Xiu said they also bought two steering wheels in Germany, one for a Chevrolet Aveo, but found no PAHs in any of them.

"We hope the quality watchdog could pay attention to the issue and set standards to limit PAHs in auto products," he said.

Zhao Ping, vice-president of the Cancer Foundation of China, said PAHs are common in our daily lives.

"PAHs may not directly relate to cancer but the chemical could probably increase the risk of contracting cancer," he said.

Ge Youshan, a lawyer specializing in consumer rights with the Beijing Lawyers Association, said auto manufacturers should have a sense of responsibility to ensure customers' legal rights rather than merely pursuing profits through lowering costs.

Car producers should compensate customers if their products cause injury or illness, he said.

"Automakers should regulate their parts production and supply, and adopt the same standards in every market," said Ge.

The General Administration of Quality Supervision, Inspection and Quarantine did not respond to questions from China Daily by Tuesday.