More than 30 years after chemical flame retardants were removed from children’s pajamas because they were suspected of being carcinogens, new research into flame retardants shows that one of the chemicals is prevalent in baby’s products made with polyurethane foam, including nursing pillows, car seats and highchairs.

The research does not determine if children absorbed the chemical, chlorinated Tris, from the products. But in an article to be published Wednesday in the journal Environmental Science & Technology, the researchers suggest that infants who use the products have higher exposure to the chemical than the government recommends.

Earlier research by one of the article’s authors, Arlene Blum, a biophysical chemist, contributed to the elimination of Tris flame retardants, including chlorinated Tris, in children’s pajamas in the 1970s. Although the chemical was not banned at that time, the Consumer Product Safety Commission now says that it “may pose a significant health risk to consumers.”

The new research found that foam samples from more than a third of the 101 baby products that were tested contained chlorinated Tris. Over all, 80 of the products contained chemical flame retardants of some kind, some of which are considered toxic, though legal to use. In one instance, flame retardants represented 12 percent of the weight of the foam in a changing pad; most products were closer to 3 to 5 percent.

Among the products examined were changing table pads, sleep positioners, portable mattresses, baby carriers, rocking chairs and highchairs.

Fourteen of the products contained the flame retardant TCEP, which the State of California describes as a cancer-causing agent. Four of them contained Penta-BDE, a flame retardant that builds up in human tissue and that manufacturers voluntarily phased out in 2004; it is banned in many countries, but not the United States, and in some states, including New York.

“Why do you need fire retardant in a nursing pillow?” said Dr. Blum, who is the executive director of the Green Science Policy Institute, a nonprofit organization that brings scientific data about toxic chemicals to policy makers.

“The whole issue is, they are toxic chemicals that are in our homes at high levels; and right now, people don’t know much about it,” she said.

Asked about the new research, the Juvenile Products Manufacturers Association, an industry trade group, said all nursery products sold in the United States conform to “tough federal safety standards.”

“Not only do these safety standards contain flammability requirements, they also restrict the use of substances that are harmful or toxic and to which children might be exposed,” the association said in a statement.

The association also noted that chlorinated Tris was not banned by the government, but rather a related compound, brominated Tris, also found in the pajamas decades ago. “This study does not support allegations that the banned retardant Tris is in use,” the association said.

Gordon L. Nelson, a chemistry professor at Florida Institute of Technology, said the new research was interesting but hardly proof that the flame retardants were doing harm. He noted that some children’s products that use foams have plastic covers around them, which would prevent flame retardants from leaching out.

“The question is, in actual use, does the flame retardant come out?” Dr. Nelson said. He says he has done research on fire safety for decades and occasionally accepts research money or consulting fees from the industry.

In addition, Dr. Nelson maintained that fire retardants have vastly reduced the number of fire deaths caused by upholstered furniture, a point that critics of the chemicals dispute.

The new research is being released amid a broader, and often bitter, debate about flame retardants and a California flammability rule that has become the de facto national standard.

The California standard, passed in 1975, requires that polyurethane foam in upholstered furniture be able to withstand an open flame for 12 seconds without catching fire. Because there is no other state or federal standard, many manufacturers comply with the California rule, usually by adding flame retardants with the foam, Dr. Blum said.

Last year, California exempted strollers, nursing pillows and baby carriers from the flammability standard. Dr. Blum characterized the exemption as a positive step, though she noted that many other baby products were not exempted and it was not yet clear if manufacturers had stopped using flame retardants in those products.

Dr. Blum is among a group of academics and environmentalists who argue that the California standard exposes people and their pets to toxic chemicals. The flame retardants can migrate from furniture to household dust, and can be ingested by people and pets.

Some of the chemicals used in flame retardants are suspected carcinogens, and studies have linked the chemicals to variety of health issues, including problems with fertility and neurological development, the authors of Wednesday’s journal article said.

Heather M. Stapleton, an assistant professor of environmental chemistry at Duke University and the lead author, complained that current federal oversight of chemicals is so weak that manufacturers are not required to label products with flame retardants nor are they required to list what chemicals are used.

Under current law, it is difficult for the federal Environmental Protection Agency to ban or restrict chemicals. Even now, the agency has yet to ban asbestos, widely known to cause cancer and other lung diseases.

“We can buy things that are BPA free, or phthalate free or lead free. We don’t have the choice to buy things that are flame-retardant free,” Dr. Stapleton said. “The laws protect the chemical industry, not the general public.”

In a statement, the American Chemistry Council, which represents manufacturers of flame retardants, said the products are “well studied and provide important safety benefits.”

“This study attempts to examine the existence of certain flame retardants in a small sampling of children’s products,” the council said, in a statement. “It does not address exposure or risk.”

The Consumer Product Safety Commission has been working on a federal flammability standard for upholstered furniture for 16 years. The current proposal would allow manufacturers to meet the flammability standard without fire retardants. An agency spokesman said that “additional research looking into consumer exposure and the impact of chemical alternatives is needed.”