Assessing the Relative Cleanabilities of Bioprocess Soils

Bench-scale methods for assessing the relative cleanabilities of process soils are useful tools for applying risk-based approached to full-scale cleaning validations, troubleshooting cleaning issues and developing cleaning strategies. In this study, a spreading method for controlling soil size and shape during sample preparation and an image-analysis technique for constructing “cleaning profiles” from which relative cleanability may be determined were explored.  Variables useful for studying spreading and cleanability were defined – Spreading Ratio (SR) and Specific SR (SSR), which quantify surface-area coverage and average area density, respectively. Using these methods, strategies for comparing soil spreading on various materials of construction and determining relative cleanabilities among larger groups of soils are presented.