The main dangers are frostbite and suffocation.

· Frostbite prevention: Be sure to wear antifreeze gloves and goggles to avoid direct contact with low-temperature liquids or metal surfaces.

· Suffocation prevention: Make sure to operate in a well-ventilated area, because the evaporated nitrogen will replace oxygen, and there is a risk of hypoxia in a closed space.

It is necessary to distinguish the situation:

· Slight frosting/lower end frosting: For newly filled Dewar bottles or when the ambient humidity is high, it is normal to have slight frosting near the neck tube or at the bottom of the bottle.

· Severe frosting in a large area: If there is thick and uniform frosting in the whole bottle, especially the upper half, this is usually a sign of vacuum failure, indicating that the insulation performance has seriously decreased. Use should be stopped immediately and the supplier should be contacted.

· Keep clean: Clean the outer wall regularly to prevent dust from blocking the exhaust pores.

· Check the vacuum: touch the bottle regularly to confirm that there is no abnormal large-area frosting.

· Cover the bottle cap: Even if the bottle is empty, the bottle cap should be closed to prevent impurities and moisture from entering, resulting in freezing inside.

· Anti-corrosion: Avoid storing in a corrosive chemical environment.

· Short distance: Use a special trolley and make sure that the Dewar bottle is fixed in the car.

· When moving: Be sure to keep the Dewar bottle upright, and it is strictly forbidden to dump, roll or put it horizontally.

· Going up and down the stairs: It must be operated by two people, using a special carrying rack or trolley, and never carrying it alone.