SCOPE AND FIELD OF APPLICATION This publication provides information on how to safely vapor-free and clean mobile tanks used in the transportation of flammable or combustible liquids. The term mobile tank used in this publication refers to tank trucks (wagons) and tank cars (rail cars) or any mode of conveyance which is operated on land@ roads or railroads. It does not apply to marine transportation nor to mobile tanks used for compressed or liquified gases. Attention Is called to the measures which should be taken to: a) Protect personnel against harmful vapor concentrations or oxygen deficiency. b) Avoid the ignition of flammable vapors which may be present during certain phases of cleaning and/or repair operations.