Or to spell it out, can smoking while using an oxygen tank to breathe cause fires or explosions? At my job we’re told to ask people doing this to move to a non-smoking area since it might be dangerous to themselves or others. I think it’s something of an exaggerated danger. Am I wrong?
One data point from my work in drug safety for a pharmaceutical company: I received a report just last month from a clinical trial of serious facial burns from a patient who tried to blow out the candles of his birthday cake while using an oxygen mask…
Incidents like this happen pretty often; a quick google search of “oxygen tank fire” brings up a half dozen news articles on the first page alone (and one YouTube video).
Oxygen accelerates fires; take the oxygen away, and a fire dies. Atmospheric air contains about 21% oxygen, and when you think of a glowing ember/ash from a cigarette/typical fire, that’s the amount of oxygen available to keep that fire going. With a lot more oxygen around though (such as the more or less pure stuff coming out of the tank), the fire will grow significantly, and can spread faster, etc.
There wouldn’t be an explosion if the oxygen is simply directed at and feeding a fire on a couch, for example, but if the tank itself gets too hot, it can explode, and the release of all of that oxygen into a space with an existing flame can cause a rather violent and rapid spread of the fire. Overheating of any compressed gas can cause the tank to explode as the pressure builds, but something like nitrogen (basically inert) would snuff out a nearby fire (if there was enough of it).
Most things laying around go from “you can get it to burn if you try hard enough” to “burns fast and hot like you wouldnt believe” when in the presence of pure oxygen.
Extreme caution around pure O2 is quite reasonable IMO.
Agree with the above comments–O2 is flammable–not explosive. Google “airway fire”. (and keep smoking away from the oxygen!)
oxygen will allow flammable or inflammable things to burn. and it will support rapid combustion of hair, clothes, bedding, body parts and smoking materials.
Video of oxygen flash fire demonstration. Ordinary rag doesn’t burn well by itself, but saturate it with pure O2 (not liquid O2, just gaseous O2), and it burns darn near explosively.
So the collar of your sweater (or your beard, or whatever) happens to have a high concentration of gaseous O2 in it (because you’ve been breathing/exhaling from the mask between drags on your cigarette), and an ember from your cig drops into it. Flames galore.
Note that a pure-O2 environment was the biggest factor in the fatal Apollo 1 launch pad fire.
My dear bride is on oxygen, and she has been warned rather sternly not to cook while on the tank. This is, of course, because we have a gas stove and open flames are a no-no when using oxygen. One interesting bit of info is that they strongly suggest that the mini-tank be worn outside of the clothing because sometimes the gas will buildup in clothes and cause problems.
So, in answer to the OP (and beat to the punch by at least 5 others) I would say "No, not a boom but more like ‘whoosh, aaaaaaaaaaahhhh my eyes!!!’ "
This is iron, just iron, in an oxygen rich environment, heated to it’s burning point.
CMC fnord!
My Mom is on O2 and I thought a demonstration of why you don’t smoke while wearing it was in order. The paper bags burned just like I said they would, but there was some smoldering bag left over. So what would a pyro do? Aim the tubing directly at it of course! :eek: The bag burst into beautiful flames … which jumped to the end of the O2 tubing, which then burned “white (literally) hot”, bright enough to read by, at 3 liters per minute.
If it had been the cannula (in place) instead, instant third degree burns with multiple second degree burns from the [del]napalm[/del] molten plastic.
O2 is not itself flammable - it facilitates the flammability of other things (rather effectively, in many cases). It will make many normally-non-flammable items flammable and many flammable items vigorously or explosively combustible.
Oxygen tanks, and virtually all compressed gas tanks have safety relief valves designed to burst a small metal disc and vent the gas out the back side of the valve to prevent tanks from exploding. I worked for over a dozen years in a transfill facility where these tanks were filled, and a safety would occasionally blow as the tanks were being filled. Quite loud, but quite safe.
Tanks are also pressure tested every 5 or 10 years via hydrostatic testing. I have seen tanks deform after failing, but never saw one explode.
Read the tale of the ValuJet 592 explosion
My grandmother smoked while on oxygen for years.
Almost 30 years ago, when I was a physics undergrad, we used to do demonstrations of low-temp physics during the university’s annual open house/spring festival/student riot. One of these demos included dipping a cigar or cigarette into liquid oxygen (LOX) then lighting it – it would burn up in very short order, giving the demonstrator just enough time for a short quip on the evils of smoking.
LOX, when spilled, also tends to give nastier burns than similar spills of liquid nitrogen, even though LN is colder (77K vs 90K for LOX).
True, but those disks don’t always work. Every now and then somebody in the Scuba industry get scared/injured/killed from an exploding tank.
More importantly, if there is a major fire and an oxygen tank’s safety valve bursts, it dumps out all its oxygen in a short time. That would generally be a very BAD thing. The release of all that oxygen into a fire would probably be nearly explosive in itself.
I’m gonna way oversimplify here but oxygen isn’t an explosive. The air we breathe is like 21% oxygen so we’d all be on fire if it was.
Oxygen is really an enabler of fire. Fire needs three things as you learn in 3rd grade science.
- Heat
- Fuel
- Oxygen
Take away any of those three and it goes out.
In addition nitrogren which accounts for over 70% of the air we breathe actually inhibits fire. I said it inhibits not prevents
Now here’s why it’s dangerous to smoke around oxygen and where I’m gonna oversimply for effect.
Suppose I light a match and accidently drop it on the floor. Chances are it will go out before it hits the carpet. But let’s say it takes 2 seconds to go out. If you are smoking and using oxygen or in an oxygen rich environment, it may now take 10 seconds for the match to go out.
10 seconds is a lot longer than 2 seconds and that is 5 times the chance for that match to catch something on fire.
So you see in this example, oxygen isn’t a combustable but rather an enabler of the fire. It allows the flame to live longer so the possiblity of it catching something else on fire is greater.
Again this is oversimplified but it is the jist of it
Billfish-
you are probably correct wrt SCUBA tanks; I was referring to commercial oxygen tanks like those used in the medical and welding fields. Those frangible discs are very specifically rated and WILL fail well before the tanks is in any danger of exploding. The released oxygen will of course behave as you noted.
Oh, and Markxxx, you have it backwards. The O2 will not allow a flame to last longer; just the opposite. It will burn much more intensely, but for a much briefer time as it will exhaust the fuel much faster.