A vertical laminar flow hood is a specialized enclosure designed to create a particle-free working environment by continuously filtering air. It functions by drawing air through a High-Efficiency Particulate Air (HEPA) filter, which removes airborne contaminants. This filtered air then flows vertically downwards over the work surface and exits the hood, providing a sterile area for sensitive tasks. This article provides guidance on how to clean a vertical laminar flow hood, ensuring its proper function and the integrity of your work.
Why Cleaning is Essential
Regular cleaning of a vertical laminar flow hood maintains its sterile environment and protects sensitive work. Contaminants like dust, skin cells, and microorganisms can settle on surfaces, compromising experiments if left unaddressed.
Accumulated debris can affect the hood’s operational efficiency. Particles can obstruct airflow, reducing the HEPA filter’s effectiveness and the sterile air curtain. A clean hood ensures the controlled environment remains suitable.
Maintaining cleanliness contributes to sample integrity and reliable results. Without a consistently clean workspace, there is an increased risk of cross-contamination, which can invalidate research outcomes. Regular cleaning protects both the work and the equipment.
Gathering Your Cleaning Supplies
Before cleaning, gather necessary supplies for safety and effectiveness. Personal protective equipment (PPE) is a priority, including disposable gloves and eye protection, to guard against splashes and cleaning solutions.
Appropriate cleaning solutions are used for decontamination. Common choices include 70% ethanol or 70% isopropyl alcohol, effective against many microorganisms. Choose solutions that evaporate cleanly and do not leave residues.
Lint-free wipes or cloths are used for cleaning surfaces without introducing new particles. Standard paper towels can shed fibers, contaminating the clean environment. Lint-free materials maintain the sterile workspace’s integrity.
The Cleaning Process
Turn off the hood’s blower motor and allow air to clear for a few minutes to remove airborne particles. Carefully remove all items, including equipment and samples, from the work surface.
Once clear, wipe surfaces systematically to prevent recontamination. Start with the highest internal surfaces, such as the top panel, and work downwards toward the work surface. Use overlapping strokes for complete coverage.
Apply the cleaning solution, such as 70% ethanol or isopropyl alcohol, to a lint-free wipe; do not spray directly into the hood. Wipe all interior walls, including the side panels, and the entire work surface. For disinfectants requiring a specific contact time, allow the solution to remain on the surface for the recommended dwell time before wiping dry or evaporating.
Exercise caution around the HEPA filter grille, wiping only the grille without touching the delicate filter material. The HEPA filter should never be wetted or directly cleaned, as this can damage its filtration capabilities. After cleaning, dispose of all used wipes and gloves according to laboratory waste protocols.
Maintaining a Clean Environment
Establish a regular cleaning schedule to maintain a consistently clean laminar flow hood. Cleaning frequency depends on usage intensity and work sensitivity, but daily cleaning is often recommended for active hoods. Routine inspection for visible dust or spills helps determine when additional cleaning is necessary.
Proper user habits contribute to ongoing cleanliness and reduce intensive cleaning needs. Minimize clutter within the hood and avoid rapid movements to prevent particle generation and dispersal. Practicing aseptic technique when handling materials reduces contaminant introduction.
Avoid placing items directly against the back or side walls of the hood, as this disrupts airflow. Regularly check pressure gauges or indicators for potential filter issues. Adhering to these practices preserves the sterile environment.