Tragedy struck at Choa Chu Kang Waterworks on Thursday, May 23, when a PUB sub-contractor died after inhaling hydrogen sulphide gas while carrying out tank cleaning works. Two other workers, who also inhaled the gas, are currently in intensive care. All three workers are foreigners, with the deceased being a 40-year-old Indian national and the two injured workers being Malaysians aged 39 and 24.
The incident occurred at around 11:15 am when the three workers were found collapsed while carrying out routine tank cleaning works. Preliminary investigations suggest that they had inhaled hydrogen sulphide, a gas produced from sludge, a by-product of the water treatment process. The gas is highly toxic and flammable, with a potent, unpleasant odor similar to that of rotten eggs or sewage.
The Singapore Civil Defence Force (SCDF) was alerted to the Hazardous Material (HazMat) incident and responded promptly. Firefighters and HazMat specialists, wearing breathing gear, entered the area and identified the hydrogen sulphide. Two water jets were used to disperse the vapour, which took an hour to clear.
PUB has expressed its deepest condolences to the deceased’s family and is cooperating fully with the investigation. The national water agency has called a safety timeout for similar operations in confined spaces and is reviewing the associated safety measures. This safety timeout will apply to all its facilities and will be lifted once the necessary safety measures are in place.
The Ministry of Manpower (MOM) is investigating the incident and has instructed PUB to stop all tank cleaning works. MOM has emphasized the importance of proper ventilation to prevent the accumulation of toxic vapours and the need for workers to be protected from excessive exposure to toxic vapours by equipping them with gas monitoring devices and personal protective equipment such as respirator masks and breathing apparatus.
This tragic incident serves as a stark reminder of the importance of prioritizing safety and health in the workplace. It is crucial for employers and contractors to ensure that their workers are provided with a safe working environment and the necessary protective equipment to prevent such incidents from occurring.