As a rule, gas cylinders with household gas are taken back by the trade. However, this does not apply to older models in particular. In this case, gas cylinders that are no longer used should be disposed of via SDK. Long storage in basement corners and garages increases the potential danger with each passing year. Old cylinders often still contain residues of flammable propane-butane gas. Due to rust and porous seals, they can leak and the gas emitted can cause an explosion.

The preparation of the gas cylinders is carried out in cooperation with various gas suppliers by the Luxembourg company Presta-Cylinders. Cylinders that can still be used can be returned to the cylinder cycle after appropriate treatment.