Cleaning validation receives a great deal of attention within the biopharmaceutical industry, not least because of the risks of product adulteration and hence patient harm from improperly cleaned surfaces (notwithstanding additional concerns such as operator protection). Traditionally, cleaning validation efforts focus on direct product-contact surfaces. However, the hazard and resultant risk posed from indirect product-contact surfaces should not be underestimated. Consideration of the risks presented by indirect surfaces should figure into every contamination-control strategy. Understanding of these risks cannot be…