Once they have initially been placed on the market within the EU, such safety components are the responsibility of the operator and therefore, like all work equipment, fall under the scope of the EU Use of Work Equipment Directive 2009/104/EC, implemented in Germany as the industrial safety regulations (BetrSichV). § 10, Paragraph 1 of BetrSichV, "Inspection of work equipment" states the following:
(1) The employer shall ensure that where the safety of work equipment depends on the installation conditions, it shall be subjected to an inspection after installation and before first being put into service. The purpose of this inspection is to ensure that the work equipment has been installed correctly and is operating safely. This inspection shall only be carried out by competent persons in the respective field.
In other words, you may use the components, but you must ensure that they conform to the state of the art, operate safely and are installed correctly.