Tanker crew member who modified breathing mask linked to colleague’s death gets over 3 months’ jail

SINGAPORE – A crew member of a Vietnam-registered chemical tanker

modified two self-contained breathing apparatus (SCBA) masks

before his colleague wore one to enter a tank on board for cleaning.

The colleague, Mr Hoang Van Chau, 40, fell unconscious in the tank – previously used to transport naphtha gas – and died from exposure to volatile hydrocarbons.

Naphtha is commonly used as a solvent and sometimes as fuel for camp stoves. Exposure to naphtha can cause headaches, dizziness, nausea and vomiting.

On July 2, Le Thanh Dung, 36, who was a pump master on board GT Win at the time of the offence, was sentenced to three months and two weeks’ jail after pleading guilty to one count of performing a rash act that endangered lives.

The incident also allegedly involved Nguyen Duc Nghi, 49, who was then the captain, and Dao Tien Manh, 31, the chief officer at the time. Their cases are pending.

All three men and the victim are Vietnamese.

Deputy Public Prosecutor Joseph Gwee told the court that GT Win had sailed from Thailand to Singapore with multiple tanks of naphtha gas as cargo.

It arrived here shortly before 11pm on May 11, 2024, and was berthed at Sudong Anchorage.

At around 5pm the next day, the unloading of cargo from the vessel was completed at Advario Singapore’s terminal on Jurong Island.

After that, the vessel anchored at the Raffles Reserved Anchorage. 

At around 2pm on May 14, 2024, Manh told the victim and three other crew members to clean some tanks that were not declared gas-free.

DPP Gwee said: “(Manh’s) role was to check for the oxygen level in the tanks before cleaning and perform the requisite safety checks before the tanks were cleaned by the crew.

“If the tank was not declared gas-free, the crew members should not have entered the tank.”

Court documents stated that Manh instructed Dung to make modifications, which involved attaching a mask’s connector to a hose linked to the valve of an air bottle on the deck.

The hose was secured with a clamp to prevent air leakage.

The DPP said the modification was made as it was “impractical” for the men to don the heavy SCBA while entering the tank owing to space constraints at a staircase.

It was not stated in court documents how an unmodified SCBA mask is supposed to function, or what the standard operating procedures were.

Between 2pm and 4pm that day, Dung modified two masks despite knowing they were unsafe for Mr Chau and the other three crew members to use when performing their task.

While in the tank, Mr Chau fell unconscious and was rescued.

Dung then showed Nghi the modified mask that Mr Chau had worn.

DPP Gwee said Nghi threw the mask into the sea and told the crew members to lie to the police so that Mr Chau could get an insurance payout.

The crew members performed cardiopulmonary resuscitation on the victim, and Nghi contacted his company to request emergency medical assistance.

Mr Chau was eventually taken to Marina South Pier, where he was pronounced dead at around 10.40pm. 

During an investigation, Dung initially maintained in two written statements that Mr Chau was found unconscious inside tank 6.

He subsequently admitted that the victim was found in tank 4, which was not declared gas-free at the time.

Dung, Nghi and Manh were charged in court in 2025.