A new study released Wednesday claims 60% of children's car seats tested by the Ecology Center this year contained at least one toxic chemical. The study was posted by the consumer site HealthyStuff.org.

More than 150 2011-model car seats sold in Michigan were tested for bromine, chlorine, lead, other heavy metals, and allergens. This substances are linked to allergies, birth defects, impaired learning, liver toxicity, and cancer.

Most Toxic 2011 Car Seats:

Infant Seat: Graco Snugride 35 in Edgemont Red/Black & Graco SnugRide 30 in Asprey

Convertible Seat: Britax Marathon 70 in Jet Set & Britax Marathon in Platinum

Booster Seat: Recaro Pro Booster in Blue Opal & Recaro ProSPORT Toddler in Misty

Least Toxic 2011 Car Seats:

Infant Seat: Chicco KeyFit 30 in Limonata, Graco Snugride 35 in Laguna Bay & Combi Shuttle 33 in Cranberry Noche

Convertible Carseat: Graco Comfort Sport in Caleo, Graco MyRide 65 in Chandler and Streamer, Safety 1st OnSide Air in Clearwater, and Graco Nautilus Elite 3-in-1 in Gabe

Booster Seat: Graco Turbo Booster in Anders

The car seats were tested with a portable X-Ray Fluorescene device.

For the complete list of car seat rankings click here.