A gas explosion occurred at the ICL/Stockline factory in Maryhill, Glasgow in 2004 resulting in 9 fatalities and many injuries. The cause of the explosion was gas leaking from a buried carbon steel pipe due to external corrosion. This accumulated in an unvented basement of the building until an explosive mixture was present and a source of ignition led to its detonation. The pipe was carrying propane vapour from a storage vessel in the yard into the building and its condition had never been assessed since its installation some 35 years previously.
An inquiry into the explosion was carried out by Lord Gill and the results published as The ICL Inquiry Report.
A major conclusion is that all buried metallic pipework carrying LPG vapour at commercial and industrial premises should be replaced by polyethylene piping. This will be carried out on a prioritised basis following a timetable agreed between HSE and UKLPG with the oldest pipework in the least well-maintained condition and located in the most corrosive soils being replaced first.
This SAFed guidance sets out what to do when inspection work is carried out on LPG installations with buried metallic vapour pipework.
It is available here.
SAFed April 2021