Abstract: A modular packaging system of containers each having a generally tubular, hollow container body of a fiber-reinforced composite material with cooperative mating interlocking elements extending axially along its length. The interlocking elements allow the containers to be stacked and palletized in a stable manner. An interface between a closure mechanism and the container body provides a good seal and prevents fraying or brooming of the fiber-reinforced composite material at the end face of the body.