Some Characteristics Of Cryogenic Gases

By Grace Rivas

Cryogenic gases (cryogens) refer to gases that have been called to a temperature of less than 123K or -150 degrees Celsius. Usually at these temperatures, the gases cool down and liquefy. The cryogens are generally divided into three. They include inert gases, flammable liquids and oxygen. The inert liquids are unreactive with other substances. They include neon, nitrogen, argon, krypton and helium. Highly flammable liquids are those that burn very easily in air.

There are many uses for the cryogens. In the medical field, they are commonly in cryosurgery. Here, they help in treatment of cancer by destroying some of the malignant cells. They are also used in the preservation of both animal and human tissues for future use. Some reactions are associated with production of heat and the cryogens help in the maintenance of a lower temperature.

The use of cryogens is associated with several health risks. For instance, directly exposure to the cryogens may result in tissue injuries due to the very low temperatures. These injuries resemble those that are caused by thermal burns. The eyes and mucosal surfaces of the body are at a particularly high risk. The affected skin takes a waxy yellow appearance.

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 one puts on protective clothing. The clothing should be made out of natural fibres and must be well-fitting. It should cover the hands as well as the feet. If the substance penetrates the clothing, the clothing should be removed immediately and through washing done. A face mask or goggles may help protect the face.

Cryogenic gases have a wide range of applications. They are, however, very dangerous if not properly handled. Understanding the precautions required is very important. Ensure that you always read the instructions on how to use them. If anything is unclear, make sure that you consult.

About the Author:

No comments:

Post a Comment