Many students were unaware of the need for carbon monoxide alarms

The study also found that almost a quarter of students thought a smoke detector would detect carbon monoxide, which kills up to 50 people a year.

Scottish Gas has urged students to report rogue landlords who fail to provide gas safety certificates.

The company has launched a campaign using beer mats shaped like tombstones to promote the safety message.

Scottish Gas said the beer mats would be placed in university bars. They carry the epitaph of a fictional character who died from carbon monoxide (CO) poisoning.

These landlords are breaking the law - it's as simple as that Chris Bielby Scottish Gas

A message on the back urges students to "nag their landlord" about gas safety records.

The gas safety certificate is required by law and guarantees that appliances are safe.

Scottish Gas and the National Union of Students (NUS) want landlords who flout the law to be struck off university accommodation lists.

The research also showed that despite almost a quarter of students feeling their health and safety was at risk in their rented homes, more than 40% chose their homes because they were cheap, with only one in 10 putting safety first.

The students questioned admitted that if they had �30 to spare they would spend it on clothes, music and alcohol rather than on ensuring their flat was safe.

Less than one in four students had a carbon monoxide detector in their home compared to 93% who had a smoke detector.

'Hugely important'

One in eight incorrectly believed it was adequate that appliances were safety checked every five years.

Chris Bielby, head of safety at Scottish Gas, said: "These landlords are breaking the law - it's as simple as that.

"A gas safety record isn't like a washing machine or a fridge. It's not something that's good to have. It's something all students are entitled to by law."

James Alexander, depute president of NUS Scotland, said: "It is hugely important that students take safety issues seriously.

Warning signs

"Students are entitled to a good quality, safe living environment for their money and rogue landlords should be a thing of the past."

CO warning signs for gas appliances are:

• Stains, soot or discolouring around a gas fire, water heater or boiler
• An appliance that burns with a yellow or orange flame instead of a blue one
• A strange smell when the appliance is on
• Increased condensation inside windows.

If these signs are present then stop using the appliance, open doors and windows to ventilate the room and do not use the appliance again until it has been checked by a Corgi registered engineer.

Symptoms of CO poisoning include recurring headaches, nausea, sickness, chest or stomach pains, general tiredness and fatigue.