A method of testing a sterilization process for a packaging member such as, for example, for containers or machines, may include the steps of acting upon at least one first region of the packaging member or of the machine with an oxidizable medium. The method further includes acting upon at least one second region of the packaging member or of the machine with an oxidizing agent. The first region and the second region overlap at least in part. The method may also include visually inspecting at least one intersection region, which has been acted upon both with the oxidizable medium and with the oxidizing agent.