Ask A Scientist© Molecular Biology Archive

name         Serggie T.
status       student
age          20s

Question -   How is oxygen converted to liquid? Is it possible to
take this orally without harmful side effects?

I saw something in the Internet that mentioned the benefits of stabilized
liquid oxygen to health. According to this site, liquid oxygen has proven to be 
effective in treating genital herpes and certain cancers. Is this true?

Liquid oxygen is obtained from the distillation of liquid air, which is
about 80% nitrogen, 19% oxygen, and small amounts of the inert gases:
Ar, Kr, Xe. Liquid air is obtained by the rapid expansion of high pressure
gaseous air which has been purified to remove CO2, and other high boiling
substances, e.g. hydrocarbons, that might plug the expansion orifice. The
liquefaction occurs because of the Joule-Thomson effect. You can find this
discussed in detail in any physical chemistry or thermodynamics text.

Liquid oxygen boils at -183 C., so ingestion would produce severe cryogenic
burns, which I put in the category of seriously harmful side effects.

I got my Ph.D. in an area involving cryogenics, and I have never heard of
any such thing as "stabilized liquid oxygen".

Liquid oxygen is a powerful oxidizing agent. It reacts explosively with any
organic substance, and even metals. For example, steel wool. I do not believe
it would be used in any medical application involving direct contact with
tissue.

Liquid nitrogen, which boils at -196 C. on the other hand is chemically
inert and is very commonly used by physicians to remove warts and other skin
lesions.

Vince Calder
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