Flame retardants, in particular, polybrominated diphenyl ethers or PBDEs, are of serious concern to children's health. Like other well-known toxic substances like PCBs and dioxins, they are highly toxic and persistent in the environment. Measurements from around the world, including in Canada, show dramatic increases in these substances in the environment, in food, in house dust, and in breast milk. Also like PCBs and dioxins, these chemicals are harmful to children's developing brains.