What Is Medical Grade Oxygen?

Many people may think that inhaling oxygen is easy because it is in the air we breathe. Our ambient air (i.e. the natural air around us) contains only 21% oxygen; the rest is a mixture of nitrogen, argon, carbon dioxide, and other gases. To obtain pure oxygen, oxygen plants must use specialized techniques to separate the oxygen from the air, usually by collecting the air in gaseous form and liquefying it at low temperatures.

Once collected, it must be inspected and packaged into different grades. Next, the oxygen cylinder supplier will introduce things you should know about oxygen cylinders.  

Oxygen Grades: From Aviation to Welding

Industry professionals refer to oxygen grades in a variety of ways. The Compressed Gas Association (CGA) has identified seven grades of oxygen (from A to G) that determine the purity of the oxygen. Oxygen can also be designated as USP, which means it has been certified by the eponymous organization, the United States Pharmacopeia (USP).

Now, almost all oxygen produced in plants meets USP requirements, mainly for economic reasons, by storing it in separate facilities, but it is the purity of the oxygen (i.e., how much other gas is still present) as well as the way the oxygen cylinders are filled with different oxygen grades. There are four recognized "grades" of oxygen used in various industries: welding, research, aviation, and medical.

7L Portable Oxygen Cylinder

Welding oxygen is used in certain types of welding techniques to help generate heat or as an additive to help stabilize the process. When used, other contaminants may enter the oxygen cylinder, such as acetylene, which is used in one type of welding process. When a cylinder must be filled with oxygen, the station operator will test for the presence of acetylene. If it is present, the cylinder is cleaned and then refilled with oxygen. If the cylinder is labeled with medical oxygen, it must be evacuated before filling.

Aviation breathing oxygen (ABO) is strictly regulated and, because of these standards, cannot be substituted for medical or industrial grade oxygen.CGA's E grade is also commonly referred to as pilot grade, and this oxygen must undergo an additional drying step before entering the cylinder.

Research grade oxygen is 99.999% pure ("five nines", also known as Class 5) and is used in chemical research facilities and specialty welding applications in the aerospace industry.

Medical oxygen is used in oxygen therapy and hospitals. It is designated as a drug and therefore must meet FDA requirements for compressed medical gases. One of the requirements is that the cylinder containing the oxygen must always be completely evacuated to minimize the risk of contamination. According to Dr. Larry Taylor of the University of Michigan, the U.S. Food and Drug Administration (FDA) has prosecuted facilities for improperly filling medical-grade oxygen cylinders.

Prescription of medical-grade oxygen.

Because the FDA classifies medical-grade oxygen as a drug, you must have a prescription to purchase that and other medical devices related to oxygen, such as oxygen concentrators. This may seem like an unnecessary step since the production and use of medical oxygen is already controlled, but a prescription is an additional step to ensure that the oxygen you obtain is safe to use.

Common Medical Oxygen Use and Misconceptions

Medical oxygen can be used in a variety of settings. Typically, medical oxygen is used in medical facilities such as hospitals and clinics. It is used for anesthesia, emergency resuscitation, life support for patients who are unable to breathe on their own, and oxygen therapy.

Common Oxygen Misconceptions

A common belief is that we breathe 100% oxygen in the atmosphere. This is not true. The air we breathe is about 21% oxygen and 78% nitrogen. The last 1% is a mixture of carbon dioxide and other gases such as hydrogen.

Another common misconception is that people need high-purity oxygen, and for some occupations or uses, oxygen is close to 100 percent oxygen. For example, high purity oxygen cannot be used for firefighting, deep-sea diving, or other applications. In most cases, conventional air or ABO gas is used, which is usually filtered and cooled for the comfort of the user.

Our friendly customer service team will be happy to answer your oxygen questions and help you choose the right oxygen grade for your needs.