Washington, Aug 27 (IANS): Substances used in e-cigarettes such as liquid nicotine can be fatal if ingested, yet most parents who use e-cigarettes are not aware of the dangers, finds a new study done at the Washington University school of medicine in St. Louis.

Instead of tobacco, e-cigarettes vaporise a liquid mixture of nicotine, glycerine and glycol ethers. The liquid form is flavoured, which appeals to children.

But if ingested, a teaspoon of this "e-liquid" can be lethal to a child, and smaller amounts can cause nausea and vomiting that require emergency care. Exposure to skin also can sicken children, doctors warned.

"These are largely avoidable risks, but because e-cigarettes are relatively new, many people - including paediatricians - aren't aware of the dangers or the steps that should be taken to protect children from them," said first author professor Jane Garbutt.

For the study, 658 parents and guardians completed surveys about their knowledge and use of e-cigarettes.

The researchers found that 36 percent of the e-cigarette users neither locked up e-liquid bottles nor used childproof caps.

E-liquid most commonly was stored in a drawer or cupboard (34 percent), a purse or bag (22 percent) or on an open counter (13 percent), the study showed.

"Three percent of the people in our study said a child of theirs had tried to drink the e-liquid," Garbutt said.

Last year, a toddler in New York died after ingesting liquid nicotine intended for use in an e-cigarette.

The researchers were surprised that e-cigarettes were used in so many homes, yet few parents were aware of these risks.

"Ingestion is bad, of course, but even skin exposure to e-liquid can harm children," Garbutt said.

The study was published in the journal Academic Paediatrics.