of the exposure that is occurring,” Stapleton said, adding that the potential health effects of most of the chemicals are unknown.

Research on lab animals has shown some of the chemicals cause cancerous tumors and damage developing brain cells, and some can alter hormones essential to reproductive and neurological development. But for most of the compounds discovered in the baby products, even basic toxicity data is unknown, and the effects on human health remain unstudied.

Linda Birnbaum, director of the federal institute that funded part of the study, said in an interview Tuesday that she is concerned that babies are being exposed to chemicals without adequate information on their health risks.

“Are we moving from one compound for which there is a concern to a newer compound that may be just as bad or worse?" said Birnbaum, director of the National Institute of Environmental Health Sciences. “There are a few [of these compounds] that we certainly have concerns about. There are certainly issues about relatively high concentrations used in these products."

The research team sampled 101 pieces of polyurethane foam removed from cushions in car seats, changing table pads, sleep positioners, portable crib mattresses, nursing pillows, baby carriers, high chairs and a few other products.

Eighty of them contained at least one flame retardant.

“In general, the flame retardant chemicals detected were not associated with a particular type of product, manufacturer, or the year of purchase,” the researchers wrote in the peer-reviewed study published Wednesday in the journal Environmental Science and Technology.

The chemicals are added to furniture cushions to meet a California flammability standard adopted in 1975, which requires them to withstand a 12-second open flame. Although it is not a national standard, much of the nation’s furniture contains flame retardants to comply with it.

The chemicals were found to be so widespread in the products that it’s difficult for parents to avoid them. One item contained three different flame retardants, and some products had levels of the chemicals that made up as much as 12.5 percent of the foam’s weight, according to the study.

However, some manufacturers use a filling other than polyurethane foam, such as polyester, which can pass the flammability standard without the chemicals. Products that are advertised as free of flame retardants include BabyLuxe organic pads and mattresses, OrbitBaby strollers and car seats and Boppy nursing pillows. Those items were not tested for the study.

 Birnbaum said the most common chemical found in the baby products -- known as chlorinated Tris -- mutates DNA and may be carcinogenic. Some are organophosphates, similar to pesticides that have been banned and are known to harm developing brains.

"I would like to know whether these chemicals are developmentallly neurotoxic and I would like to know whether they are carcinogenic," Birnbaum said.

NIEHS is now doing basic testing on at least 40 flame retardants, Birnbaum said. Those tests will answer basic questions about changes in cells and genes; they are not the elaborate, years-long studies exposing lab animals or examining humans that can answer most important health questions.

Some of the ingredients are considered trade secrets, and there is little public information on the volumes used or the results of basic safety tests submitted to the Environmental Protection Agency.

"Some of these compounds aren’t new. Some of them have been around for a long time and no one really knows how much they have been used," Birnbaum said.

Study co-author Arlene Blum, executive director of the Green Science Policy Institute in Berkeley, Calif., said “it’s hard to believe” that the same chemical that was used in pajamas in the 1970s is now back in use in other baby products.

In 1977, Blum co-authored a paper in Science magazine recommending a ban on the Tris chemicals in sleepwear because they entered children’s bodies, could mutate DNA and might cause cancer. The Consumer Product Safety Commission banned the brominated version in sleepwear that year. For the chlorinated version, the commission asked retailers to label sleepwear that contained it, and it was phased out in the garments.

Now, the new tests confirm that it's back in other baby items. Sixty of the 101 car seats, changing pads and other products contain chlorinated Tris, the most common chemical found. Industry is using it to replace a furniture flame retardant, called penta, which was banned after 2004 because it was building up in human bodies and breast milk.

"I don’t think anyone dreamed that when they replaced penta, they would put in chlorinated Tris," Birnbaum said.

In addition to causing cancerous tumors in rats, researchers suspect that the Tris and other chlorinated flame retardants might disrupt hormones and damage developing brains and reproductive systems. Duke researchers reported last year that it altered development of rat brain cells. The effects on the brains of infants and fetuses, however, have not yet been studied. Also, in one study, adult men with higher levels had reduced thyroid hormones.

Another 17 of the 101 products contained a fairly new brominated compound called Firemaster 550. Firemaster 550 was developed by Chemtura Corp. as a replacement for penta. The potential health effects of Firemaster 550 are unknown, although Stapleton said there “are some concerns” that it could have reproductive effects. It also damaged DNA in fish experiments.

The penta compounds – banned since 2004 -- were found in five of the 101 products – four purchased before 2004 and one from a second-hand store. Researchers in New York City last year reported lower IQ scores in toddlers and preschoolers and reduced motor skills in 12-month olds with higher prenatal concentrations of the penta compounds.

A representive of the American Chemistry Council, which represents chemical companies, did not respond Tuesday to a request for information on the flame retardants.

The next step for scientists will be to measure the chemicals in infants. Stapleton's group recently developed a method to test for a breakdown product of Tris in urine.

The scientists suspect that American babies may be exposed to higher levels of many of the flame retardants than adults or older children.

A 2006 Consumer Product Safety Commission report found that U.S. children’s exposure to Tris in furniture is five times higher than the amount the agency considers acceptable. The study authors said infants’ levels are likely to be much higher than other children’s because they have smaller body weights and spend a lot of time around the products.

“Exposure to chemical additives in baby products is of even greater concern for infants, who are in intimate contact with these products for long periods of time, at very critical stages of development,” the researchers wrote.

Stapleton, who gave birth to a baby girl two weeks ago, said she tries to avoid all baby products made of polyurethane foam that have a label indicating they comply with California’s flammability standard.

”But sometimes it's hard to find products... For example, we didn't find any car seats not treated with flame retardants,” she said. “I did remove the polyurethane foam pad from my changing table and I purchased an organic polyester/cotton-based pad instead.” 

This article originally ran at Environmental Health News, a news source published by Environmental Health Sciences, a nonprofit media company.