The Department of Ecology said Tuesday that manufacturers of children's products would be required to report whether their products contain chlorinated Tris, also known as TDCPP.
The Washington Toxics Coalition had asked the state to add the chemical, which has been detected in changing pads, car seats and other children's products. In 2011, the state of California put the chemical on its list of cancer-causing agents.
Last spring, Washington lawmakers considered but did not pass a measure to ban chlorinated Tris and another flame retardant from children's products or upholstered furniture.
Ecology on Tuesday also said it removed a chemical solvent called n-butanol from the list after considering a petition from the American Chemistry Council.