A laminar flow hood is a carefully enclosed bench designed to prevent the contamination of semiconductor wafers, biological samples, or any particulate-sensitive materials. Air is drawn through high-efficiency particulate air (HEPA) filter and blown in a very smooth, laminar flow toward the user.
Purposes
- To provide clean air in the working area
- To provide a constant flow of air out of the working area to prevent room air from entering
- To suspend and remove contaminants from the working area
What It Does
- Draws in room air and passes it through HEPA filters to remove 99.97% of particles ≥0.3 microns.
- Delivers unidirectional airflow (either vertical or horizontal) across the work surface to sweep away contaminants.
- Maintains a positive pressure zone to prevent room air from entering the sterile field.
Clinical Applications in Neonates
| Use Case | Purpose |
|---|---|
| Medication preparation | Ensures aseptic technique for IV drugs, TPN, or antibiotics |
| Handling central lines or catheters | Reduces infection risk during insertion or dressing changes |
| Caring for immunocompromised neonates | Provides a cleaner microenvironment for vulnerable infants |
| Research or diagnostic procedures | Maintains sterility for sample handling or genetic testing |
Mode of Action
The laminar flow hoods take in room air and pass it through a prefilter to remove the dust and other contaminants. Then the air is compressed and channelized through the HEPA filter in a laminar flow fashion, that is, pure air flows out over the entire work surface in parallel lines at a uniform velocity.
Types
Based on the direction of airflow, laminar flow hoods are divided into two types:
- Vertical laminar flow hoods: Air flows from top to bottom; safer for handling hazardous substances.
- Horizontal laminar flow hoods: Air flows from back to front; often used for general aseptic procedures.
Advantages
It is one of the most effective methods for reducing the incidence of infection associated with medication administration. The HEPA filter removes nearly all bacteria from the air.
Disadvantages
- There is a chance to reintroduce contaminants into the working area if the correct technique is not followed.
- It must be on 24 hours a day to maintain its purpose.
Guidelines
- If the equipment is switched off for any reason, it must be switched on within half an hour.
- It also should be cleaned thoroughly before reusing
A direct path must be maintained between the filter and the area inside the hood
Special Considerations
- Must be on continuously to maintain sterility.
- If turned off, allow 30 minutes of airflow before reuse.
- Clean with 70% isopropyl alcohol before and after use.
- Avoid blocking airflow with large objects—maintain a direct path between HEPA filter and sterile field.
- The hood must remain on 24/7 to maintain a sterile field; if turned off, allow 30 minutes before reuse.
REFERENCES
- Annamma Jacob, Rekha, Jhadav Sonali Tarachand: Clinical Nursing Procedures: The Art of Nursing Practice, 5th Edition, March 2023, Jaypee Publishers, ISBN-13: 978-9356961845 ISBN-10: 9356961840
- Omayalachi CON, Manual of Nursing Procedures and Practice, Vol 1, 3 Edition 2023, Published by Wolters Kluwer’s, ISBN: 978-9393553294
- Sandra Nettina, Lippincott Manual of Nursing Practice, 11th Edition, January 2019, Published by Wolters Kluwer’s, ISBN-13:978-9388313285
- Marcia London, Ruth Bindler, Principles of Paediatric Nursing: Caring for Children, 8th Edition, 2023, Pearson Publications, ISBN-13: 9780136859840
- Naveen Bajaj, Rajesh Kumar, Manual of Newborn Nursing, 2nd Edition, 2023, Jaypee Publishers, ISBN:978-9354659294
- Ernstmeyer K, Christman E, editors. Nursing Fundamentals [Internet]. 2nd edition. Eau Claire (WI): Chippewa Valley Technical College; 2024. PART IV, NURSING PROCESS. Available from: https://www.ncbi.nlm.nih.gov/books/NBK610818/
Stories are the threads that bind us; through them, we understand each other, grow, and heal.
JOHN NOORD
Connect with “Nurses Lab Editorial Team”
I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.
