What Are The Key Points for Using A Fume Hood in A Biological Laboratory in Microbiological Experiments?

The key points for using fume hoods in biological laboratories in microbiological experiments are as follows:

Check before use

Check whether various switches and pipelines such as power supply, water supply and drainage, and gas are normal. Turn on the lighting equipment to check if the light source and the interior of the cabinet are normal. Turn on the exhaust fan and listen quietly to see if it operates normally. Regularly check the monitor and promptly eliminate any faults found.

Check whether the sliding door window is intact, whether the face velocity of the fume hood is within the normal range, and whether there is an alarm message on the screen.

Operators should use appropriate personal protective equipment. If there is a possibility of explosion, protective face shields should be used.

Operating Specifications

Window adjustment: It is advisable to open the operation window 100-150mm away from the tabletop. In critical moments, it can serve as a barrier. The glass window is only allowed to be opened to the highest state when assembling, debugging the internal instruments and equipment or cleaning the space inside the cabinet. This is the "debugging state". Open the glass window to the user's elbow (half open), allowing the operator to reach into the cabinet to conduct experiments, while the area above the chest is protected by the safety tempered glass of the glass window. This is the "normal operating state". Open the adjustment door to the minimum opening, and the operator leaves to allow the experimental program inside the cabinet to react automatically or pause the experiment. This is the "standby state".

Personnel behavior: It is strictly prohibited to insert your head into the fume hood during the experiment for operation or inspection. When pollutants start to form inside the fume hood, the operator must approach or leave the fume hood slowly to avoid rapid movement that may disturb the airflow near the front opening of the fume hood and carry out the pollutants inside. In front of the fume hood, the operator should also avoid rapidly waving their arms and moving their positions.

Item placement: Equipment and chemical substances should be placed in the center of the partition close to the back of the fume hood. Too many items and equipment should be avoided in the fume hood to prevent interference with the normal flow of air and cause turbulence. Generally, no items should be placed within 15cm of the left and right side walls and the cabinet door opening. Experimental equipment should be prioritized to be placed deep inside the fume hood, maintaining a distance of 15cm to 20cm from the front window. When the height of the placed equipment exceeds 10 centimeters, there needs to be an air flow channel beneath the equipment. This allows the equipment's support feet to raise the equipment, thereby reducing interference with the air flow pattern. It is necessary to avoid placing too many equipment and instruments in the fume hood. The total area of equipment or other devices in the fume hood should not exceed 50% of the countertop area. When using instruments inside the fume hood, it should be noted that the equipment should be grounded to reduce the possibility of sparks. The power cord should be pulled out from the air inlet at the bottom and connected to an external power socket. The power socket should also have a complete and certified grounding facility.

Other precautions: Supply air for 10 minutes every 2 hours (i.e., open Windows for ventilation). If the usage time exceeds 5 hours, keep the Windows open to prevent negative pressure in the room. Do not place power strips or wires in the fume hood. Cut off the power in case of danger. Biological experiments are prohibited in the fume hood of the chemistry laboratory. It is prohibited for fume hoods to conduct experiments involving substances prohibited by the state for emission. Do not use the sink of the fume hood as the garbage disposal area. When the fume hood is not in use, the operator should avoid storing too many test equipment or chemical substances on the countertop of the fume hood and must not stack them for a long time.

Post-use processing

Before shutting down, it should be run continuously for several minutes to ensure that all exhaust gases are completely discharged. After using the fume hood, the inside and outside of the cabinet should be wiped clean, and all switches and Windows should be turned off.

Before leaving the fume hood, the operator should turn off all water, electricity and gas switches and lower the window to the lowest position before leaving.

When a fume hood has handled highly toxic, highly residual or radioactive substances, the interior of the fume hood should be immediately cleaned to remove contamination. A clear warning sign should be hung on the contaminated fume hood, and the maintenance personnel should be informed of which pipeline systems may be contaminated to avoid injury to the maintenance personnel.

Maintenance and upkeep

To extend the service life of the fume hood, proper cleaning and maintenance should be carried out. If reagents or chemicals splash, they should be wiped and removed in time. Before leaving work every day, the interior should be wiped clean with clean water. The deflector plate should be disassembled and cleaned every quarter and its integrity checked.

The accessories mainly include hinges, screws, handles, etc. Their materials are generally stainless steel or steel surfaces treated with plating or plastic spraying. When in use, direct contact with salt, acid, alkali and other chemicals or reagents should be avoided. If it occurs accidentally, clean with clean water and wipe dry with a dry cloth. Door hinges should be oiled regularly and protected from long-term moisture.

Keep the sewer unobstructed and prevent blockage. The connection between the sink and the countertop should be kept clean. If there are water stains, they should be wiped dry with a cloth. Pay attention to the service life of materials such as hoses and sealing materials to prevent leakage and the expansion of the contaminated area.