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 at Petrochemical Corporation of Singapore, and Dr Peter Nagler, chief innovation officer at the Agency for Science, Technology and Research, the Ministry of Manpower (MOM) said in a statement yesterday.

"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 yesterday 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 five are out of critical condition and have been moved into high dependency wards, said Mr Zaqy.

The ministry also set out five tasks for the committee yesterday.

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 yesterday. "It's... extremely alarming for many of us (and we are) deeply concerned (about) how we started this year."

There were 11 fatal workplace accidents last month.

Mr Zaqy 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.

He said the injured workers will be interviewed as part of the investigations, after they have had some time to recover, and 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."

Asked if small and medium-sized enterprises (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 (the) WSH Council (Workplace Safety and Health Council), and many training providers and industry associations do provide safety training. It is a requirement to have trained safety officers on board."

In the Feb 24 incident, a fire broke out at fire protection systems firm Stars Engrg at the Tuas site, leading to an explosion. Ten people, including the three who later died, were taken to hospital. Two have been discharged.

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