Is Oxygen an explosive gas

[mshields]

An obvious yes I would have thought. But someone just told me that if you lit a match in a room filled with an excess of oxygen, from say an O2 tank with an open valve, that the match would burn brighter but would not ignite the Oxygen itself.

Is that true?

 

[iwire]

That is my understanding of it.

 

[luckylerado]

https://www.youtube.com/watch?feature=player_embedded&v=a6qGIMqDKwA

SDS sheet from AirGas does not list it as an explosive except to say that increased pressure could cause the container to explode.

http://www.google.com/url?sa=t&rct=...reqbgH&usg=AFQjCNEbCb3Frj0Xx2tRWeuyO1kTk-tSNA

 

[mgookin]

An obvious yes I would have thought. But someone just told me that if you lit a match in a room filled with an excess of oxygen, from say an O2 tank with an open valve, that the match would burn brighter but would not ignite the Oxygen itself.

Is that true?

To have fire you need three things:
Heat, Fuel & Oxygen.

Take away any one of those 3 things and you have no fire.

The O2 gas itself is not flammable or combustible.
Our atmosphere is roughly 79% N2 and 21% O2.
If O2 were combustible none of us would exist.

Yes, your friend's statement is true.

 

[Barbqranch]

But a high concentration of oxygen can make things that are ordinarily only mildly flammable explosive.

Look at a utube video of starting a barbq fire w/ liquid oxygen and briquettes.

 

[kingpb]

O2 is not a combustible gas; nor is it a fuel.

Often times you will see emphysema patients breathing oxygen, and smoking a cigarette and you may erroneously hear someone make a comment such as, "they are going to blow themselves up". The danger is not in the cigarette igniting the oxygen (explosion), it is the high concentration of oxygen that could cause the cigarette (fuel) to burst into flames.

 

[gadfly56]

But a high concentration of oxygen can make things that are ordinarily only mildly flammable explosive.

Look at a utube video of starting a barbq fire w/ liquid oxygen and briquettes.

That is not quite true. You can certainly get a much higher rate of combustion, and some substances such as grease or oil may spontaneously combust under high O2 conditions, but that's not a true high explosive condition. Typically you'll have grease, for example, inside a pipe network. A sudden increase in pressure for pure O2 can lead to local heating (PV = nRT). That heat may be enough to ignite the grease.

 

[Jraef]

Damn, maybe I'm the only one here that learned to weld with an oxyacetylene torch?

Whenever I forgot to turn on the acetylene tank and was spewing pure oxygen out of the tip, nothing I did would make it light up. It NEEDED the "fuel" of the acetylene to make a flame. But if I forgot to turn on the O2, the acetylene burned like a smelly sooty candle that could barely ignite cardboard. Put them together in the right mix however, and I was melting steel.

 

[RichB]

Damn, maybe I'm the only one here that learned to weld with an oxyacetylene torch?

Whenever I forgot to turn on the acetylene tank and was spewing pure oxygen out of the tip, nothing I did would make it light up. It NEEDED the "fuel" of the acetylene to make a flame. But if I forgot to turn on the O2, the acetylene burned like a smelly sooty candle that could barely ignite cardboard. Put them together in the right mix however, and I was melting steel.

and if you wanna get a bang outta life-DO THIS AT YOUR OWN RISK-set it up for a neutral mix, wipe it against your leg so the flame goes out--then hold a striker or Styrofoam cup to it--let it fill with the gas and then light--

I know I know--not the safest thing to do but a small balloon filled like this and then set off is a great waker-upper!! And put into a 10 foot length of 8 inch plastic pipe--wow--2 really big bangs and cool flame

 

[moonshineJ]

An obvious yes I would have thought. But someone just told me that if you lit a match in a room filled with an excess of oxygen, from say an O2 tank with an open valve, that the match would burn brighter but would not ignite the Oxygen itself.

Is that true?

Google "Apollo 1" (pure oxygen at 16.7 psi; 2 psi higher than atmospheric pressure), or "Valentin Bondarenko" (50% O2)

 

[Fulthrotl]

Google "Apollo 1" (pure oxygen at 16.7 psi; 2 psi higher than atmospheric pressure), or "Valentin Bondarenko" (50% O2)

all the welding oxygen gauges i've seen say "use no oil" for a good reason.
anyone who saw the apollo fire on TV, will remember how that turned out.
i don't think it needed to be explosive. it was quite enough as it was.

 

[Tony S]

In the foundry melting plant we used a lot of oxygen to aid the melt in the cupola.

Fortunately I walked past and spotted one of the operators reconnecting an oxygen lance, I stood and watched him as he smeared grease around the flexible hose connection. “It’s a bit stiff”. New flexible hoses and lances were always on free issue in our workshop, he’d gone in to the shop to get grease rather than a new hose and lance?

If anyone can explain how a plant operators mind works, let me know.

 

[mshields]

thank you

thank you

Very interesting - thank you all

 

[K8MHZ]

To have fire you need three things:
Heat, Fuel & Oxygen.

Take away any one of those 3 things and you have no fire.

Perhaps most of the time, but not always.

Florine is also an oxidizer and will support combustion when combined with hydrogen or metals. No oxygen necessary.

There is also no oxygen in the sun, yet there is lots and lots of fire.

 

[GoldDigger]

There is lots of really hot plasma in the sun, but no fire! Nothing interesting there involves any chemical reaction.
Technically fire requires oxidization (with oxygen or some other oxidizer) and flame requires a gaseous fuel. (Glowing charcoal does not involve flame).

 

[K8MHZ]

There is lots of really hot plasma in the sun, but no fire! Nothing interesting there involves any chemical reaction.
Technically fire requires oxidization (with oxygen or some other oxidizer) and flame requires a gaseous fuel. (Glowing charcoal does not involve flame).

Wood is a gaseous fuel? How about solid rocket fuel?

I was looking at a forum thread about chemistry stuff and the debate about the definitions of flame and fire raged on (pun intended) for many pages.

Since I was a kid I always wondered what, exactly, fire was. In simple terms, it is gas that is hot enough to produce light, similar to metal that is red hot and produces light.

 

[GoldDigger]

Wood is a gaseous fuel? How about solid rocket fuel?

What is burning in a wood fire is components of the wood which have been converted to gasses by the heat of the flame.
When the flame is separated from the fuel, that requires that what is burning in the flame itself is in fact a gas.
The non-volatile components of the wood get oxidized too, except for what is left in the form of ash, but they do not form the flame.

I do not know enough about solid rocket fuel to say for sure, but I suspect that it volatilizes too.

 

[qcroanoke]

What is burning in a wood fire is components of the wood which have been converted to gasses by the heat of the flame.
When the flame is separated from the fuel, that requires that what is burning in the flame itself is in fact a gas.
The non-volatile components of the wood get oxidized too, except for what is left in the form of ash, but they do not form the flame.

well, that goes without saying.........

:huh: :lol:

 

[GoldDigger]

well, that goes without saying.........

:huh:

Apparently not, since K8MHZ asked a reasonable question about it.

 

[ggunn]

The short answer is no, oxygen is not an explosive gas but it can make other stuff explosive.