RoHS (Restriction of Hazardous Substances) means the prohibition of harmful substances. This means that some toxic / harmful materials may no longer be used in electronic equipment (think of lead, mercury, chromium, cadmium, etc.). These substances are dangerous for the environment and for the people who work with them. The law has entered into force in the EU since July 1, 2006. Since then, all mass products have been soldered lead-free.