New research has shown that dangerous flame retardants can be found in preschool and childcare settings, potentially exposing children to toxic compounds.

In response to growing health concerns, in 2006 California banned the use of two types of polybrominated diphenyl ethers (PBDEs) - a compound used as a flame retardant.

But furniture products made before the ban still contain the products, which can cause neurodevelopmental delays in children.

In a study published in the journal Chemosphere, researchers at the University of California (UC), Berkley tested for the presence of 14 PBDEs and four non-PBDE flame retardants in 40 California child care centers. The facilities were located in a mix of urban, rural and agricultural areas, and served 1,764 children.

Researchers discovered both PBDE and non-PBDE flame retardant compounds in 100 percent of the dust samples tested.

"These findings underscore how widespread these materials are in indoor environments," lead author Asa Bradman said in a UC Berkley statement. "Children are more vulnerable to the health effects of environmental contaminants, so we should be particularly careful to reduce their exposure to harmful chemicals."

The types of furniture found in these day care centers may be to blame: 29 facilities had upholstered furniture and 17 had foam napping equipment for children. Facilities utilizing foam equipment had significantly higher levels of PBDEs compared to those without foam products.

Many infants and young children spend up to 50 hours per week in day care, researchers stress.

The state's current flammability standard requires that foam in consumer items such as nap mats and bassinets can withstand a small open flame for 12 seconds without igniting. Researchers are now asking these guidelines to be updated to eliminate the need for flame retardants in furniture.

"Consumers should verify that the furniture they are buying is free of flame retardants, especially when children will be exposed," Arlene Blum, who has done past research on flame retardants, noted.