This session provides a detailed look at how contaminants can infiltrate a cleanroom and persist, even during the controlled processes of cleanroom certification. We’ll follow the journey of an organism as it travels through the environment, from initial entry via personnel, materials, or equipment, to its movement within the space during certification activities. The talk will explore how these contaminants are eventually detected through environmental monitoring and trending. We’ll also cover practical remediation strategies and process improvements to eliminate contamination and reduce the risk of recurrence.