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Using a C02 fire extinguisher on stage


jessicathanki

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Hi All

 

Has anyone used a fire extinguisher on stage as part of a show? In the final scene of the show I'm working on a character attempts to put out a fire with a fire extinguisher. The director would quite like to use an actual fire extinguisher. Is this possible? if so I know it's quite expensive to recharge/fill the extinguisher (we're touring for 8 weeks) can it be filled with something else? Or does anyone have an alternative ideas?

 

Thanks in advance.

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Not a real fire surely?! Might need a bit/lot more info here.

 

Before you worry about getting a fire out you would be better to see if the various venues will let you have a fire onstage anyway. You might be aware that there are all sorts of devices to detect fire/smoke on a stage and these may have to be momentarily de-activated for the effect. It may be that this sort of thing is a no no anyway...local regs, insurers and so on.

 

(Quick aside; you may or may not know that some theatres won't even allow smoke or haze or pyros so the chances of having a real blaze onstage may be somewhat slim.)

 

IF you are planning a real fire onstage then your RA would say that you would need a whole host of precautions not least of which a fire extinguisher(s), and possibly fire marshals etc, etc, would have to be on hand.

 

How else would you get the fire extinguished once the curtain comes down?

 

You mentioned that the character attempts to extinguish the fire...does that imply the curtain goes down with the fire still alight? I suspect you could not get away with a few token puffs of co2 for effect as the fire has to be extinguished anyway.

 

You would, in all probability, have to use the fire bottle to do that and it would not be a terribly clever idea to use yours sparingly and then empty the bottles belonging to the theatre.

 

If this fire is a prop, in that it is built along the lines of a fan and silk flames and gelled lantern, say, then that is a completely different matter. Blasting it with co2 is therefore simply using another prop as it were.

 

Your query about filling the the bottles with "something else" is tricky in that any compressed gas will cost and it might be compressed co2 is the cheapest anyway.

 

Without wishing to dampen your enthusiasm, if the fire was real then you could not, ever, use compressed oxygen or air for obvious reasons...

 

Cost is what it is. Looks like you will be spending a bit of time with google...there are several outlets for co2 fire bottles, so suggest you present the Director with a list of options ref the cost for the entire run.

 

Might be that the prop fire (as above) and a few token puffs gets his vote after all.

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I would be concerned with filling a fire extinguisher with any other than it was meant to be filled with.

If there was a real fire and someone grabbed the "doctored" extinguisher that had been filled with something else then it wouldn't be much use for it's intended purpose.

Cheers

Gerry

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Assuming that you're not actually trying to put out a real fire...

 

CO2 can't be seen coming out of a fire extinguisher, the biggest thing you notice is the noise. It may be possible to fit a small compression driver in the horn of a prop extinguisher with a battery powered amp & sample playback device in the main cylinder.

 

Maybe get the actor on a fire safety course, so they can use a real one and get a feel for the weight and forces exerted to help them move the prop in the right way as it goes off.

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Co2 would give you a visable fog and the sound you are after - don't think there is any real problem using one on a fake fire - if you just have a couple of blasts per show, it will last about a week per tank. There are refurbish and refill comapanies in most cities, I am sure they would rent you extingushers, possibly even ones that would need degassed for refurb anyway - kept in a prop box so no one tries to use it as a firefighting tool - game on - you can weigh and track how much each show needs.

 

A refillable foam unit with a schroder valve (car tyre) could be modified to spit some talc from the hose with the air pressure in it - and refilled each night with talc and charged on a compressor.

 

CO2 for my money

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CO2 can't be seen coming out of a fire extinguisher, the biggest thing you notice is the noise.

Er, what??

Of course you see the output from a CO2 extinguisher! Gives you the same gasseous effect as dry ice, just shorter lasting, faster output and LOUDER!

 

I spoke with our regular extinguisher service guy a few years ago and he brought us a job lot of expired units to use in the destuction sceene in panto. After 10 yrs I believe they have to be taken out of circulation. He brought us enough to cover a 2 week show, with 'steam' jets coming from about 4 or 5 points around the stage.

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Hey all

 

Thanks for the replies!!! Definitely no real fire on stage!!!! But the director wants the sound and fog from the fire extinguisher. It's only going to be one squirt, maximum 2. It's good to know that one extinguisher will last about a week. I thought that after one use it lost pressure. Now on the hunt for a cheap batch of extinguishers...

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** laughs out loud **, well Jess', it all depends on how big the bottle is and how long the burst(s).

 

Might be a notion to start off in a conservative manner and become more profligate/reckless as you get to know how the bottle "works". (I could see the last perf in the run lasting a little longer whilst the actor extracts the full value for money out of the bottle.)

 

Yes it will be loud so you might want to ask the sound guys to drop the levels a bit if on rms or atmos mics say.

 

Harking back to RAs, you might want to search for the insulated nozzle types and make sure the actor reads the instructions before use and not while waiting for their hands to thaw...

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A CO2 extinguisher doesn't last as long as you might think (ISTR 6 seconds?). I'd get in touch with a local (rather than national) service company and see if they would lend/hire a few for the run. Gives you some slack in the re-filling cycle. There should be a company anywhere you travel that could refill for you.

 

Include in the RA that the horn gets VERY cold. Freeze burns are a reality.

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Thanks Paul, note that it was outdoors in a stiff breeze. Using CO2 extinguishers in a confined space with poor ventilation around humans has other problems besides freeze burns.

 

"The amount of carbon dioxide needed to reduce the oxygen level to a point at which various fuels are prevented from burning is relatively high and is also at a level where humans will suffer undesirable health effects."

www.epa.gov/ozone/snap/fire/co2/co2report.html

 

Just be careful, that's all. I have no idea what venues Jessica is touring and can think of at least one I would not use a CO2 extinguisher in.

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So hang on, if there is a SMALL fire in said venue Kerry, how would one go about fighting it?

 

I did a fire warden course not so long ago and we let off maybe 1 (2 halfs) Co2 in a 25-30 person classroom no problem.

 

A review of accidental deaths or injuries related to carbon dioxide use in fire protection indicates that the majority of reported incidents occurred during maintenance on or around the carbon dioxide fire protection system. In many of the situations where carbon dioxide exposure led to death or injury during maintenance operations, the discharge resulted from personnel inadvertently touching, hitting, or depressing a component of the system. In some cases, personnel did not adhere to the precautionary measures prescribed. In other cases, the safety measures were followed, but other accidental discharge mechanisms occurred.

 

and skimming that article does not suggest much, simply that any data they tried to get was not substantial enough

Information was requested on any incidents of death or injury resulting from the use of carbon dioxide fire extinguishing systems. Data were requested on both fire- and nonfire-related incidents; however, it was significantly more difficult to gather information on fire-related incidents. Injuries and fatalities from fire situations are generally classified only as fire-related and are not broken down by the fire suppression agent that was used. Therefore, carbon dioxide deaths and injuries from fire-related situations may not be adequately represented. In addition, it should be noted that any discharge of carbon dioxide which resulted in no injuries and/or deaths was not included in the analysis.
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Hang on a minute - what exactly are we saying here? That indoors, a fire extinguisher will displace sufficient oxygen to cause 'undesirable side effects' - isn't this exactly the same 'hazard' as the tales of musicians becoming unconscious in the pit when a couple of pea supers were going full tilt? I can't find it now, but wasn't the science behind that apocryphal danger debunked? Is 2Kg or so of Co2 from an extinguisher in still air going to have the person putting a fire out falling to the floor?

 

In all seriousness, is there any actual data on this, or is it just possible, but undocumented? In many low smoke machines using CO2, the cylinders are substantially larger, and anyone still using CO2 in Pea Soupers uses far more than a couple of Kg of dry weight in a show.

 

In a risk assessment, I'd rate the danger of burns from contact with frozen surfaces higher than even a case of light-headedness. The force with which the CO2 emerges from the extinguisher is sufficient to disturb the still air scenario in anything less than a small cupboard - on a stage the volume of CO2 seems hardly enough to reduce the oxygen content of the air by a figure significant to cause loss of consciousness .

 

I tried to work it out, but the intricacies of Boyles Law have drifted away in the dimness of time. My iffy maths suggests that instantaneously released, it would be around 750 cu cm - but it wouldn't remain in one place, and would disperse quickly. Burn risk = yes, keeling over, somehow = no.

 

Isn't this a very low risk activity. I'm suggest the main issue with the project is simply cost! A 30 second total burn isn't that long a time for repeating in shows - somebody would have to time the bursts to work out how many performances out of one cylinder!

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