- MOM has charged contractor Stargroup Est Pte Ltd and its authorised manager over alleged workplace safety lapses linked to the fatal confined space incident in May 2024.
- Two workers died and a third was injured after being exposed to hydrogen sulphide gas.
- MOM issued a stern warning to a PUB officer and a composition fine to PUB over separate workplace safety breaches uncovered during its investigations.
A cleaning contractor and its authorised manager has been charged over alleged workplace safety lapses that led to the deaths of two workers while injuring another at a Tuas sewage treatment plant.
The Ministry of Manpower (MOM) has taken enforcement action against the Stargroup Est Pte Ltd (Stargroup) contractor for failing to implement reasonably practicable risk control measures to minimise risks to persons at the workplace.
Lim Beng Hock, the company’s authorised manager for confined space entry permits, faces 12 charges for allegedly failing to exercise due diligence.
Meanwhile, MOM also issued a stern warning to a PUB officer for failing to cooperate with his employer in complying with workplace safety requirements on the night before the incident.
The ministry also issued PUB a composition fine for allowing employees to enter confined spaces for short periods without adequate ventilation on previous occasions.
About the incident
The incident occurred on 23 May 2024 during tank cleaning operations at Choa Chu Kang Waterworks.
At the time, PUB was the occupier of the facility, while contractor Stargroup had taken over a water treatment process tank to carry out cleaning works.
A team of four workers from Stargroup and its subcontractor had been deployed for the operation. During the works, three workers entered an enclosed passage beneath the tank to close hand valves that had earlier been opened to drain water from the tank.
They subsequently collapsed inside the confined space.
The three workers were taken to Ng Teng Fong General Hospital, where two later died on 24 and 28 May 2024. The third worker was discharged after receiving medical treatment.
MOM’s investigations found that the workers had been exposed to hydrogen sulphide gas, a colourless and highly toxic gas commonly released when sludge is drained from water treatment tanks.
MOM said the gas can be fatal even at low concentrations. Sensors installed at the site had recorded hydrogen sulphide levels exceeding safe thresholds, triggering an alarm at the time of the incident.
Following the incident, MOM issued a stop-work order requiring PUB to cease cleaning works on pre-treatment water tanks and prohibit entry into adjacent confined spaces.
The order was lifted on 6 August 2024 after PUB had met the ministry’s stipulated safety requirements.
Upholding workplace safety
MOM reminded employers that the Workplace Safety and Health Act (WSHA) requires all stakeholders to take reasonably practicable measures to protect the safety and health of persons who may be affected by work activities.
For works involving confined spaces, employers are legally required to:
- conduct risk assessments before work begins;
- test the atmosphere within the confined space;
- provide workers with appropriate respiratory protective equipment;
- ensure a trained standby person is stationed outside the confined space throughout the operation.
Meanwhile, workers are responsible for complying with all confined space safety requirements, including wearing the required protective equipment and following established safe work procedures.
To help industry strengthen workplace safety practices, the Workplace Safety and Health Council has published a guidance document in September 2024 on lessons learnt from confined space-related incidents.