Without validated cleanability, you will never be able to sterilise a plant or reliably place your products on the market. A whole plant is more than the sum of its single parts. Even if you use certified components for construction a lot of hygienic critical effects are likely to occur. Hygienic testing of plants is mandatory before use and – much more critical – after years of production. During operation biofilm colonies were unintentionally promoted which resist the established cleaning and sterilisation procedures. Every food plant has got its own bacteriological biosphere. Therefore, adapted methods for cleaning/sterilisation validation need to be installed. 

Finding microbiologic problems is possible with a manageable amount of technical and organisational efforts. These methods are in use for the validation of aseptic filling machines. For other sections of a plant these methods need to be modified. The results are clear and reliable for detecting recontaminations down to 10-9 cfu/ml. For the location of problems plants need to be checked in separate sections. It makes sense to validate non-aseptic plants to qualify improvements or changes in construction. The detection of non-bacteriological soil is difficult and not reliable because it is unlikely to flush out CIP-unremovable soil. Accessibility is seldom given for direct surface testing methods (EPS-coloration). Therefore, tailored differential methods should be used to choose the one which leads to the most striking results. In several bachelor professional studies, the effectivity of some testing methods where quantified on pilot plants. You need to determine the best option for your plant through trial and error.