Corrosion Susceptibility of Surgical Stainless Steels in Instrument Reprocessing for LMICs: Influencing Factors and Accelerated Testing

Abstract

This study investigates surgical stainless steels 304, 410, and 420 corrosion susceptibility under manual reprocessing conditions typical of low- and middle-income countries (LMICs). Cleaning protocols using sodium hypochlorite and the enzymatic agent Sanizyme were compared alongside an accelerated Salt Mist Test to explore predictive value for corrosion. Results show that sodium hypochlorite causes rapid corrosion across all steel types. In contrast, Sanizyme significantly delays corrosion onset and reduces the affected surface area, with stainless steel 304 demonstrating the most outstanding resilience. Minor differences between 410 and 420 were observed, with no significant performance distinction.
Including 2-hour rest periods, intended to activate stainless steel’s self-healing properties, did not significantly impact corrosion resistance. Additionally, the Salt Mist Test showed limited correlation with corrosion development observed under manual reprocessing conditions, indicating the need for refined predictive methods. These findings suggest that gentler enzymatic cleaning protocols enhance the longevity of surgical instruments in LMIC contexts, while accelerated corrosion tests may require adjustments to simulate clinical reprocessing better.