BBC News Northern Ireland 31 October 2012 Last updated at 06:35
Carbon monoxide alarms in new NI homes now compulsory
Carbon monoxide alarms have become a legal requirement in all new homes in Northern Ireland.
The new law comes as research suggests half of the UK population mistakenly believe their household smoke alarms will alert them to the gas.
The law follows the deaths of two teenagers from carbon monoxide poisoning in August 2010.
Neil McFerran and Aaron Davidson died after a gas leak in a holiday apartment in Castlerock, County Londonderry.
The two young men, who were 18 years old, had been staying at the apartment near Coleraine with a third friend, Matthew Gaw, who survived. The three friends were found by relatives.
Their families have welcomed the news but said it only reaches about 5% of properties. They have called for more to be done.
"I think it's a great forward step, but this is only going to be new buildings, they still could go further," Aaron Davidson's mother Catriona said.
"We still need to push awareness of carbon monoxide, that it is a killer."
The new law also requires that an alarm be fitted whenever a boiler or solid fuel stove is upgraded or replaced.
A survey carried out by the Carbon Monoxide - Be Alarmed! campaign states that only 39% of people have a carbon monoxide alarm.
It also suggests that half of the UK population mistakenly believed their smoke alarm would alert them to carbon monoxide gas.
The research was carried out in September among 3,458 UK adults. It said 81% of those surveyed know that carbon monoxide can kill.
Carbon Monoxide - Be Alarmed! is the national campaign to reduce the number of deaths and injuries caused by carbon monoxide.
The campaign is run by Energy UK on behalf of Britain's six major gas and electricity companies, in partnership with the Dominic Rodgers Trust.
From 31 October, Northern Ireland Building Regulations will require a carbon monoxide detector or alarm "in the room where the appliance is located. However, if the combustion appliance is installed in a room or space not normally used e.g. a boiler room/cupboard, the detector/alarm should be located just outside the room or space".
The research findings also included:
57% of respondents said they did not have an audible carbon monoxide alarm in their home - the equivalent of more than 35 million people in Britain. A further 4% said they did not know if they had one. 93% of those surveyed agreed that a similar law to that being introduced in Northern Ireland should be considered for the rest of the UK. Many people did not know carbon monoxide can also cause long-term health problems, including heart problems (93% unaware), long-term brain damage (62% unaware) and respiratory problems (34% unaware).
Carbon monoxide is produced when fuels such as gas, oil, charcoal, coal and wood do not burn completely.
The most common cause of this is when an appliance, such as a boiler or cooker, is installed incorrectly or poorly maintained. Carbon monoxide can also build up when flues, chimneys or vents are blocked.
The Department of Health estimates that 50 people are killed by carbon monoxide poisoning, and at least 4,000 are treated in hospital, in the UK each year.
However, the Carbon Monoxide - Be Alarmed! group says that figure is likely to be much higher, as carbon monoxide poisoning is very difficult to diagnose because symptoms are often similar to common illnesses like flu and food poisoning.
Meanwhile, safety checks carried out by the fire service in more than 22,000 homes across Merseyside in England found that fewer than one in 10 had a carbon monoxide alarm.
Yes - we do have a CO alarm.