Abstract: There is provided a process for reversibly solidifying hydrocarbons for transportation or storage to prevent spillage of the hydrocarbon. The process involves mixing the hydrocarbons with a sufficient quantity of a hydrocarbon wax, such as paraffin, heated to the liquid state, and cooling the resulting mixture until it solidifies into a firm, united mass. The minimum amount of hydrocarbon wax required to solidify the oil will depend on the type of crude oil, the type of wax being used and the temperature that the solidified mass is being maintained at during shipping. In the case of crude oil shipment by ocean tanker the crude may be pre-treated with the hydrocarbon wax in the storage compartments and the mixture transported in solid form. The solidified, united mixture effectively prevents spillage of the crude in the event of the hull being ruptured and is not displaced by sea water. The buoyant solidified mixture prevents the ship from sinking in the event of a hole being formed in the hull of the ship.