Pure 100% Oxygen is bad to breathe?

Question

My teacher was like breathing in 100% oxygen is bad, how is that bad I mean?? Isn't that the only thing we inhale and use. I just don't get it.
Well I suppose too much of a good thing is a bad things

Answer 1

Lavender gave you the key information you need, i.e., too much oxygen damages the body. Probably the best-known example of this is blindness in prematurely born infants due to breathing pure oxygen for extended periods (which is sometimes necessary to keep them alive). There are probably medical techniques available today to minimize this problem, but it has been a serious issue in past years (20 years ago in one example I am familiar with).

Here is a bit more information about breathing pure oxygen, and some clarification of the comments from others.

You can breathe pure oxygen for short periods in order to recover from lack of oxygen (athletes do it, as do firemen who have inhaled smoke, for example).

The air we breathe at sea level is at a pressure of 14.7 psi, and 21% of it is oxygen. (78% is nitrogen, and most of the other 1% is argon.) If you take 21% of 14.7psi, you'll see that we are breathing oxygen at a pressure of about 3 psi.

Pilots and astronauts can breathe pure oxygen, but as Lavender points out, they breathe oxygen at a pressure lower than sea level air pressure. If their oxygen is delivered to them at 3 psi, then it is equivalent to the oxygen in our air at sea level. (And incidentally, the air we breathe is not much changed at elevations up to 5,000 or 10,000 feet. As a rule of thumb, you can notice the difference in air pressure (the difference in the availability of oxygen) when you get close to 10,000 feet of elevation. At 18,000 feet, the air pressure is about 50% of that at sea level. And after another 18,000 feet, the pressure at 36,000 feet is cut in half again, so it is about 25% of the sea level pressure.)

Answer 2

100% oxygen is indeed a variety of gas that is much different than the air that we breathe as many have mentioned already. However, the primary reason why 100% oxygen is detrimental to the body is because of its tendency to form free radicals. Upon inhalation of 100% oxygen, superoxide ions (O2-) and hydrogen peroxide are formed within the body. Both of these compounds are extremely hazardous as they readily react with biological molecules such as enzymes and proteins. So, in effect, breathing in 100% oxygen essentially damages proteins and enzymes that are critical to life.

As actuator pointed out, some infants are given this type of oxygen treatment (hyperbaric oxygen) to help them breathe, but I'm pretty sure this is an outdated method since it does cause blindness in the infant. The free radicals attack the retinal cells in the eye and render them incapacitated.

Answer 3

Our atmosphere contains roughly 78% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, trace amounts of other gases, and a variable amount (average around 1%) of water vapor. Oxygen is highly toxic to animal life - breathing pure oxygen for more than a short time can cause damage to the lungs. And if 100% oxygen is breathed in a high-pressure environment this can cause oxygen toxicity in the body, leading to seizures and eventual death.

Answer 4

In medical applications (such as in ventilation gas mixtures in hospital applications) mixtures containing more than 50% oxygen will cause lung toxicity, damaging lungs over periods of days, with the rate of damage rising rapidly from mixtures between 50% and 100% oxygen.
But you can breath 100% oxygen without any damage if u are in space.
It is becoz of the difference of pressure.

Answer 5

I believe 100% oxygen is bad for us. I know we only breath in a percentage of oxygen, I'm not sure of the percentage.

Answer 6

the air we breathe is only 21% oxygen. It's over 70% nitrogen, and 1% or less of a handful of other elements.

Answer 7

X + O2 --> Combustion reaction

So basically any high concentration of oxygen will results in rapid combustion making it impossible to breathe without going up in flames.

Answer 8

im not sure the exact amount of oxygen we breathe in but i cant tell u this it is not pure oxygen i believe it is composed of nitrogen as well

Answer 9

oxygen forms O3 partially, which is deadly at high quantities (such as what would be in 100% oxygen)

Answer 10

Oxygen kills.