Laboratory fume hoods are vital equipment in any lab where chemicals are used. Their main role is to protect lab personnel from inhaling hazardous vapors, gases, or dust by drawing them away from the user and venting them outside or through filters. However, even the best fume hoods will not function properly without regular maintenance.
Proper maintenance ensures not only the safety of lab workers but also the efficiency and longevity of the equipment. If a fume hood fails, it could lead to serious health risks, compliance issues, or costly repairs. That’s why routine inspection, cleaning, and testing are crucial. In this article, we will explore the essential maintenance practices for laboratory fume hoods, written in easy-to-understand language and optimized for search engines.
1- Why Maintenance of Laboratory Fume Hoods Is Important
Before diving into the practices, it’s important to understand why maintenance matters. A well-maintained fume hood:
- Protects users from exposure to toxic chemicals.
- Helps laboratories meet safety regulations and standards (such as OSHA, ANSI, or ASHRAE guidelines).
- Improves the energy efficiency of the lab.
- Prevents unexpected breakdowns or expensive replacements.
- Extends the lifespan of the equipment.
Whether you’re managing an academic, industrial, or pharmaceutical laboratory, regular maintenance is key to safe and smooth operations.
2- Regular Visual Inspections
One of the easiest yet most critical maintenance tasks is visual inspection. This should be done at least once a month, or more often in high-use environments.
What to Look For:
- Cracks or damage in the sash (the movable glass window).
- Any visible wear and tear on the hood interior.
- Blockages or obstructions in the airflow.
- Dust buildup or spills.
- Proper function of lights and alarms.
During inspection, always check that the sash moves smoothly and stays in position, and that there are no loose or broken parts.
3- Airflow Monitoring and Face Velocity Testing
The performance of a fume hood depends heavily on its airflow. Testing the face velocity (the speed at which air enters the hood) ensures that fumes are being properly drawn in.
Recommended Practice:
- Conduct face velocity testing at least once every 6 to 12 months.
- Ensure airflow stays between 80-120 feet per minute (fpm) for most general-use fume hoods.
- Use an anemometer or airflow meter for accurate results.
- Install a continuous airflow monitor or alarm if the hood is used regularly.
Poor airflow may indicate issues with the building’s HVAC system or a clogged duct. Always address abnormal readings immediately.
4- Filter Replacement and Cleaning
Fume hoods come in two types: ducted and ductless (or filtered). In ductless hoods, filters are essential for trapping harmful fumes before releasing air back into the lab.
Maintenance Tips:
- Replace carbon filters and HEPA filters according to the manufacturer’s guidelines (usually every 6–12 months).
- If your hood has pre-filters, check and clean them monthly.
- Dispose of used filters properly, especially if they contain hazardous substances.
For ducted hoods, although filters are not always used, the ductwork should still be inspected and cleaned periodically to prevent clogs or corrosion.
5- Sash and Glass Cleaning
The sash should always be clean and clear for proper visibility and operation. A dirty or scratched sash can affect airflow and compromise safety.
Cleaning Procedure:
- Use a mild, non-abrasive cleaner and a soft cloth.
- Avoid using strong solvents that could damage the glass or plastic.
- Wipe down the edges, tracks, and handles as well.
Keeping the sash clean also helps maintain a professional, organized lab environment.
6- Mechanical and Electrical Component Checks
Fume hoods have several moving and electrical parts that should be checked regularly:
- Fans and blowers: Ensure they’re running smoothly without noise or vibration.
- Lights: Replace any burned-out bulbs and check wiring.
- Alarms and monitors: Test regularly to ensure they’re working correctly.
- Switches and buttons: Ensure full functionality without sticking or delay.
Any signs of mechanical wear or electrical faults should be reported and fixed by qualified technicians.
7- Calibration and Certification
Professional calibration and certification are required to ensure your fume hood complies with safety standards. This includes checking airflow rates, exhaust performance, and sash operation.
Frequency:
- Certification should be performed at least annually by certified professionals.
- More frequent testing may be required in high-risk labs or if the hood is used intensively.
Fume hood manufacturers usually provide specific calibration guidelines. Be sure to follow them strictly and keep records for audit purposes.
8- User Training and Awareness
Even with perfect equipment, improper usage can lead to safety hazards. That’s why it’s essential that every lab user is trained on:
- How to operate the fume hood properly.
- What chemicals can or cannot be used in the hood.
- How to read airflow monitors and alarms.
- Basic troubleshooting and maintenance alerts.
Display user instructions and safety signs near the fume hood to remind users of proper procedures.
9- Documentation and Maintenance Logs
Keep a record of all maintenance activities. This includes:
- Dates of inspections and filter changes.
- Calibration results.
- Repairs or part replacements.
- Certification and performance test reports.
This documentation helps in tracking hood performance over time and ensures regulatory compliance.
10- When to Call a Professional
While many maintenance tasks can be handled in-house, certain issues require expert help:
- Strange noises or smells from the hood.
- Poor airflow even after cleaning.
- Damaged ductwork or electrical systems.
- Any problems you are unsure how to fix.
Always consult your fume hood manufacturer or a certified lab equipment technician for complex repairs or testing.
Conclusion
Maintaining your laboratory fume hoods is not just about following safety rules — it’s about protecting lives and ensuring efficient lab operations. Regular inspections, filter replacement, airflow testing, and user training are all part of an effective maintenance routine. By staying proactive, you can avoid costly downtime, meet safety standards, and create a safer working environment for everyone.
Whether you’re running a school lab, pharmaceutical research center, or industrial facility, don’t overlook fume hood maintenance. Make it a priority — your team’s safety depends on it.