The World Health Organisation (WHO) has issued its strongest warning to date about e-cigarettes, claiming they increase the risk of heart disease and lung disorders.

In a new Q&A and a series of strongly worded Tweets released on Tuesday afternoon, the organisation said vaping was particularly risky for the developing brains of teenagers, and could damage a growing foetus.

They also warned e-cigarettes expose non-smokers and vapers to nicotine and other harmful chemicals and said there was little evidence that they helped smokers to quit.

The WHO said governments should consider taxing the products in a similar way as cigarettes and regulating their promotion and use.

“E-cigarettes are harmful to health and are not safe,” said the organisation.

“E-cigarettes increase the risk of heart disease and lung disorders. They pose significant risks as they can damage the growing foetus. They also expose non-smokers to nicotine and other harmful chemicals.

“They are particularly risky when used by adolescents. Nicotine is highly addictive & young people’s brains develop up to their mid-twenties. Exposure to nicotine can have long-lasting, damaging effects.”