BSafe Case Study 24 — Six Days Sealed, and No Gas Detector Would Have Caught It

Sealed for Six Days, Then Reopened

The ship arrived in Chennai to load 53,000 tonnes of yellow corn. Fumigation contractors came aboard to install ducting. Loading was intermittently halted by rain; cargo hold four was fully loaded and sealed on day one of a roughly two-week loading operation, with loading continuing in other holds as weather allowed.

Six days later, as loading neared completion, 21 fumigation contractors boarded to prepare hold four for fumigation. Two workers entered the hold's booby hatch wearing gas masks and carrying a phosphine gas detector — the equipment matched to the hazard they expected: fumigant gas, not the atmosphere the hold actually had.

A Rescue Attempt With No Protection At All

Within minutes, one worker came back up feeling breathless and reported the other had collapsed inside. He went back in to help. Other contractors, realising something was wrong, tried to assist but retreated, themselves struggling to breathe. Someone alerted the crew at the gangway. The officer of the watch informed the master, who called an enclosed-space rescue over the PA system.

The chief officer reached the booby hatch, saw both men down, put on an emergency escape breathing device, and entered — retrieving one worker, then going back in with a rope for the second. Both received first aid and oxygen before being taken to hospital by car. One was declared dead; the other recovered. Toxicology found no gaseous poison in either man's blood or lungs. The atmosphere hadn't poisoned them — it had simply run out of oxygen.

Why the Detector Didn't Save Them

• The hold had been sealed for six days with a hygroscopic cargo (corn) inside — respiration and microbial activity in stored grain steadily consumes oxygen in a closed space, a well-documented hazard independent of any fumigant.
• The contractors carried a phosphine gas detector, matched to the fumigation job they were there to do — not an oxygen meter, which is what would have actually caught this specific hazard.
• The instinct to go back in and help a collapsed colleague is exactly what put a second, then a third person at risk — without any breathing apparatus, in a confirmed collapse scenario.
• The chief officer's own rescue, while ultimately successful, used an EEBD — escape-only equipment — to enter, the same equipment-mismatch pattern seen in other enclosed-space cases.