It is evident that rubber in the food or pharma industry has completely different requirements than rubber used in construction or car tyres. While some common techniques are undoubtedly used in the evaluation of the compounds, such as hardness, tensile strength or modulus, a very important additional concern for pharmaceutical rubber or rubber in contact with food, is the cleanliness. First of all, the chemical cleanliness is essential. Since this rubber can be in long-term contact with food or drugs, it is critical that no hazardous substances are leaching out of the rubber. Under the motto “what you don’t put in, can’t come out”, these compounds generally contain as little and as pure ingredients as possible. Second, the particulate cleanliness is a concern as well, especially for pharmaceutical applications. As little particles as possible should be present on the rubber parts, e.g. to avoid any of these particles getting into the drug. To this end, many precautions are taken to obtain a very clean production environment, and highly controlled cleanrooms are used for the most critical applications. Consequently, not only the final products, but also the production area can have a completely different look depending on the envisaged application for the rubber.