New_ HSE Research Report 1113- review of Vapour Cloud Explosion (VCE) Incidents

This report was jointly commissioned by the US Pipeline and Hazardous Materials Safety Administ ration (PHMSA) and the UK Health and Safety Executive (HSE). It based on the review of 24 major VCE incidents focussing on source terms, cloud development and explosion mechanics. The incidents studied are from around the globe, including the UK’s  Buncefield Oil depot explosion in 2005. and are split between permanent fuel gases C2-C4 (e.g. LPG) and volatile liquids C4 -C6 (e.g. gasoline).

One of the key findings of the study was the high proportion of vapour cloud incidents which have occurred in nil/low wind conditions. In such conditions the vapour cloud will often continue to grow undetected and large vapour clouds will almost always ignite.

On the inside cover of the report it states that “These findings have important implications for safety practitioners considering installations where such releases of flammable substances can occur. They reinforce the importance of the main risk control measures of overfill prevention and maintaining plant integrity; but they also suggest that the value of mitigation measures such as vapour detectors and vapour barriers should be reviewed.” To read the complete report please go to