The filling of refillable CO2 cylinders must only be carried out under certain conditions: it must be a secured room and a TÜV tested CO2 gas filling station. The latter checks the weight of the empty cylinder and only fills the prescribed quantity since overfilling may result in hazards. The shipment of filled CO2 cylinders is possible, but there are some regions in Europe where the dispatch by post or flight may be problematic (e.g. to islands). The TÜV date is visibly stamped on the cylinder. Cylinders, where the TÜV is expired, may not be filled. TÜV inspections can be carried out in various institutions, but not at JBL.