If you were on a train at Tanjong Pagar on Monday at 3pm, or near Tanjong Pagar MRT station for that matter, you might have seen this:

Passengers were seen running out of a train engulfed in white smoke that spilled onto the station platform. According to a report on Channel NewsAsia, some commuters said SMRT staff were on the scene instructing passengers not to film or take photos of the incident.

TransCom Police were reportedly also on scene to guide passengers away from the platform and up to the gantry area.

Huge plumes of smoke out from the train that pulled into Tanjong pagar mrt station! pic.twitter.com/MCncDJVSkD

— ZOE RAYMOND (@zoeraymond) August 15, 2016

Not sure what just happen here at Tanjong Pagar MRT!! pic.twitter.com/APiKRGVcx2

 

Not sure what just happen here at Tanjong Pagar MRT!! pic.twitter.com/APiKRGVcx2

— اسوادي روس (@IswadiRos) August 15, 2016

 

As early as 4pm, people were already asking the train operator for more information about the incident:

Almost two hours after it happened, SMRT released the statement below at 4.45pm:

At 2:53pm this afternoon, passengers at Tanjong Pagar MRT station were detrained from a westbound train due to a leak of freon gas from the train’s air-conditioning system. The discharge of freon into the tunnel reduced visibility at parts of the station when the platform screen doors were opened for passengers to exit the train. SMRT staff switched on the tunnel ventilation system immediately to disperse the odourless gas. The train was withdrawn from passenger service to allow the air-conditioning system to be checked. The passenger platform at Tanjong Pagar MRT station remained in service during this incident and train services were not affected.

We apologise to passengers affected and will be investigating the cause of this incident.

Now the next question on everyone's mind is —

What is Freon gas?

We did a tiny bit of research:

Freon is a brand name for a group of colourless, odourless, nonflammable, noncorrosive chlorofluorocarbons (CFC). If you paid attention in science class, this is the stuff that kills the ozone layer.

Freon cools when it evaporates, making it a wonderful refrigerant, and so it's used extensively as a cooling agent, most often in air-conditioners.

Fortunately for us, Freon gas is not harmful at low doses and does not cause long-term harm. According to this, it might cause dizziness and suffocation at very high concentrations, so chances are the passengers on the train and in the station when the leak happened were not exposed to too much of it.

It's funny the topic of Freon gas is coming up now, though, since SMRT did an air-conditioner failure analysis between December 2015 and February this year.

In the blog post talking about it, the company said when there is a Freon gas leak from the air-conditioning units, "cooling efficiency" is reduced.

They also said they are stepping up efforts to plug these leaks, in a process called "brazing"... guess they need to step up on these stepped-up efforts, given what happened on Monday afternoon.

Oh well. On the bright side, it's not as bad as experiencing 3 breakdowns in a day.

Top image: screenshot from Twitter user @zoeraymond.

If you like what you read, follow us on Facebook and Twitter to get the latest updates.