You can rely on POLYex: POLYex from WERIT is the first choice for transporting flammable liquids and in potentially-explosive atmospheres for Ex zones 1 and 2. For added safety there is an internal container with multiple plastic layers from which the outer layer is permanently discharging.
The filling material is earthed by the conductive valve and the earthing cable connected to the frame. The ribbing on the cover also prevents any hazardous static load.