A new study out this week finds more than half of children's cars seats sold in the U.S. are hazardous to your child's health. What a scary thought -- something designed to protect your child may actually be harmful.

The Ecology Center, based in Michigan, found 60 percent of the 150 car seats tested contained chemicals that can permanently affect a child's developing brain. The study lists the chemicals as bromine and chlorine.

Studies in lab animals have found that bromine-containing flame retardants can permanently affect the developing brain, while PVC has been classified by the US Environmental Protection Administration as a known human carcinogen.

The center has posted its findings at healthystuff.org, including a list of the best and worst car seats.