An Ann Arbor-based environmental group says some child car safety seats are much better than others when it comes to exposing children to potentially dangerous chemicals.

Car seats save lives. Its absolutely essential that parents put their children in them while driving, said Jeff Gearhart, the Ecology Centers clean car campaign director. However, some car seats are safer than others when it comes to chemical composition. makes it easy for parents to choose the least toxic car seat for their child.

The center tested 62 models of safety and booster seats for chemicals including bromine, chlorine, lead and heavy metal allergens,substances which have been linked to major health problems such as liver, thyroid and developmental problems in children,according to the center

Children have the highest exposure and are the most vulnerable population in terms of exposure to chemical-laden dust and inhaling toxic fumes, since their systems are still developing.

The Ecology Center is the same group that recently released the consumer guide to toxic chemicals in cars and they used the same research methodology to test child car seats.

The new study found that the best seats had no brominated flame retardants, no PVC and low levels of other chemicals tested.

While more than 40 percent of seat cushions tested contained no brominated flame retardants and 77 percent of the seats were free of PVC-plastic, more than 33 percent of all seats tested had one or more components which contained higher levels of toxic chemicals.

A complete ranking of all of the car seats that were tested can be found on the web site.

While there are numerous substances in car seats that can lead to health and environmental problems, the Ecology Center selected those for testing with known toxicity, persistence, and tendency to build up in people and the environment.