99040 Arsine Incident

Arsine Incident
Report No. 99040

I run courses on Dangerous Goods and regularly quote the Arsine incident which was mentioned in the MARS report in May this year. About two years ago, by strange coincidence, an officer who had been on the ship at the time of the incident attended one of the courses. I was therefore able to confirm with him the details as I understood them. I believe that the story bears repeating as it is an extreme example of what can happen if the transport of dangerous goods rules are not followed.

The ship was sailing across the North Atlantic towards Europe. On nearing the south west coast of England, four seamen were sent to check the lashings and they were all overcome by the fumes in one of the holds. Their condition was very severe and they were taken ashore by helicopter. This happened in 1974, eighteen years later I heard that two of these men were still very ill and a couple of years after that they died.

The incident arose because two cylinders of Arsine gas, properly marked and labelled, were placed inside a freight container without any markings or placards on the outside. I am not sure whether they had been initially secured inside the container but, if there had been any lashings, they broke and the two cylinders were rolling around inside the container. The result was that the valves became damaged and the gas was released. Furthermore, the Arsine gas had not been declared to the ship. The result of the non-declaration was that the container had been stowed in the hold instead of on deck (Arsine Gas is Stowage Category D). The gas has the significant property of being considerably heavier than air. Accordingly, the released gas sank rather than rose in the hold atmosphere. If the container had been correctly stowed on deck, the released gas should have escaped into the air.

It is of great concern that there is still evidence of non-compliance with the IMDG Code. The fact that some of the crew on this vessel died as a result of the Code not being followed should be a lesson to all.