Contamination control has received great interest and found increasing use within several industrial branches including microelectronics, pharmaceuticals, food and beverages using various concepts of contamination control in their production, purification or packaging process. The book supplies a holistic view of contamination control, presenting the different types of contaminants in a summarized form. The focus is on how to protect products and processes from external contamination and also on different ways to take care of and control contaminants generated in the process. The aim is to eliminate them from a product or a process flow (e.g. through filtration), or to render them harmless (e.g. through sterilisation by moist heat). Product purity or the cleanliness of process flows are often complex matters and hard to define in easily understood terms. This book covers a variety of different techniques used in order to achieve and maintain certain overall cleanliness levels for both microbiological or inanimate particle contaminants. It supplies basic knowledge including validation aspects for industrial branches working with increased demands of cleanliness, for instance water purification, steam, pressurized gases and different flows in a process together with finished products.