Contractor, manager charged over fatal 2024 Choa Chu Kang Waterworks toxic gas incident

MOM said its investigations found that the workers had been exposed to hydrogen sulphide gas, 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.

“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,” said the manpower ministry.

Stargroup was charged on Thursday for failing to implement reasonably practicable measures to minimise the risk to any person who may be affected by its undertaking at the workplace.

The authorised manager for confined space entry permits of Stargroup, Lim Beng Hock, was also charged for failing to exercise all due diligence in relation to the issuance of the permits. 

OTHER ENFORCEMENT ACTIONS

MOM said it also issued a stern warning to a PUB officer for failing to cooperate with his employer to enable his employer to comply with the Workplace Safety and Health Act on the night before the incident.

It has also fined PUB for allowing its employees to enter the confined spaces for short periods without adequate ventilation on previous occasions.

“Employers carrying out work in confined spaces are reminded that they are legally required to conduct a risk assessment before works commence, test the atmosphere within the confined space, provide workers with appropriate respiratory protective equipment, and ensure that a trained standby person is stationed outside the confined space at all times,” said MOM.

Workers also have the responsibility to comply with all confined space safety requirements, including using the required protective equipment and following safe work procedures, it added.  

After the incident, MOM issued a stop-work order to PUB to cease cleaning works on pre-treatment water tanks and entry into confined spaces adjacent to these tanks.

The stop-work order was lifted on Aug 6, 2024 after PUB satisfied the stipulated conditions.