Factoids

Oxygen is fundamental to the life of all living organisms, using oxygen as the principal terminal electron acceptor at the end of the electron transport chain. It is from this transfer of electrons that such organisms generate energy from food. All such organisms, including us, are referred to as "aerobic."

Not surprisingly, the most abundant form of life sustained by oxygen are the microorganisms. More surprisingly perhaps, is that a high proportion of these microorganisms are limited in their growth by the limited availability of oxygen. Today, the biotechnology industry relies heavily on optimizing microbial growth by supplying enough oxygen to selected microorganisms to allow them to grow and create chemicals and materials for uses as diverse as food, disease control and cosmetics.

Oxygen is the activator of some of the most active biological molecules known. Some of these molecules, e.g. peroxidase enzymes, are now being used as "magic bullets" to destroy harmful man-made chemicals which are otherwise difficult to destroy by other means.

Although oxygen is one of the keys to life, it is a deadly toxin to some microorganisms, and at high concentrations it can even be damaging to some living cells that require oxygen to survive.

Oxygen is very important for all living creatures. This fact makes oxygen as dangerous as it makes it important. Two major dangers are the "too low" and the "exceed" of oxygen content in the air. The normal amount should be 21%.

About too low an amount of oxygen in the air (<21%):

You can survive—: 3 weeks without food; 3 days without water/drinking; 3 minutes without air; Only 2 breaths of air without oxygen

When the oxygen content in the air is 0%, human beings will lose consciousness at the second breath, without warning signals (pain, dizziness, etc.). If you survive, the risk of brain damage is high.

About an excess of oxygen in the air (>21%):

An excess of oxygen in air is very dangerous regarding the increase of the combustibility of materials. More than 21% of oxygen helps materials to burn (oxidize) better and faster and, coupled with the fact that the gas has neither odor nor color, makes an excess of oxygen in air very dangerous. An increase of just 3% from the ambient oxygen concentration of 21% doubles the combustion velocity. By the time this figure reaches 40%, the combustion velocity in contact with a spark or naked flame increases tenfold. Since in the manufacturing (metal) industry oxygen is a commonly used gas, the risk of excess oxygen in the workshop is always fairly high.

Different precautions can be taken to minimize the risks of oxygen, such as:

provide adequate ventilation
use oxygen level meters
use two operators connected with lifeline when entering confined space where there is a risk of too little oxygen or enrichment
make sure all couplings of hoses are gas-tight; use leak testing spray
set correct pressures on control equipment and use the right nozzles
wear appropriate clothing
during prolonged breaks, remove hoses from confined space
never use oxygen for uses other than those for which the gas is intended:
- never blow working clothes clean with oxygen
- never use oxygen for pneumatic tools or spray-painting equipment
- never use oxygen for blowing pipe systems clean
- never use oxygen for ventilation or cooling
always ensure that regulators and connections from oxygen service are completely free from oil and grease, because oil and grease in contact with oxygen, especially at high pressures, can ignite explosively
If handled carefully, the risks of oxygen are minimal

Due to slightly unbalanced electron spin in its atoms, oxygen is susceptible to magnetism. In this respect, oxygen is a paramagnetic gas. Liquid oxygen is strongly paramagnetic—it can be lifted by strong magnets.

Combustion is a chemical reaction between fuel and oxygen that leads to the generation of heat. Air contains 20.9% oxygen, the rest being mostly nitrogen and a small amount of argon. When the oxygen concentration is raised above the normal 20.9%, the air is said to be oxygen-enriched.

As air contains only 21% oxygen by volume, at any given temperature and pressure, it is possible to dissolve in water almost 5 times the quantity of oxygen from pure oxygen as from the atmosphere. This is in accordance with Henry's Law.

Air contains 78% nitrogen. In using air to oxygenate liquids, this nitrogen is wasted and returns to atmosphere. In doing this it unfortunately takes some oxygen with it, and also vapors from the liquid. This is why pure oxygen is often used to add oxygen to biological and chemical processes at industrial scale. Industrially produced oxygen can actually reduce air pollution caused by air itself!

Interesting to note that the composition of the air is 21% O₂ is at the level where dry wood burns well but damp vegetation will not easily burn. If O₂ were at just a few percent higher wet vegetation would burn and forests would not be sustainable. For the same reason O₂ is commercially important because it can enhance combustion of carbonaceous fuels even with a few percent enrichment.

LOI or Limited Oxygen Index, is an index used for defining the combustion resistance of materials.

Liquid O₂ is quite heavy. While the O₂ we breathe is "light as air," liquid O₂ is heavier than water—9.5 lbs/gal vs. 8.3 lbs/gal for water.

On the lighter side of things, how about 'Marine Boy' who could stay underwater for great lengths of time through chewing 'oxygum'. This was a very popular cartoon series in the late sixties and early seventies, certainly in the UK, Australia and Japan. See http://www.alphalink.com.au/~roglen/marine.htm for more info.

At 8:02 p.m. on February 20 this year there will be an historic moment in time.

It will not be marked by the chiming of any clocks or the ringing of bells, but at that precise time, on that specific date, something will happen which has not occurred for 1,001 years and will never happen again.

As the clock ticks over from 8:01 p.m. on Wednesday, February 20, time will, for sixty seconds only, read in perfect symmetry 2002, 2002, 2002, or to be more precise, 20:02, 20/02, 2002.

This historic event will never have the same poignancy as the 11th hour of the 11th day of the 11th month which marks Armistice Day, but it is an event which has only ever happened once before, and is something which will never be repeated.

The last occasion that time read in such a symmetrical pattern was long before the days of the digital watch and the 24-hour clock—at 10:01 a.m. on January 10, 1001.

And because the clock only goes up to 23:59, it is something that will never happen again.