Indispensable equipment for laboratories, fume hoods protect personnel from exposure to chemicals handled during experiments. Fume hoods ventilate the hazardous and noxious chemicals, vapors, gases, or dusts released during experiments. Sample protection is another important advantage of fume hoods. Fume hoods may either be ducted or recirculating. Both types operate by allowing air to be drawn in from the front (open) side of the cabinet, and either expelled outside the building or made safe through filtration and recirculated back into the room.
We recently surveyed a select group of our readers on fume hood use in their labs.
Maintenance
Fume hoods cannot protect lab personnel without scheduled maintenance to keep them operating properly. The most critical part to maintaining hood performance is a regular check or testing of fume hood flows. Routinely checking the hood for adequate flow and velocity must be incorporated into your lab safety program. Vendors recommend labs post flow test results or performance checks directly on the hood and request a recheck if they suspect a problem.
Fume hood inspection and periodic maintenance
Annual fume hood maintenance
Exhaust fan maintenance: Lubricate moving parts, check belt tension, inspect fan blade for deterioration, and record rpm— according to the manufacturer’s recommendations.
Most of our surveyed readers inspect their fume hoods at least every year. Here’s what they had to say about how frequently they inspect the fume hoods in their labs:
| Monthly | 12% |
| Quarterly | 12% |
| Every six months | 16% |
| Annually | 47% |
| Every two years or more | 5% |
| Not applicable | 2% |
| Don’t know | 7% |
Design location principles for fume hoods
Layout of the laboratory and location of the fume hood is very important for optimum performance and minimal interference. Fume hoods must not be located near doorways or exits. Ten feet from any door or exit is recommended by the National Fire Protection Association. Also, to the greatest extent possible, locate fume hoods away from high-traffic areas, air supply diffusers, doors and windows. Any area that produces air currents or potential turbulence could affect the ability of the hood to capture and exhaust contaminates as designed. Do not locate fume hoods opposite workstations, desks, microscope benches or other areas where personnel spend significant time. Ensure that there is an emergency eyewash and safety shower within ten seconds of every fume hood. This is a requirement wherever a worker could be exposed to corrosive, toxic or severely irritating substances.
Safety is clearly a priority with our readers, as shown by their responses to these fume hood safety statements:
| Agree | Disagree | Don't Know | |
| All fume hoods have been tested within the past year. | 87% | 10% | 3% |
| Test labels are properly affixed to the fume hoods tested. | 80% | 16% | 4% |
| Storage in fume hoods is kept to a minimum and is placed so as to not impede proper airflow. | 91% | 6% | 2% |
| To maximize hood effectiveness and minimize personnel exposure to toxic vapors or gases, our lab uses fume hoods in accordance with the operational guidelines. | 92% | 2% | 5% |
The top ten most important factors for our respondents in their decision to buy a fume hood:
| Durability of product | 95% |
| Ease of use; ergonomic operation | 95% |
| Low maintenance / easy to clean | 92% |
| Low operating costs | 89% |
| Performance of product | 100% |
| Safety and health features | 92% |
| Service and support | 78% |
| Total cost of ownership | 79% |
| Value for price paid | 92% |
| Vendor reputation | 73% |
Conventional ducted fume hoods are the most popular with our surveyed readers, with benchtop ductless fume hoods a distant second. Here is the breakdown of the types of fume hoods respondents are using:
| Benchtop ductless fume hood | 16% |
| Canopy ducted fume hood | 11% |
| Conventional ducted fume hood | 58% |
| Down flow workstation | 5% |
| Portable ductless fume hood | 2% |
| Variable air volume ducted fume hood | 8% |
| Other: | 1% |
For more information about fume hoods, please visit www.labmanager.com/fume-hoods
