Cryogenic liquids are gases that can be liquefied by lowering their temperature. These then, at a certain boiling temperature, which can vary from -73°C to -269°C, pass from the gaseous to the liquid state.
The most common cryogenic gases fall into the category of atmospheric gases and are, for example, nitrogen, oxygen and carbon dioxide, which are used in many different types of industries and are transported, handled and stored in the liquid state, i.e. at cryogenic temperatures.
The high speed with which these gases can pass from the liquid to the gaseous state necessarily implies that important safety precautions and operations must be observed.
In the case of brief contact with a cryogenic liquid, the risk is limited due to the formation of a gas film between the fluid and the skin. Prolonged contact, on the other hand, is very dangerous, as is impregnation of clothing and hair.
At first, the cold burn may not be painful and it can be observed that the frozen skin has a waxy, yellowish appearance. After thawing, however, the tissue swells and blisters may appear on the affected area.
In the case of a cold burn, one should proceed in the same way as for burns: rinse with barely lukewarm water and, after thawing, cover with sterile gauze. It is essential:
- DO NOT use hot air jets to ‘defrost’ the affected area
- DO NOT rub the wound
- DO NOT apply ointments or salves
- In the most serious cases, seek medical attention as soon as possible
As for liquid nitrogen, its temperature is very low: -196°C, and its danger should not be underestimated. In the event of accidental contact with the skin, it can cause severe cold burns and, in extreme cases, freezing of the affected part. Clearly, in this case, there is a risk of deep injuries and even total impairment of the affected body part.
Take proper precautions to avoid serious harm to workers
To protect the health of operators and minimise risks, the use of cryogenic liquids requires the adoption of certain behavioural rules:
- always wear suitable safety equipment
- follow the instructions in the safety data sheets
- only use containers specifically certified for the intended use
- avoid proximity to vapours from the containers used
- move away from the operating area in the event of vapour leaks
- only enter rooms where cryogenic liquids are used if authorised and properly protected
What PPE allows the handling of cryogenic liquids
Special attention must therefore be paid to all operations involving the direct use of liquid cryogenic elements. In fact, the most frequent risks occur in decanting operations and in the immersion and extraction of objects from the liquid; this is because these procedures often cause splashing due to the variation in the temperature of the cryogenic liquid.
To try to limit the occurrence of risks or serious harm to the operator, these operations must always be carried out slowly, with the use of appropriate Personal Protective Equipment (PPE) such as:
- Cold-resistant gloves conforming to EN 511 and tested for use in cryogenic environments.
- Clothing for body protection, such as overalls, gowns or aprons made of liquid-repellent materials
- Goggles or visors fitted with side protectors or visors (EN 166)
- Gaiters or foot protection boots tested for cryogenic use.
- In special cases, the use of a cap or helmet for head protection is also recommended.
It is also recommended to use pliers or tongs to extract objects immersed in the liquid, handling both these and the objects with care.
Additional risks not to be underestimated
We also mention other issues that should not be underestimated in the handling of cryogenic liquid containers and all related activities:
Lung damage
As a result of inhaling vapours at low temperatures, lung function may be impaired to a greater or lesser extent.
Gases are not toxic, however they can take away oxygen in small or unventilated rooms.
In these cases, suffocation sometimes occurs without premonitory symptoms, leading to fainting and death of the workers present.
This is why it is essential to follow basic guidelines such as:
- AVOID being in closed, unventilated rooms where pouring is in progress or where large quantities of cryogenic fluids are stored.
- DO NOT enter tanks or descend into pits without prior ventilation.
- DO NOT rescue unconscious persons without adequate self-contained breathing apparatus.
- Ventilate the room immediately.
Explosion
This is one of the most significant risks associated with cryogenics and is mainly due to an increase in the internal pressure of a vessel.
This is why it is important to comply with the procedures and regulations concerning the use of the equipment and the various installations.
It is recommended that a vessel or pipe containing cryogenic liquids should never be hermetically sealed to avoid the risk of explosion, and safety valves should always be installed in conjunction with this.
Our PPE for cold protection
Among Coval Safety’s product categories, the COLD line specialises in gloves and accessories against low temperatures and cold ‘burns’.
All PPE is manufactured from highly insulating technical materials and is a necessary solution to counter extreme cold, both during industrial activities and in extreme climatic conditions.
Cryogenic gloves are ideal for preventing contact cold and burns in the event of liquid gas spills or splashes, in heavy industry or laboratories, being tested according to EN 511 and by contact with liquid nitrogen (-196°C) for one minute and subsequent flexibility test.
All clothing accessories, such as aprons and gaiters, are made of materials that are resistant to liquid gas splashes, and therefore provide a much-needed special protective barrier.
Recommended uses:
cryogenic installations and laboratories: biology, medical technology, scientific research
transport, loading, storage, transfer of liquid gases
They comply with the standards:
EN 388:2016+A1:2018 protective gloves against mechanical risks
EN 511:2006 cold protection gloves
Against skin exposure to very low temperatures, which can cause burn-like damage, we offer specific PPE, such as H.CRYO cryogenic gaiters.
✅Tested for liquid nitrogen -196°C
✅For cryogenic laboratories
For body protection, the L.CRYO cryogenic apron is the ideal safety device when working in contact with low temperatures.
Among the options for hand protection are the CRYOKIT 400 cryogenic gloves. Ideal for laboratory use, they are tested for use with liquid nitrogen as they prevent burns caused by liquid gas splashes. Their length is designed to also act as a barrier to forearms against the risk of sudden splashes.
Finally, for those seeking complete personal protection in cryogenic environments, we suggest the CRYOKIT CASE. A handy case, useful for keeping PPE clean and safe, protecting it from dust and light.
Inside are the devices you need to make the most of your working day:
✅a pair of cryogenic gloves of your choice
✅one L.CRYO apron
✅ one half-bonnet with CLEAR CRYO visor
✅one pair of H.CRYO gaiters
The importance of knowing the regulations and following procedures
As with all tasks that entail great risks for workers, whether they are related to the land, mechanical or cryogenic sectors, what is fundamental is the awareness that the correct training of personnel and the company’s investment in certified and controlled PPE are essential factors for the safety of all operators.
Ensuring that your employees can work in a safe and constantly monitored environment leads to the cornerstones of our Vision:
A more protected worker.
A job done at its best.
A richer and more respected company.
A happier family.