All passengers on-board a train towards the East were forced to alight and board the next train at Tanjong Pagar MRT station on Thursday morning (7 Jun).
The incident was due to white smoke fuming out from beneath the train when it pulled into the station at around 9:45am.
Preliminary investigtion by the transport company, found freon gas coming out off a faulty air-conditioning compressor. Because of an oil leak the compressor had become overheated, and it released Freon gas into the train and platform area.
Freon gas is a common refrigerant used in air-conditioners and is non-toxic, but it interacts with moisture in the air to form an odourless white smoke. Prolonged exposure to Freon gas, especially when it is deeply inhaled, can cut off oxygen to the lungs.
Margaret Teo, SMRT’s vice-president of corporate communications explained that for safety precaution, all passengers on board the affected train were asked to alight and board the next train.
The incident didn’t help the train delay occurring at that point of time along the East West Line (EWL) on Thursday morning. It is also uncertain if the delay was caused by this incident as there was no official announcement by SMRT about the delay.
Responding to Non-Constituency Member of Parliament Mr Leon Perera's questions on how many incidences of freon gas leaks on the MRT and LRT rail systems have occurred over the past 10 years; and what is the risk posed to commuters by such gas leaks, Mr Khaw Boon Wan said there have been 23 instances of freon gas leaks on trains over the past 10 years.
Mr Khaw noted that freon gas can interact with moisture in the air to form an odourless white smoke and that the smoke poses no health risk to the public.
"As soon as a leak is reported, affected commuters are de-trained at the next station, and the train withdrawn for repair." said Mr Khaw.