Precautions for using fume hoods

Precautions for the use of fume hoods

Laboratory fume hood is a kind of large-scale equipment in laboratories, especially chemical laboratories. The purpose is to reduce the exposure of experimenters and harmful gases.

Before use

The operator can start using the fume hood after activating the roof fan system, and should inspect the fume hood before using it.

1. Whether the power switch is in the open position.

2. Whether the fluorescent light switch is turned on.

3. Whether the fume hood is in the exhaust state.

When the results of the inspection are all right, the fume hood can be operated.

When in use

1. When the experimenter is in the fume hood experiment, he should not put his head into the adjustment door to avoid danger. The abdomen and chest are 10-15cm away from the fume hood adjustment door.

2. Do not pull the fume hood door too high during and after the experiment. Door placement too high reduces contaminant capture, increases leakage rates, exposes the operator's face to contaminants, and increases energy consumption.

3. Generally, the air inlet inside the fume hood is at the innermost and top side, so the closer the contaminant is to the inside, the higher the capture rate of the fume hood. When the experimenter is operating the experiment that produces smoke or emits gas, it should be carried out at least 20cm away from the fume hood door.

4. When large equipment needs to be used, or the height of the equipment is more than 10cm, there needs to be an airflow channel under the equipment, and the equipment can be raised about 10cm by using a stainless steel bracket.

5. Avoid placing too much equipment and instruments in the fume hood, and the total area of equipment or other equipment in the fume hood shall not exceed 50% of the area of the countertop.

6. If the fume hood is close to the door and window, the doors and windows should be closed when the fume hood is used, and the fan should not be turned on near the fume hood to reduce the interference of the ambient airflow as much as possible.

7. When contaminants begin to form in the fume hood, the operator must slowly approach or leave the fume hood. This is because rapid movement will cause airflow disturbances near the front opening of the fume hood and bring out the contaminants in the cabinet.

After use

1. Make sure the fume hood is clean and clean.

When a fume hood has been treated with highly toxic, residual or radioactive substances, the inside of the fume hood should be cleaned and decontaminated immediately. Contaminated fume hoods should be marked with a clear warning sign and inform maintenance personnel which piping systems may be contaminated to avoid injury to maintenance personnel.

2. No items can be stored in the fume hood.

Laboratory fume hoods should not be used as a substitute for chemical storage cabinets, as fume hoods can degrade performance due to excessive storage and reduced effective workspace.

3. When not working, make sure that the glass window (adjustable door) is closed.