7 Important Rules For Safe Work With Cryogenic Liquids

by Cryonos Project on October 18, 2021

7 Important Rules For Safe Work With Cryogenic Liquids

Handling materials that may freeze you, or suffocate you, or blow you away is not an easy job. Strict rules need to be in place and these need to be followed closely. Cryogenic liquids can give many benefits if handled with caution.

Here are the 7 rules that will bring the benefits and keep the hazards at a distance:

1.     Substitution

The first safety method is avoiding hazardous cryogenic substances altogether. Do some research for what options you may have for your discrete task, and substitute more hazardous cryogenic substances with less such.

2.     Ensure Good Ventilation

Proper ventilation where cryogenic liquids are stored reduces the risks of fire, asphyxiation, and explosion. The word “proper” means that the ventilation needs to be compliant with the room, the type of job, the number of materials. Special care should be taken to ensure hazard-free ventilation and it is highly recommendable to have an individual ventilation system only for cryogenic liquids.

3.     Proper Storage

Start with ensuring that the incoming containers are not broken or damaged. Ensure proper labeling. Never accept defective or poorly labeled containers in your storage.

Cover dewar flasks with a loose cover. This will not allow moisture to enter but will help pressure escape. Refrain from using glass dewar flasks for storage of combustible or oxidizing cryogenic liquids. When using glass dewar flasks, cover them with tape. This will reduce hazards with broken glass, should the flask be broken when coming into contact with the cryogenic fluid.

Monitor for the formation of ice around the caps of the flasks. Helium and hydrogen may freeze the water from the surrounding air. If this should happen a pressure-related hazard is possible. If this should occur, use the manufacturer’s manual for dealing with such issues. Ice may also cause the malfunction of pressure valves. Monitor for such ice build-up and ensure timely removal.   

Take care to avoid storing liquid oxygen near combustible or other flammable materials. Store flasks away from moving or heating sources.

Ensure careful handling of containers and restrict access to them for only authorized personal. 

4.     Transportation

Never move containers by rolling them on their lower rim. Always use a proper lifting device. Also do not pull containers. Rather push them, which will reduce the risk of a container accidentally falling and injuring someone. Secure containers during transport using straps and always keep them upright. When using elevators, transport cryogenic liquids without passengers in the elevator.

5.     Using Liquids

Cryogen liquids should only be handled by persons who are aware of their properties and possible hazards. Carefully select the materials to use with cryogen liquids, as many common materials such as plastic, rubber, and steel become brittle at cryogenic temperatures.

When submersing materials in cryogen liquids, do so slowly to avoid any unwanted splashes. Always use tongs. Also do not wear any watches, jewelry, or such, as they may freeze if in contact with the liquids on exposed skin.

6.     Transferring Liquids

When transferring to a new dewar flask, take care that the receiving container is already cool. Then fill slowly, so that the cryogen liquid may further cool the new flask. Always use the proper filling device and the correct containers for the specific cryogen liquid.

7.     Personal Protection

 Always be sure to wear proper protection as per the procedure and be cautious that the liquids do not make skin contact. Wear a non-porous laboratory coat with long sleeves, as cryogen liquids pass through the porous material.

Always wear glasses, and a full-face shield or mask to protect your face also, take care not to breathe harmful gasses. The task may require that you use a respirator.

If contact does occur, immediately rinse the place with warm water.

Now you know the basic rules of safely handling cryogenic liquids.

Work with care.

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