A publication by Julia Homer (Labor LS) and Dr. Frank Mertens was recently featured in the trade journal cleanroom & processes (issue 4/2025), addressing an often underestimated risk in aseptic manufacturing: filterable microorganisms.

Even intact and validated sterilizing-grade filters may allow microbial passage under certain conditions. These so-called filterable bacteria challenge the widely held assumption that sterilizing filters always represent the final and fully reliable safety barrier in aseptic processes.

The article explains the biological mechanisms behind this phenomenon, presents examples of filterable microorganisms, and discusses strategic approaches for risk assessment and risk mitigation in aseptic manufacturing processes.

The aim of the publication is to raise awareness of microbiological risks beyond the human factor and to deepen the understanding of contamination control in aseptic production.

The full article is available upon request.