Cryogenic gases or cryogens are gases that are maintained at a temperature of less than -150 degrees Celsius or 123 K. At these temperatures virtually all the gases have liquefied. There are 3 main types of cryogenic liquids. They include inert gases, flammable liquids and oxygen. The inert liquids are those that do not usually react. They include nitrogen, neon, krypton, helium and argon. The highly flammable types burn easily in air. An example is natural gas.
There are numerous uses for cryogens. In medicine, they are used in the field of cryosurgery in the reduction of malignant cells. They help to preserve human tissues for future use. Some reactions generate a lot of heat and the cryogens are used in the cooling process. For instance, the manufacture of drugs such as statins relies heavily on the use of the cryogens.
There are a number of health hazards associated with the use and storage of the cryogens. One of them is that the cryogenist or any other person that handles these products is exposed to very cold temperatures that may cause tissue injury. The resultant damage is similar to that caused by a thermal burn. Delicate mucosal membranes such as the conjunctiva are the most vulnerable. Affected parts of the skin characteristically appear waxy yellow.
The other major risk is asphyxiation. This is caused by displacement of ordinary air from the ground as the cooling cryogens expand. Consequently, the amount of oxygen in the ordinary air is reduced and respiration is compromised. The destruction of the lungs by the cryogens makes the situation worse. The risk for asphyxiation is particularly high in enclosed spaces.
Most of the cryogens are highly flammable especially if allowed to rapidly expand. Highly flammable gases include hydrogen, carbon monoxide and methane. The mixture between hydrogen and ordinary air is in particular very flammable and should be handled carefully. The other cryogen considered to be equally as dangerous in this regard is liquid oxygen. The liquid can cause combustion of materials such as carbon, stainless steel and cast iron.
Because of the associated risks, there are a number of precautions that one should take when handling these substances. For instance, containers must be thermally insulated to prevent ignition. There are a number of flasks available in the market that can be used for transporting the substances. These containers are vacuum-jacketed and non-pressurised. The cap should be loosely fitting to allow for venting of excess pressure but prevent entry of external air and moisture.
It is important that put on personal protective clothing at all times. The clothes must also be maintained clean and dry at all times. They should be well-fitting and cover arms and legs. If the material penetrates your gloves, remove them as soon as possible. For protection of the eyes and the face, googles or a facial shield should be used.
Cryogenic gases are very important and have a wide range of applications both domestically and in an industrial setting. It is important that one learns how to properly handle them to prevent serious accidents. The general advice is that one should always read the instructions and they should consult if unsure about anything.
There are numerous uses for cryogens. In medicine, they are used in the field of cryosurgery in the reduction of malignant cells. They help to preserve human tissues for future use. Some reactions generate a lot of heat and the cryogens are used in the cooling process. For instance, the manufacture of drugs such as statins relies heavily on the use of the cryogens.
There are a number of health hazards associated with the use and storage of the cryogens. One of them is that the cryogenist or any other person that handles these products is exposed to very cold temperatures that may cause tissue injury. The resultant damage is similar to that caused by a thermal burn. Delicate mucosal membranes such as the conjunctiva are the most vulnerable. Affected parts of the skin characteristically appear waxy yellow.
The other major risk is asphyxiation. This is caused by displacement of ordinary air from the ground as the cooling cryogens expand. Consequently, the amount of oxygen in the ordinary air is reduced and respiration is compromised. The destruction of the lungs by the cryogens makes the situation worse. The risk for asphyxiation is particularly high in enclosed spaces.
Most of the cryogens are highly flammable especially if allowed to rapidly expand. Highly flammable gases include hydrogen, carbon monoxide and methane. The mixture between hydrogen and ordinary air is in particular very flammable and should be handled carefully. The other cryogen considered to be equally as dangerous in this regard is liquid oxygen. The liquid can cause combustion of materials such as carbon, stainless steel and cast iron.
Because of the associated risks, there are a number of precautions that one should take when handling these substances. For instance, containers must be thermally insulated to prevent ignition. There are a number of flasks available in the market that can be used for transporting the substances. These containers are vacuum-jacketed and non-pressurised. The cap should be loosely fitting to allow for venting of excess pressure but prevent entry of external air and moisture.
It is important that put on personal protective clothing at all times. The clothes must also be maintained clean and dry at all times. They should be well-fitting and cover arms and legs. If the material penetrates your gloves, remove them as soon as possible. For protection of the eyes and the face, googles or a facial shield should be used.
Cryogenic gases are very important and have a wide range of applications both domestically and in an industrial setting. It is important that one learns how to properly handle them to prevent serious accidents. The general advice is that one should always read the instructions and they should consult if unsure about anything.
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