Tips for the Proper Use of Fume Hoods
- The gas cabinet should not be used as a storage unit.
- Place only the materials necessary to perform the task at hand inside the workstation, and avoid placing unnecessary materials that could hinder the workstation’s proper functioning or require unnecessary arm movements.
- Place operations that generate contamination at a distance of no less than 15 or 20 cm from the opening plane of the fume hood.
- Prevent the generation of pollutants at high speeds.
- Position the area where pollutants are generated as low as possible to facilitate the exhaust of pollutants through the lower opening of the rear deflector.
- Prevent obstruction of airflow to the rear deflector.
- Use only the minimum amount of product necessary.
- Limit heat sources to the minimum necessary, as they interfere with the display case's air intake.
- Reduce the opening to the minimum space necessary for the task at hand, and always keep it below the maximum operating height. Do not put your head inside the display case.
- Do not operate the display case with the vertical and horizontal windows open at the same time, if applicable.
- Move slowly to avoid turbulence.
- Wear appropriate protective clothing and equipment (goggles, lab coat, gloves).
- If you detect a problem with the exhaust system, close the sash and report the situation to the appropriate person (laboratory supervisor, maintenance manager, safety officer, etc.). Do not use the fume hood, and mark it appropriately as out of service or malfunctioning.
After use:
- Leave the display case clean and tidy.
- Close the guillotine and let it run until the contamination has been removed.
- Work must be performed at least 15 cm away from the hood frame.
Keep in mind that:
- The fume hoods draw in and exhaust the conditioned air from the laboratory, resulting in a significant energy cost.
- They do not ensure the operator's protection against microorganisms and contaminants present in the laboratory.
Maintenance of Display Cases
- The display case must have a preventive maintenance program in order to extend its service life and ensure operator safety.
- Follow the manufacturer's or supplier's instructions, and the entire system—from the display case inlet to the exhaust duct—must undergo periodic inspections, with the date of the last inspection recorded and noted.
- For display cases equipped with filters, it is very important to verify that the filters are suitable for the chemicals being used and to check their saturation level as often as necessary, depending on their use and characteristics.
Tasks recommended on a weekly basis:
- Check the operation of the flow indicator and its alarm, if applicable.
- Cleaning the inside of the display case.
Tasks recommended on a semi-annual basis:
- Cleaning the rear deflector.
- General cleaning of the inside of the deflector chamber using a diluted detergent solution.
- Inspect the guillotine's operating mechanisms.
Annual Tasks:
- Visualization of air currents.
- Exhaust Control (measurement of air velocity in the guillotine plane or exhaust flow rate).
- Thorough inspection of the guillotine's operating mechanisms.
- Visual inspection of the extraction duct and its accessories; inspection of the vacuum equipment.
- Noise Level Control.
- Lighting level.
- Inspection of the condition of the fluid systems associated with the display case.
Tasks to be performed as needed:
- If a problem is detected with the vacuum systems, they must be inspected.
- If the user deems it appropriate, the behavior of the gas display cabinet can be studied in greater depth by analyzing its containment and other relevant parameters on site.
For more information, see NTP 677:“Laboratory Safety. Laboratory Fume Hoods: Use and Maintenance”at the following link: http://goo.gl/n4TQJv and NTP 672: Local Exhaust Ventilation in the Laboratory: http://goo.gl/EYJMiK