Views: 0 Author: Site Editor Publish Time: 2025-06-20 Origin: Site
When using fume hoods for experiments containing radioactive substances, the following safety regulations must be followed:
When conducting experiments involving radioactive substances or perchloric acid, etc., a dedicated fume hood should be selected, and its intake air velocity must be set to be greater than 0.5m/s. Ordinary fume hoods cannot be used for experiments involving perchloric acid and radioactive substances. Perchloric acid vapor can crystallize in pipelines, leading to the accumulation of high aluminates and subsequently causing explosions, which can seriously harm laboratory researchers and maintenance personnel. The dedicated perchloric acid type fume hood is made of stainless steel and is equipped with a dedicated spray cleaning system. Radioactive fume hoods must prevent the accumulation of radioactive substances inside the fume hood to facilitate cleaning.
Reasonable layout of equipment: When conducting experiments with large-scale equipment, the effective internal dimensions should be taken into account, and necessary space should be reserved for exhaust. When large equipment is needed or the height of the placed equipment exceeds 10cm, there should be air flow channels under the equipment. Stainless steel brackets can be used to raise the equipment by about 10cm. Excessive equipment and instruments should be avoided from being placed in the fume hood. The total area of equipment or other devices in the fume hood should not exceed 50% of the countertop area.
Control the direction of air flow: The design of the fume hood should ensure that the minimum amount of air inside the hood flows back into the laboratory space. The cross-sectional air velocity at the operation opening of the fume hood should not be less than 1m/s. Fume hoods should not be placed near doors or Windows; otherwise, the airflow will short-circuit. If the fume hood is close to the door or window, the door and window should be closed when using the fume hood. Fans and other devices must not be turned on near the fume hood to minimize the interference of ambient air flow as much as possible.
Take good personal protective measures: Laboratory personnel should be equipped with basic personal protective clothing and gear, such as work caps, protective masks, work clothes, work shoes and protective gloves, etc. When handling open-type radioactive substances, one should use the gloves on the glove box to come into contact with the radioactive substances. Gloves are the most vulnerable to contamination by radioactive substances. The general requirements for the performance of gloves are low breathability, softness, toughness, and resistance to acids and alkalis, etc.
Standard operating procedures: Operations such as opening ampoules should be carried out in a fume hood. The operation process should be proficient, quick and errand-free to avoid accidents. During the experiment, operate carefully to avoid radioactive contamination. The radioactive waste generated needs to be collected and stored separately.
Timely cleaning and maintenance: After the fume hood has handled highly toxic, highly residual or radioactive substances, the interior of the fume hood should be immediately cleaned and contaminated. The fume hood should be equipped with water supply, drainage and power supply systems, as well as appropriate lighting. The water supply, drainage and power supply switches should be located outside the fume hood, in places convenient for the staff to operate. For the convenience of cleaning, the countertop is often covered with tiles or other smooth and easy-to-clean materials. And when handling radioactive substances, lay an additional layer of plastic sheet to prevent the countertop from being contaminated in case of contamination.
Set up warning signs: A clear warning sign should be hung on the contaminated fume hood, and the maintenance personnel should be informed of which piping systems may be contaminated to avoid injuring them.
