An effective contamination control strategy should address not only the use of process aids such as silicone oil, but also their removal from direct, indirect and non-product-contact surfaces. Residual silicone oil on equipment components such as stopper bowls, transfer chutes and star wheels can create visible or tacky surfaces that may increase particulate and microbial contamination risks.

In this article, members of our dedicated scientific team, Sarah Riley, Cecilia Pierobon, Dijana Hadziselimovic and Paul Lopolito present the results of controlled laboratory studies designed to evaluate silicone cleaning performance. The research examines the impact of key cleaning variables, including cleaning agent selection, concentration, temperature, contact time, soil load and dirty hold conditions. They also assess analytical approaches such as visual residue limit testing and Fourier-transform infrared (FTIR) spectroscopy for detecting residual silicone oil on stainless steel surfaces.

The findings provide manufacturers with a practical, science-based framework for optimizing cleaning processes, supporting residue limit development and strengthening contamination control programs for indirect surfaces used in aseptic manufacturing.