A dispersion safety factor for LNG vapor clouds

► We proposed a new parameter: the dispersion safety factor (DSF). ► DSF is the ratio between the distance reached by the LFL and that reached by the visible cloud. ► The results for the DSF agree well with the evidence from large scale experiments. ► Two expressions have been proposed to calculate DSF as a function of HR. ► The DSF may help in indicating the danger of ignition of a LNG vapor cloud.