Northern Ireland ushered in a new cultural era today as smoking was completely stubbed out in the workplace - including pubs, cafes and restaurants.
History was made at the stroke of 6am when it became illegal to light up in almost all enclosed public and workplaces across the province.
Experts estimate the new laws will save around 250 lives across Northern Ireland every single year - through protecting people from second-hand smoke and prompting smokers to kick the habit.
Today's eagerly-awaited development has overwhelming public support, despite fears of the impact it may have on pub trade.
The legislation sees Northern Ireland fall into line with Scotland, Wales and the Republic. England will follow in two months' time.
Health Minister Paul Goggins was among the first to welcome the new legislation, which is considered the biggest public health initiative of our time and marks a new cultural chapter for us all.
"Second-hand smoke is a toxic cocktail of around 4,000 chemicals - many of which cause cancer. It is internationally accepted that there can be no safe level of exposure to second-hand smoke," he said.
"Non-smokers exposed to second-hand smoke are 20-30% more likely to develop lung cancer - not to mention the other illnesses and diseases. It is regrettable and astonishing that second-hand smoke accounts for the loss of around 278 lives each year in Northern Ireland.
"People do not want to breathe in other people's smoke. That was made very clear at the consultation stage of this legislation. By reducing our level of exposure, this legislation will improve health and save lives."
Evidence from Scotland and the Republic has shown that there has been a massive improvement in air quality in bars and restaurants as a result of smoke-free legislation. The Republic, which went smoke-free three years ago, has already seen an 83% reduction in air pollution in pubs and an 80% decrease in airborne carcinogens for both patrons and staff.
Dr Brian Gaffney, chair of the Smoke-free Northern Ireland coalition and chief executive of the Health Promotion Agency for Northern Ireland, said today is one for celebration.
"Smoking is the single greatest preventable cause of premature death and avoidable illness in Northern Ireland. It claims around 3,000 lives every year - most of which are preventable - and one person dies every two weeks due to exposure to second-hand smoke.
"Everyone has the right to clean air and from today, as people across Northern Ireland make their way into work, they will know that they are guaranteed protection from the deadly effects of second-hand smoke."
Chief executive of the Northern Ireland Chest, Heart and Stroke Association, Andrew Dougal, said: "Time and again we hear evidence of how people living with lung disease are affected by the tobacco fumes of others.
"Many dreaded their appointments at Belfast City Hospital because of people smoking cigarettes at the entrance. They were also effectively excluded from pubs and hotels.
"One sufferer recently told me that she could no longer go to bingo because of the pall of smoke in the hall. For all of these people, this day has been a long time coming."
However, not everyone is happy. Simon Clark, director of the smokers' lobby group Forest (Freedom Organisation for the Right to Enjoy Smoking Tobacco), said the ban makes Northern Ireland "a less liberal, more intolerant place".