Liquid oxygen is the liquid form of the gaseous oxygen necessary for human life. It has many uses, but there are also definite dangers involved in working with liquid oxygen.
Liquid oxygen was first created under laboratory conditions in on April 5, 1883. This was achieved by a compressor created by Polish chemists Karol Olszewski and Zygmunt Wróblewski at Jagiellonian University in Cracov.
To produce liquid oxygen, air is compressed and cooled to -196 degrees Celsius. The gases in the air are liquid at this point before the room is heated -183, reverting the nitrogen in the air to gas and leaving only liquid oxygen behind.
Liquid oxygen is pale blue in color and extremely cold. It is stored under pressure in specially designed metal containers.
Liquid oxygen is used in cryogenics. It is also used in the production of rocket fuel and can be used to make explosives.
Liquid oxygen is non-toxic, but its extremely low temperatures can cause severe burns rather quickly and can also make structural items brittle and dangerously unstable. Liquid oxygen is also highly flammable.