Container Explosion: Self-Heating Chemical Cargo Leads to Incident
On August 7, YM Mobility departed from Shanghai and headed to Ningbo. On August 9, a crew member on duty detected an “irritating odor” while on the bow of the ship. Around 13:31, he inspected the involved container and observed a hissing sound, white smoke, and yellow liquid dripping from the door, which are indicative of TPBP decomposition. Over the next six minutes, the smoke intensified. The crew members on the bow recognized the danger and evacuated the area, while the captain activated the fire alarm to gather the crew.
By 13:38, white smoke had obscured most of the starboard bow, and within minutes, it spread across the foredeck. At 13:46:30, the reefer container exploded violently, propelling six containers overboard and disintegrating three others. Fortunately, no injuries were reported, and all crew members safely evacuated to the dock shortly after.
Source: CMSA
First responders from the shore took over firefighting efforts, and by the next morning, the fire was under control. It took an additional day to completely extinguish the last hot spots in nearby containers.
A post-accident inspection revealed that the force and heat from the explosion were sufficient to warp the hatch coaming, hatch cover, and adjacent structures. More than a dozen containers were either burned, exploded, or had their contents damaged.
CMSA pointed out that reefer containers are airtight and thermally insulated, meaning that any heat from a self-heating substance like TBPB would accumulate inside the container, especially in hot weather. Under these conditions, the cargo could continue to heat up until it reached thermal runaway and exploded.
CMSA concluded that “no attention was paid to the temperature changes in the box during transportation,” labeling the arrangement as negligent. They stated, “The transportation plan of transporting TBPB in unplugged refrigerated containers during the hot season is inappropriate… TBPB shippers failed to consider the thermal insulation and airtightness of unplugged reefers in hot weather.“
