(www.MaritimeCyprus.com)Â On September 29, 2022, a horrific maritime disaster unfolded in the waters off the coast of Vietnam. The Chinese-registered bulk carrier, MV "WUZHOU 8", was transiting from Koh Sichang, Thailand, to Lianyungang, China, laden with over 50,000 tonnes of cassava chips. Within hours, a toxic emergency struck the vessel, incapacitating all 21 crew members. Despite international rescue efforts, the incident resulted in 13 fatalities, leaving only 8 survivors.
A comprehensive safety investigation report released by the Maritime Safety Administration (MSA) of China reveals how a routine cargo fumigation turned into a lethal, invisible trap.
The Incident Timeline: A Rapidly Unfolding Emergency
The tragedy began with cargo operations in Thailand and culminated in a frantic night at sea:
September 27, 2022: A local Thai fumigation company applied aluminium phosphide tablets to the top of the loaded cassava chips across all holds. The holds were closed, and the vessel departed.
September 28, 2022: Crew members sealed the hatch cover joints with asphalt tape. Over the course of the day, several crew members reported smelling a pungent, garlic-like or chemical odour on deck.
September 29, 2022 (2200 hours): While sailing 52 nautical miles south-southwest of Con Son Island, Vietnam, the Third Officer and an Able Seaman on the bridge suddenly experienced acute symptoms—nausea, severe vomiting, chest tightness, and fatigue.
September 30, 2022 (0100–0400 hours): The illness rapidly spread through the ship. The Master, believing the crew had caught a cold or suffered food poisoning, ordered traditional remedies like ginger water. By 0400 hours, 17 crew members were severely incapacitated, forcing the Chief Officer to stop the engines and signal that the vessel was "not under control".
September 30, 2022 (Afternoon): The Vietnam Maritime Search and Rescue Centre (VMSRC) dispatched rescue helicopters to evacuate the crew. The Master passed away on board before evacuation, and 12 other crew members subsequently succumbed to the poisoning.
Uncovering the Cause: Food Contamination vs. Gas Inhalation
Initially, the crew and company suspected severe food poisoning or a COVID-19 outbreak. However, comprehensive forensic testing by the Ho Chi Minh City Public Health Research Institute entirely ruled out contaminated provisions, water, or shipboard medications.
Instead, the autopsy findings for 12 of the deceased crew members pointed uniformly to toxic pulmonary oedema, a classic manifestation of acute phosphine gas poisoning.
How the Gas Penetrated the Living Quarters
The investigation identified a fatal combination of mechanical deficiencies and atmospheric conditions that allowed the gas to trap the crew:
Positive Pressure in the Holds: The aluminium phosphide tablets absorbed moisture from the high-humidity cargo holds, rapidly decomposing into phosphine gas. Because the cassava chips filled the holds nearly to the top, the gas accumulated in a tight space, creating high positive pressure.
Defective Seals: On-site flooding tests later revealed aged rubber seals and gaps in the cargo hold access covers, alongside accommodation doors that could not fully close. The pressurized gas escaped the holds and lingered on the deck.
The "Downwind" Trap: On the evening of September 29, the vessel altered its course, matching its speed closely with the southwesterly winds. This created a stagnant micro-climate where the escaped phosphine gas accumulated directly in front of the accommodation block instead of dissipating.
Negative Pressure in the Living Spaces: The ship's air conditioning system was running in recirculation mode, which generated negative pressure inside the lower accommodation deck. This pressure differential acted like a vacuum, drawing the highly toxic phosphine gas through the gaps of the faulty doors directly into the crew's living spaces and the bridge.
Critical Safety Issues Identified
The China MSA report highlighted severe systemic failures both on board the vessel and within the shipping company's management framework:
1. Absence of Detection Equipment: The MV "WUZHOU 8" was completely stripped of any phosphine gas detection equipment. The crew had no way to monitor gas concentrations or confirm their suspicions when they smelled the initial chemical odours.
2. Inadequate Crew Knowledge: The crew lacked basic awareness regarding the profound hazards of underway fumigation. They failed to cross-reference their rapidly progressing symptoms with the Safety Data Sheets (SDS) of the fumigants being used.
3. Deficiency in Shore-Based Support: While the company's vessels frequently carried cargoes requiring fumigation, its Safety Management System (SMS) contained zero guidance or risk assessments for underway fumigation operations.
4. Formalistic Procedures: The ship's officers signed off on the fumigation paperwork as a compliance exercise without executing safety briefings, crew education, or posting mandatory hazard warning signs.
Key Safety Recommendations for the Fleet
To prevent a recurrence of such a catastrophic event, the safety report outlines mandatory protocols for all shipping companies managing underway fumigations:
Update Safety Management Systems: Shipping companies must embed rigorous "Ship Cargo Hold Fumigation Operation Instructions" into their SMS, strictly aligned with IMO circulars ($MSC.1/Circ. 1264$).
Mandatory Gas Monitoring: Every vessel performing underway fumigation must be equipped with specialized gas detection instruments, testing components, and comprehensive crew training to monitor gas concentrations throughout the voyage.
Enhanced Personal Protective Equipment (PPE): At least four complete sets of respiratory protective equipment must be accessible, alongside the latest Medical First Aid Guide for Use in Accidents Involving Dangerous Goods (MFAG) and appropriate antidotes.
A Rule of Caution: If any crew member experiences physical discomfort during or immediately following a fumigation operation, the possibility of toxic gas poisoning must never be ruled out or misdiagnosed as food poisoning or standard illness.
For more details, click below to download the full China MSA investigation report:
Source: China MSA
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