Hospitals should sell e-cigarettes and remove smoking shelters from their grounds, health officials have said.
However, Public Health England said e-cigarettes could be contributing to at least 20,000 successful new quits per year and advised local stop smoking services recommend the use of e-cigarettes to those trying to quit.
Academic Ann McNeill, professor of tobacco addiction at King's College London said: "When people smoke tobacco cigarettes, they inhale a lethal mix of 7,000 smoke constituents, 70 of which are known to cause cancer".
Wrongly, thousands of smokers think vaping is just as unsafe as cigarettes.
The HSE has said the ban on vaping devices and electronic cigarettes in Irish hospitals will continue - despite fresh calls for them to be officially licensed as medical aids for quitting smoking.
But Professor Martin McKee, of the London School of Hygiene and Tropical Medicine, pointed out that a more extensive review in the USA, published two weeks ago, was much more "cautious" about e-cigarettes' long-term safety.
It has called for e-cigarettes to be made available for sale in hospital shops.
Prof. Linda Bauld, Professor of Health Policy at the University of Stirling and Chair in Behavioural Research for Cancer Prevention at Cancer Research UK, said: "Concern has been expressed that e-cigarette use will lead young people into smoking".
'We hope this reports will...encourage the 40 percent of smokers who've failed to quit but never tried vaping to go ahead and switch, ' it said in a statement.
There are two parts to being a smoke-free hospital, one is not allowing smoking on the premises, the other is helping every smoker to quit.
"Our new review reinforces the finding that vaping is a fraction of the risk of smoking, at least 95 per cent less harmful, and of negligible risk to bystanders".
"It would be tragic if thousands of smokers who could quit with the help of an e-cigarette are being put of due to false fears about their safety".
"Anything that the [Medicines and Healthcare products Regulatory Agency] MHRA can do to make it easier for manufacturers we think would be helpful", said PHE health improvement director John Newton.