A Tale of Two Sterilizers

Steam sterilization is widely used across the healthcare industry and is the most documented and standardized sterilization method. Despite its broad application, there is considerable confusion regarding the different process control considerations and sterilizer designs necessary for its successful use. The methods and equipment used for porous loads (equipment, components, and tools) are established to address air removal and steam penetration as these are critical to process efficacy. Sterilizing processes and equipment for non-porous loads (sealed aqueous containers) seek to minimize variations across the load and minimize the potential for under- or over-processing of portions of the load. These distinctions are not always evident in publications. The United States Pharmacopeia content brought attention to these differences in General Chapter <1229.1> Sterilization by Direct Contact and General Chapter <1229.2> Moist Heat Sterilization of Aqueous Liquids. This publication provides expanded content beyond that found in USP in a side-by-side comparison of the process considerations and equipment design details. It also reviews sterilization practices in laboratory, formulation, and biowaste sterilization applications, which often require the simultaneous sterilization of porous and non-porous items.