NEA fined $230k for safety lapses in 2021 Tuas incineration plant explosion that claimed two lives

SINGAPORE – The National Environment Agency (NEA) has been fined $230,000 for safety lapses in the 2021

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The incident on Sept 23, 2021 claimed the lives of two NEA employees – Mr Kwok Yeow Wai and Mr Wee Eng Leng. A third employee – engineer Low Yin Choon – sustained serious injuries.

NEA and two of its employees were charged with workplace safety offences in December 2023 following an investigation that involved several agencies, including the Ministry of Manpower (MOM) and the Singapore Civil Defence Force.

Christopher Lee Yew Binn, divisional director of the waste infrastructure operations and management division of NEA at the time, and Ng Wah Yong, then general manager of TIP, were

under the Workplace Safety and Health Act.

Lee’s case has been fixed for a pre-trial conference on Nov 28. Ng’s case will be mentioned again in court on Nov 20.

On Nov 18, NEA pleaded guilty to one charge of failing to take necessary measures to ensure the safety and health of its employees at work.

The lapses included a failure to ensure that the permit-to-work (PTW) system implemented for high-voltage switchgear racking works was in compliance with electrical installation regulations.

The PTW is a formal authorisation system used in an organisation to control selected work activities to ensure safe execution of work onsite.

Deputy Public Prosecutor Agnes Chan said the PTW allows for hazards to be assessed by suitably qualified persons.

Investigations also revealed that the engineering manager on the day was not authorised to issue a PTW to Mr Kwok.

The prosecutor added that the authorised person was not informed that high-voltage electrical works would be taking place on the day of the incident.

She said the PTW system was “defective” and lacked the essential gate-keeping function when dealing with high-risk work.

NEA also failed to adequately implement control measures and establish safe work procedures for high-voltage switchgear racking works.

The court heard that prior to the accident, NEA had provided its teams with personal protective equipment (PPE) gear for maintenance works that did not include fire-retardant properties.

This was despite a risk assessment, which was conducted prior to the accident, showed that there was a risk of explosion and burns.

DPP Chan said Mr Kwok and Mr Wee had suffered extensive burns in the incident.

Mr Kwok was pronounced dead at the scene, while Mr Wee succumbed to his injuries at the hospital, she added.

The prosecutor said that Mr Low sustained burns over 27 per cent of his body, including his face, neck and limbs. He was hospitalised from Sept 23, 2021 to Oct 18 the same year, and given 223 days of hospitalisation leave.

In 2024, Ms Grace Fu, Minister for Sustainability and the Environment, provided details of the incident in a ministerial statement.

Mr Kwok, Mr Wee and Mr Low had obtained permission from the plant’s control room to troubleshoot an electrical fault when an induced draft fan could not be switched off from the central control room, where the equipment is normally controlled.

Ms Fu said the fan is used to extract gases from the incineration process for discharge via the chimney. It is about two metres wide.

While troubleshooting, the three men entered an electrical switch room.

“At the electrical switch room, a localised explosion happened near the switchgear. Mr Kwok died at the scene, and Mr Wee was seriously injured.

“Mr Wee succumbed to his injuries three days later. Mr Low was also injured in the explosion, but has recovered and returned to work,” said the minister.

Following the incident, MOM issued a Stop Work Order. The Stop Work Order was eventually lifted by MOM on Nov 24, 2021.

The court heard that the team could not remotely shut down the plant because a worn-piston from the machine had dislodged and dropped into a position where it blocked the circuit breaker from tripping.

Mr Kwok, Mr Wee and Mr Low were sent to troubleshoot the fault after a PTW was issued.

The explosion occurred when they conducted a live-racking procedure despite the plant being live.

Senior Counsel Jason Chan, who is representing NEA, said the incident was “unprecedented and unexpected”.

He said that both the prosecution and defence had agreed that the plant’s safety mechanism had been compromised by the dislodged piston, which blocked the safety interlock mechanism.

Mr Chan said NEA deeply regrets the incident, but added that the explosion was not caused through the lapses the agency is pleading guilty to.

He emphasised that the PTW issued to Mr Kwok, Mr Low and Mr Wee on Sep 21, 2023, was to troubleshoot the plant, not to perform any racking works.

“The safety interlock mechanism could not activate on the day of the accident because of the dislodged piston. These are the facts which led to the arc flash explosion,” he added.

“NEA accepts that in the aftermath of the incident, there were things it should have done earlier and it has taken responsibility for those.

“But the key point is those lapses did not contribute to the actual death and injuries that occurred,” said Mr Chan.

In response, DPP Chan said it was clear that the electrical maintenance branch (EMB) team had carried out prohibited live racking, which later led to the arc flash explosion.

But that does not deflect from NEA’s failures, which led to the accident.

“We submit that relevant question for the court is why the EMB team was allowed to carry out the live racking in the switch room in the first place,” she said.

District Judge Luke Tan found that NEA’s failings had caused grievous harm, which resulted in the death of two men and devastating injuries to the third victim.

He rejected arguments by defence, which had attributed the arc flash explosion to prohibited live racking works and the jammed piston.

In throwing out the argument that the explosion was not NEA’s fault, the judge said that the conditions that led to the incident were contributed by multiple areas of failure on the part of NEA.

Judge Tan said there were systemic failures by NEA. He noted the PTW that was issued had provided a broad picture of the issue and simply stated that there was an electrical fault that needed rectification.

The court earlier heard that NEA had also failed to provide suitable fire-retardant personal protection equipment to its employees, despite earlier identifying that the nature of work with high-voltage switch racking could expose workers to possible risk of burns and injuries

NEA stopped operations at the Tuas incineration plant in February 2022, after 36 years of service, as planned. The plant was eventually decommissioned in July 2022.

During its 36 years of operations, there were no other serious or fatal work injuries at the plant.