SINGAPORE - A senior district judge has been appointed to lead the inquiry into the fatal Tuas explosion that killed three workers.

Senior district judge Ong Hian Sun will chair the inquiry committee and be assisted by Mr Lucas Ng, general manager of plant, Petrochemical Corporation of Singapore, and Dr Peter Nagler, chief innovation officer at A*Star, the Ministry of Manpower (MOM) said in a statement on Friday (March 5).

"The inquiry committee will look into and ascertain the causes and circumstances that led to the explosion and make recommendations to prevent the recurrence of such accidents," the ministry said.

The dates and venue of the inquiry will be announced at a later date. Its proceedings will be held in open court.

The committee visited the Tuas incident site with Senior Minister of State for Manpower Zaqy Mohamad on Friday and were briefed on the status of the investigations, MOM said.

Three workers died and another five are still in hospital following the fatal blast.

The three who died were: Mr Marimuthu S, 38; Mr Shohel Md., 23; and Mr Anisuzzaman "Ani" Md., 29.

Their bodies were repatriated to their home towns in India and Bangladesh on Thursday.

All five remaining workers are out of critical condition and have been moved into high dependency wards, said Mr Zaqy on Friday.

The ministry also set out the five tasks for the committee on Friday.

First, to inquire into and ascertain the causes and circumstances of the accident that led to an explosion.

Second, to make recommendations to prevent the recurrence of such an accident at workplaces.

Third, to consider the evidence put before the committee by the Attorney-General's Chambers.

Fourth, to submit a report of its proceedings, findings and recommendations to MOM.

Finally, if the district judge who chairs the inquiry committee is of the opinion that criminal proceedings ought to be instituted against any person in connection with the accident, he shall also forward a copy of the report to the Public Prosecutor.

"This shows our commitment over the long haul because this was just one of the (incidents) that we had in February," said Mr Zaqy on Friday. "It's... very extremely alarming for many of us (and we are) deeply concerned (about) how we started this year."

He added that the inquiry committee is working with forensic experts, the police and the Singapore Civil Defence Force, and that the findings should be ready in three to six months.

Mr Zaqy said the injured workers will be interviewed as part of the investigations, after they have had some time to recover, adding that the interviews will be an important component of the investigation.

He added that the inquiry committee will be independent and that MOM will consider its recommendations and proposals.

"We'll see what to do next, whether it is (a) change in regulations policy, or even enforcement and prosecution if need be," he said.

Asked if SMEs lacking resources to conduct risk assessments was a concern, Mr Zaqy said: "I don't think the response of being an SME is an excuse. "There are relevant resources. We've got WSH Council (Workplace Safety and Health Council) and many training providers and industry associations do provide safety training and it is a requirement to have trained safety officers on board."

A fire broke out at fire protection systems firm Stars Engrg on Feb 24, which then led to an explosion. Ten people were taken to hospital, and two have since been discharged.

Preliminary investigations found that the explosion was caused by the accumulation of potato starch in a confined environment.

After a visit to the accident site last Thursday, MOM's Workplace Safety and Health commissioner Silas Sng said: "It is a known scientific fact that materials in powder form can be explosive when they are dispersed in the air in an enclosed environment.

"Potato starch is one of the materials that this particular company used for its product. Over time, the dust can accumulate, especially if the ventilation or housekeeping is inadequate."

An MOM spokesman on Sunday said the last time a combustible dust explosion occurred here was in 2013. Two workers sustained minor injuries and the occupier was fined $5,000.

MOM later conducted an enforcement operation targeting chemical companies processing powders, and issued a circular to guide companies on managing risks of combustible dusts.

According to its website, Stars Engrg was incorporated in 2010.

The last time an inquiry was convened for a workplace accident was in 2004 to investigate the Nicoll Highway collapse that killed four people.

On Wednesday, Mr Zaqy said in Parliament that inspections on close to 500 companies that may have combustible dust hazards have started.

To ensure better workplace safety and health, MOM will also be releasing a framework later this year that emphasises safety performance for public sector construction tenders.

This means that safer companies will have better access to business opportunities, said Mr Zaqy during the debate on MOM's budget in Parliament.

5 tasks of the inquiry committee

• The committee has to inquire into and ascertain the causes and circumstances of the accident that led to an explosion;

• Make recommendations to prevent the recurrence of such an accident at workplaces;

• Consider the evidence put before the committee by the Attorney-General's Chambers; and

• Submit a report of its proceedings, findings and recommendations to MOM.

• If the district judge who chairs the inquiry committee is of the opinion that criminal proceedings ought to be instituted against any person in connection with the accident, he shall also forward a copy of the report to the Public Prosecutor.