Two workers died in 2024 after being exposed to hydrogen sulphide gas
The Ministry of Manpower (MOM) has taken enforcement action against a contractor and one of its managers for alleged safety breaches linked to a workplace incident at PUB's Choa Chu Kang Waterworks that left two workers dead.
Charges were filed against Stargroup Est Pte Ltd, the contractor engaged to carry out tank cleaning operations at the facility, and Lim Beng Hock, Stargroup's authorised manager for confined space entry permits.
Stargroup was charged with one count under the Workplace Safety and Health (Risk Management) Regulations for "failing to implement reasonably practicable measures to minimise the risk to any person who may be affected by its undertaking at the workplace," according to MOM.
Lim faces 12 counts under the Workplace Safety and Health (Confined Spaces) Regulations for "failing to exercise all due diligence when performing his function as authorised manager in relation to the issuance of confined space entry permits."
Toxic gas incident
The charges come after a fatal incident in May 2024 that left two workers dead.
In the incident, a team of four workers from Stargroup and its subcontractor were carrying out cleaning works inside a water treatment process tank.
Three of the workers collapsed after entering an enclosed passage beneath the tank to close hand valves that had been opened to drain water.
Two workers died at Ng Teng Fong General Hospital, while the third was discharged after receiving medical treatment.
MOM's investigations found the workers had been exposed to hydrogen sulphide gas, which the ministry described as "a toxic gas that is typically emitted when sludge is drained from water treatment tanks."
"Hydrogen sulphide gas is colourless and can be lethal even at low concentrations," MOM said.
"At the time of the incident, sensors installed at the location recorded hydrogen sulphide levels that exceeded safe thresholds and the alarm had been triggered."
Further enforcement actions
Meanwhile, MOM also issued a stern warning to a PUB officer for failing to cooperate with his employer to comply with the Workplace Safety and Health Act (WSHA) the night before the incident.
PUB was separately offered composition for allowing its employees to enter the confined spaces for short periods without adequate ventilation on previous occasions.
Following the incident, MOM had issued a stop-work order to PUB, which was lifted on 6 August 2024.
MOM reminded employers that they are legally required to conduct risk assessments before confined space works commence, test the atmosphere within the confined space, provide appropriate respiratory protective equipment, and ensure a trained standby person is stationed outside the confined space at all times.
"The WSHA requires stakeholders to take reasonably practicable measures to ensure the safety and health of persons who may be affected by work activities," it said.
"The publication issued by the WSH Council in September focusing on confined space-related incidents serves as a guide for industry stakeholders and aims to reinforce awareness of good practices for protecting workers from confined space hazards."
