Quality assurance as a general responsibility of the entrepreneurs practically involves all sectors of the industry and covers right - from the planning stage through to the material purchase and production right up to the final stage of product control. Quality assurance system and quality assurance measures for production and product control have meanwhile became a common item in the rubber industry. The subjects of the WdK guidelines series 1000 ff (and following) relate to the quality assurance of raw materials. By quality assurance of raw materials it is not meant the assurance of peaks of property levels but more the assurance of consistency of the property levels. The motive is towards reduction and minimisation of variations of property values with due considerations to certain economic aspects and factors.