A new US study has found that child car seats may contain cancer-causing chemicals.

According to CBS News, researchers from Duke University in North Carolina examined the flame-retardant chemicals used in the foam padding in child seats, as well as other baby products.

From a sample of 101 different products, they identified nine with the known carcinogen (cancer-causing agent) ‘TCEP’, five with the neurotoxin (nerve poison) ‘Penta’, which is banned in eight US states, and 36 with ‘chlorinated tris’, which has be labelled a ‘probable carcinogen’ by the US Consumer Product Safety Commission.

Children and adults can be exposed to the chemicals both through the skin by touching the products and through the air by breathing them in, as flame-retardant chemicals are known to escape from foam into the air.

The study did not identify any of the products tested, although CBS revealed chlorinated tris was identified in three car seats made by Evenflo.

An Evenflo representative defended the safety of the brand’s products and said they were no different to any others out on the market.

“Protecting children is Evenflo's number one priority. Evenflo uses the same types of fire retardant materials to meet strict mandatory federal and state flammability requirements as do automobile and other baby and juvenile products manufacturers.”

The North American Flame Retardant Alliance said flame retardants were well studied and highly scientific chemicals that provided vital fire safety benefits.

“The flame retardants currently in use are allowed by the relevant regulatory authorities. Our member companies are on the forefront of innovating new flame retardants, which undergo extensive testing by manufacturers and the safety data are scrutinised by government agencies in the US and abroad.”

US National Institute of Environmental Health Sciences director, Dr Linda Birnbaum, said the research should serve as a “wake-up call” to baby product manufacturers.

“I am concerned about, not only cancer, but reproductive or neurological effects as well. The developing brain,” Dr Birnbaum said.“I think the question should be: ‘why do we need these chemicals in baby products at all?’”