Handling Cryogenic Gases Safely

Cryogenic liquids are gases at normal temperatures and pressures. Cryogenic means “producing, or related to, low temperatures” and all cryogens are particularly cold. If cryogenic liquids are at low temperatures they are in their initial liquid state.  However, cryogenic liquids have boiling points below -150 degrees Celsius. For cryogenic gases to liquefy they must be cooled below room temperature before an increase in pressure can make the change back from a gas to a liquid.  Cryogenic liquids condense the moisture in the air creating fog that is very visible to the human eye. Every cryogen differs when becoming a liquid.

There are three main groups that cryogenic liquids can be placed into they included, inert gases, flammable gases and lastly oxygen. A few examples of inert gases are helium, nitrogen and argon. Inert gases do not react chemically to any large extent. The next group is flammable gases. Flammable gases are when some cryogens produce a gas that can burn in the air

The last group that cryogenic liquids can be placed into is oxygen. Various materials that are considered as non-combustible can burn in the presence of liquid oxygen.

It is crucial that individuals who are working with cryogenic gases know how to properly handle these chemicals in a safe manner. The first thing that is essential when handling cryogenic gases is to wear the appropriate personal protective equipment. The PPE that is to be worn is safety shoes along with fully covered arms and legs, full face shield and safety goggles, a lab coat and insulated or leather gloves.

When handling cryogenic liquids do not let any unprotected part of your body come in contact with non-insulated pipe that contain cryogens. If individuals come in contact it can cause serious damage to their tissue; the symptoms are very similar to those of thermal burns or frostbite.  This is because the pipes are very cold metal and if someone was to come in contact with out their personal protective clothing it could cause their skin to stick to the metal and tear when attempting to get it off. Another safety consideration when handling cryogenic gases, is that the substances become delicate and may shatter when cold. Knowing this when handling cryogens will help individuals be more cautious of what they are doing knowing the risks that it cause if the substances were to shatter.

 Individuals handling cryogenic liquids should only be working with them if they are extremely aware and knowledgeable on the properties of the materials and the equipment being used. When handling these gases there should be written procedures within the lab that have been developed giving specific detailed instructions on the multiple cryogens being used within the lab.

Cryogenic gases can cause many safety hazards, so knowing how to store them properly is an important aspect in keeping individuals working with cryogenic gases safe. According to the Canadian Centre for Occupational Health and Safety “inspect all incoming containers before storing to ensure they are not damaged and are properly labelled.” When storing cryogenic containers it is important to note not to store the containers where they may come into contact with moisture, they are to be stored upright in well ventilated areas. Some of the hazards include, extreme cold, asphyxiation, toxic hazards, fire hazards, oxygen enriched air hazard embrittlement and liquid oxygen hazard. When working with cryogens always handle with caution in order to keep you and those around you safe. 

 https://www.ccohs.ca/oshanswers/chemicals/cryogenic/cryogen1.html

 http://www.hsc.wvu.edu/safety/Laboratory-Safety/Cryogenic-Liquids.aspx

 https://www.ccohs.ca/oshanswers/prevention/cryogens.html