Aseptic filling of biopharmaceutical products requires a grade A cleanroom environment, preferably ensured by isolators in grade C surroundings. Isolators are decontaminated before the start of filling processes using vaporized hydrogen peroxide (VHP) and filling starts at pre-defined residual VHP levels (e.g., below 0.5 ppm) depending on product sensitivity towards VHP oxidation. Manufacturing equipment and consumables, including filling assemblies, are exposed to VHP during or after the decontamination cycle or after line interruptions. We studied the VHP uptake by tubing in a lab-scale model isolator to evaluate the impact of tubing properties including contact material, tubing dimensions, suppliers, and VHP exposure (concentration and exposure time). Quantifying the release of H