Contract packaging applies if the following three criteria are met:

• the packaging is filled with goods at the instruction of a third party (e.g. a supermarket),
• the filled packaging is handed over to that third party, and
• only the name or brand of that third party is visible on the packaging.

As a general rule, the party filling the packaging is considered the producer within the meaning of the Verpackungsgesetz (Packaging Act). The answer as to whether you are under obligation for the respective retail packaging you fill with goods depends on the packaging's specific labelling.