Firefighters wearing breathing masks spent two hours fixing a potentially fatal nitrogen gas leak inside the Inverness Centre for Health Science.
The gas – toxic if leaked extensively and in an enclosed area – came from a cylinder in a chemical lab occupied by the University of the Highlands and Islands (UHI).
It happened just five weeks after Princess Anne visited students at the Highlands and Islands Enterprise-owned building on Old Perth Road, in her role as UHI chancellor.
Professor Iain Baikie, who has expertise in chemistry and physics and founded Wick-based KP Technology, said: “Any gas leak is bad, a spontaneous one even more so as this might leak for a long time. If nitrogen gas leaks into an enclosed and unventilated space it is dangerous.
“A high pressure gas leak requires immediate attention and it is very serious. There is a potential for serious injury or even fatal injury.
“The fire brigade would have been very careful with their initial situational awareness with a high pressure gas leak.”
Prof Baikie said nitrogen gas is toxic if the leak is extensive and in an enclosed area as the oxygen levels can be depleted enough to cause suffocation.
Nitrogen gas is safe to breathe only when mixed with the appropriate amount of oxygen and is both odourless and invisible. Atmospheric oxygen levels are normally at 21% but a drop to 16% would result in an increased pulse and breathing, while a drop below 10% means death.
Prof Baikie added a big leak could also propel the cylinder into a missile, as the pressure in a cylinder is 200-300 times atmospheric pressure.
Inverness South councillor Duncan Macpherson said he was made aware of the incident by a family member who was attending a dentist appointment at the facility on Saturday.
He added: “It’s alarming that there was a leak of nitrogen. It’s invisible. The fire service were on hand to nullify the threat and make it safe.
“The fire service turn their hands to everything and they were the emergency service who went and dealt with it.”
Two fire appliances from Inverness were called to the building at about 10.20am on Saturday.
A fire service spokeswoman said that firefighters wearing breathing apparatus entered the lab and isolated the gas supply, ventilated the room and used a dry powder extinguisher.
Crews spent about two hours at the scene as it was a chemical incident.
The building was evacuated and no one was hurt, although the incident took place at the weekend when most staff were away.
A UHI spokesman said: “A fire alarm was triggered in a laboratory at the Centre for Health Science on Saturday. The fire service attended and confirmed no fire was detected. We are working to investigate the cause of the issue.”
