Tuas fatal blast: Company, man convicted over safety lapses in 2021 tragedy that killed 3 workers

SINGAPORE - A company involved in the installation of fire protection systems and one man linked to it were convicted over safety lapses that caused a blast that killed three employees in 2021.

The victims – Bangladeshis Shohel Md, 23, and Anisuzzaman Md, 29, and Indian national Subbaiyan Marimuthu, 38 – were killed when a mixer machine at Stars Engrg’s worksite in Tuas Avenue 11 exploded on Feb 24 that year.

They died from severe burns that covered 90 per cent of their bodies. Seven other workers – five from Stars and two from another nearby firm – were injured.

Following a 21-day trial, Stars and Singaporean Chua Xing Da, 42, were each convicted on May 26 of two charges under the Workplace Safety and Health Act (WSHA) over safety lapses.

Chua was the sole director of Stars and oversaw the worksite’s operations.

He and the company failed to ensure the mixer machine was safe to use.

They also failed to ensure their employees had received adequate training and supervision to operate the equipment.

In giving his verdict, District Judge Tan Jen Tse said more could have been done to ensure the safe use of the machine.

He also said Chua and Stars failed to take measures to ensure that it was used properly.

Myanmar national Lwin Moe Tun, 36, who was a project engineer at Stars, was acquitted of a charge under the WSHA.

He had been accused of negligently doing an act that endangered employees’ safety by allowing them to repair the mixer machine’s damaged heater.

The judge said there was not enough evidence that Lwin Moe Tun allowed repairs to the machine.

Deleted messages

But Judge Tan convicted him of two obstruction of justice charges after he deleted messages between himself and Mr Subbaiyan after the incident.

Court documents stated that Lwin Moe Tun had removed them from mobile phones belonging to himself and Mr Subbaiyan.

Chua was convicted of instigating him to delete the messages.

In earlier proceedings, the court heard that Chua and Lwin Moe Tun oversaw the production of fire-retardant wraps at the worksite.

These wraps comprised an aluminium sheet exterior and were made of various layers, including a clay-like lining that Stars called “fire clay”.

Deputy public prosecutors Timotheus Koh, Grace Chua and Mohamed Riasudeen stated in court documents that fire clay was manufactured at the worksite using a mixer machine that Stars purchased in August 2019.

It was installed at the worksite in June 2020.

The mixer machine had an oil jacket meant to contain “heat transfer fluid” and transfer heat from built-in heaters to the contents of the machine’s mixing chamber.

The machine came with two resistance temperature detectors (RTDs).

The prosecutors said that under Chua’s direction, the mixer machine was operated with insufficient oil, causing overheating and over-pressure within its oil jacket.

The RTDs were also not used properly, with no proper temperature control or monitoring within the oil jacket.

This resulted in the jacket rupturing, leading to the release of pressurised oil out of it and forming a liquid aerosol that was ignited, resulting in the explosion.

An inquiry into the blast found that the initial rupture of the oil jacket resulted in the explosion, and subsequent flash fires were most likely caused by the combustion of potato starch powders that accumulated at the work site.

Red flags

The prosecution argued that Chua knew the mixer machine was not safe to use, especially after several “red flag” incidents.

In August 2020, a spark and smoke were seen around the machine’s heaters, and the oil jacket leaked later that year.

In February 2021, a fire occurred near a drain valve at the bottom of the oil jacket.

The DPPs told the court: “Instead of investigating and addressing the root cause of ‘red flag’ incidents, Chua chose to adopt a... poorly informed approach in response to (them), which resulted in the unsafe operation of the mixer machine.”

During the trial, Chua said he did not think the incidents such as the fire and the leakage were red flags.

As to the obstruction of justice charges after the explosion, the prosecutors said Chua knew that Lwin Moe Tun had Mr Subbaiyan’s phone.

And there were messages between Lwin Moe Tun and Mr Subbaiyan about the unsafe changing of a faulty heater on the device.

Court documents stated these communications would be relevant to the investigations.

Yet, Chua told Lwin Moe Tun it was “ok” to delete these messages from the Myanmar national’s phone.

The prosecution argued that Lwin Moe Tun admitted he had deleted messages from his phone and from Mr Subbaiyan’s as he did not want to be involved in the investigations.

Lawyer Foo Cheow Ming represents Lwin Moe Tun, while Mr Chia Boon Teck represents Chua and Stars.

The mitigation and sentencing for the three offenders will be held on June 25.