The operating instruction according to the technical rules for hazardous substances (TRGS) 555 is a document that contains hazards and the handling of hazardous substances that are present or arise at the corresponding workplace. In addition, company-specific instructions are also specified. The aim here is to make information available to employees in an understandable written form and language. The employer is responsible for the preparation and provision of operating instructions. When an operating instruction is required and in what form it is to be made available is described in the ordinance on hazardous substances and the corresponding TRGS 555.