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.