SINGAPORE — A freon gas leak from a train’s faulty air-conditioning pipe caused Tanjong Pagar MRT station to be engulfed in an odourless smoke on Monday (Aug 15) afternoon, and hordes of commuters were seen dashing out of the train in an online video clip. 

Rail operator SMRT said that the incident happened around 2.50pm, and staff members “switched on the tunnel ventilation system immediately to disperse the odourless gas”. 

Ms Margaret Teo, head of corporate marketing and communications at SMRT, said that the gas leaked into the tunnel and reduced visibility at parts of the station when the platform doors were opened for passengers to leave the train. No injuries or fire were reported. The affected train was towed to Ulu Pandan Depot for inspection, and the train operator, police and the Singapore Civil Defence Force are investigating the matter. 

Freon, a colourless and odourless gas, is toxic in large quantities, and areas are normally evacuated and closed off when the gas is released. In November 2008, a freon gas leak on a Russian nuclear submarine due to its faulty fire extinguishing system killed 20 people.

When TODAY arrived at the scene at about 3.30pm, the smoke had dissipated and train services were operating normally. 

Mr Jason Wang, 38, who works in sales and boarded the affected train at Raffles Place MRT station, said that smoke billowed from the gap between the platform and the train once it pulled up at Tanjong Pagar: “There was not much of a smell, but my first thought was, ‘What if there’s a terrorist attack?’ When the other commuters saw the smoke, they all quickly started running out.”

He said officers at the MRT station made an announcement for commuters not to take any videos and photographs. Commuters evacuated themselves out of the train, according to Mr Wang, who works in sales and was travelling from the Raffles Place MRT station to Tanjong Pagar.

He added that a subsequent announcement declared that the platform was closed due to a train fault.

Mr Jeremy Tan, 25, another commuter who witnessed the incident, said thick smoke emerged around 3pm as he was in a train headed towards the Clementi MRT station. “When you see thick smoke you will definitely panic a bit,” he told TODAY, while stressing that passengers did not flee in a chaotic manner. SMRT staff were also “quite efficient” in ushering passengers from to safety.

The passengers did not have to leave the station, according to Mr Tan, a student with the Singapore Institute of Management. The next train arrived about five to seven minutes later, and they were allowed to continue with their journey.

There was some smoke in the new train, added Mr Tan, though his journey to Clementi was otherwise smooth.