Ireland became the first country in Europe on Monday to impose an outright ban on smoking in workplaces.
Smoking bans are becoming more common
BBC News Online examines whether smoking bans are justified.
Controversy has surrounded the introduction of laws prohibiting public smoking in places like California and New South Wales and there is still debate over whether they work.
Supporters say they prevent passive smoking, encourage smokers to quit and prevent people taking up the habit, while opponents argue they damage business and are ineffective.
But once it is clear how the ban has worked in Ireland it is thought there may be a "domino effect" across Europe.
The Irish legislation makes it an offence to smoke in workplaces, which has the effect of banning smoking in pubs and restaurants.
A Dutch law bans smoking in public places including railway stations, trains, toilets and offices. But hotels, bars and restaurants there have won a temporary reprieve until 2005.
UK-based pro-smoking group Forest describes it as a "ludicrous law" and spokesman Simon Clark admits he is nervous about the ban spreading across the Irish Sea.
But Dr Fenton Howell, a public health specialist and spokesman for Action on Smoking and Health Ireland, said the move was primarily a health and safety issue, freeing people from having to work in a smoky environment.
He said the evidence in favour of a ban was "incontrovertible", because of studies showing the dangers of passive smoking.
"We have a duty to protect people in law, if nothing else to give them a safe workplace," said Dr Howell.
The UK has so far steered clear of such laws despite the appeals of the British Medical Association (BMA), which advocates a ban.
Dr Peter Maguire, deputy chairman of the BMA's science committee, works in Northern Ireland just four miles from the Republic and says he will be eating out south of the border from now on.
"As an Irishman, who in the name of God would have thought the Irish would be the first in Europe to ban smoking in public places?" he said. "It's a national hobby in Ireland."
In fact, latest figures show the proportion of Irish people who smoke regularly is now just 25%, down from 31% in 1998.
Dr Maguire is confident the ban will have the desired effect of both stopping people smoking in the first place and, arguably more difficult, getting current smokers to quit.
He said: "If you're out in the pub you will know you can't smoke and you may be less inclined to when you have to go out into the cold every half-hour or so away from your company."
The potential benefit to a country of a ban can be gauged in billions of pounds, according to supporters, given the cost of treating smoking-related diseases like cancer and heart disease. There are thought to be 7,000 tobacco-related deaths each year in Ireland.
The other camp worries however about the effect on pub and restaurant takings if smokers are forced to stay away.
But the reaction where bans have been introduced has been largely favourable. A study carried out two years after public smoking was outlawed in California found that 73% of people were in favour of it.
The proportion of people smoking, however, had remained at a steady 18%, though the average age at which people quit dropped from 48 to 43.
Another study in New South Wales found restaurants had little to fear, with 76% reporting normal trade, 14% increased trade and just 9% reduced trade after the ban came into effect there.
The most startling figures of all came from a small study in Helena, Montana, in the US after a ban apparently halved the number of heart attacks.
Smoking was only prohibited for six months before a legal challenge curtailed the legislation, but during that time the average number of heart attacks a month fell from the usual seven to just three.
But even the doctors who led that research warned a far bigger study in a large city was required to prove the true effects of such a ban.
There is also the question of civil liberties. Forest said encouraging pubs, hotels and restaurants to introduce smoke-free areas according to customers' wishes was a fairer approach than bringing in legislation.
But Dr Howell said: "There have been no major problems where bans have been brought in because in most places, most people don't smoke and most smokers actually want to quit."