Handling Cryogens Safely
The hazards associated with the handling of cryogenic fluids include cold contact burns and freezing. This happens when skin comes in contact with cold liquid, gas or surface.
The potential for freezing by contact with the extreme cold of cryogens necessitates varying degrees of eye, hand and body protection.
When a cryogenic fluid is spilled on a person, a thin gaseous layer apparently forms next to the skin. This layer protects tissue from freezing, provided the contact with the cryogen involves small quantities of liquid and brief exposures to dry skin. However, having moist skin, exposure to moving cryogens, or extended periods of time, can freeze tissue.
The most likely cause of frostbite to the hands and body is contact with cold metal surfaces. Since there is no protective layer of gas formed, frostbite will occur almost instantaneously, especially when the skin is moist. The damage from this freezing (frostbite)occurs as the tissue thaws. Intense hypothermia (abnormal accumulation of blood) usually takes place.
Additionally, a blood clot may form along with the accumulation of body fluids, which decreases the local circulation of blood.
Adequate protection and clothing is required at all times when handling, transferring or operating near cryogenic fluids. Should a burn occur, immerse the injured tissue in tepid water but do not rub or scratch the area.
Wear Personal Protective Clothing
Whenever handling or transferring cryogenic fluids from one vessel to another, protective clothing should be worn.
• face shield or safety goggles (not safety glasses)
• Loose-fitting, insulating Cryo-gloves (inspect for holes before using)
• Long pants
• Long-sleeved over-shirt, lab coat or apron
• Closed-toe shoes (no sandals or crocks
• Ear muffs or ear plugs
A special note on insulated gloves:
Gloves should be loose-fitting so they are able
to be quickly removed if cryogenic liquid is spilled on them. Insulated gloves are not made to permit the hands to be put into a cryogenic liquid.
They will only provide short-term protection from accidental contact with the liquid.