Effect of Gamma-Ray Irradiation and Surface Scratching on the Passivation Layer of Stainless Steel Components in Single-Use Systems

The objective of this study was to determine the effect of several factors present in the manufacturing and distribution of type 316L stainless steel components used in drug processing, as these factors may harm the component’s passivation layer. Understanding this layer’s weak points is critical as its failure can result in component corrosion and lead to product contamination. The factors examined in this study are the processing techniques used by different manufacturers, exposure of components to gamma-ray irradiation, and the introduction of surface scratches. Gamma-ray irradiation was considered because single-use systems and their components are required to be irradiated to help sterilize them prior to use. Surface scratches were considered as it is believed that the components may come in contact and scratch each other during shipping. An experiment was devised where components from different manufacturers were either irradiated or non-irradiated and had scratches applied using different materials. These components were then subjected to accelerated aging and inspected for evidence of the passive layer’s failure in the form of corrosion products. Observations of corrosion products were compared between samples to investigate the impact each of these experimental factors played in the degradation of the sample’s passivation layer. Among the factors considered, stainless steel-scratched and control samples appeared to show corrosion products more ofte