Using a C02 fire extinguisher on stage

[ramdram]

Somehow I cannot see a fire bottle manufacturer issuing a warning for the firefighter to assess the volume of the room before they tackle the blaze.

 

The fire is burning the oxygen at a hell of a rate, there's possibly really, really nasty noxious gases flowing off the fire, coming off the old plastic junk in the room, plus the stuff in the synthetic carpets and rubber type underlay.

 

You could not rely on the fact the furniture is constructed of the "new" fire retardant compounds, because you don't know and you are fairly unlikely to look at the foam filling label to see if its kosher. In short that added zing of CO2 really won't make a huge difference.

 

The cardinal rule we had was unless the fire was really tiny or in a metal waste paper bin and you were really confident then simply FOO. Shut the door and raise the alarm.

 

The Beeb firemen were very pragmatic...their view, "why be a dead hero?"

 

There is quite a difference between fighting a fire using up an entire CO2 bottle and for an actor to give a couple of short puffs. The CO2 being heavier than other gases will sink to the stage and gradually mix with the air.

 

Even if a cloud of CO2 flowed into the pit it would still be on the floor of the pit. I suggest it would take rather more than a couple of puffs of CO2 to asphyxiate the entire orchestra.

 

Don't forget we as human beans are constantly exhaling CO2 anyway. Anyone travelling on the tubes in rush hour must be swimming in the stuff.

[DrummerJonny]

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

Surely in that situation, the risk posed by the fire would be greater than that of the extinguisher discharge?

 

There is (in my opinion) a world of difference between discharging an extinguisher to extinguish a fire and discharging one as part of the show with an audience (not in the process of evacuation for the pedants) in the house.

 

 

 

[Shez]

Is there a comparison to be drawn here with the CO2 jet systems out there? They tend to be used in multiples, and would appear to produce a greater volume of gas per second than an extinguisher. Is there perhaps an RA out there for them?

[dbuckley]

Tangential rather than off-topic, I've been considering using CO₂ fire extinuishers as an alternative to CO₂ jet systems, simply because the solenoid valves required to constuct the jet system are eye-wateringly expensive. OK, the extinguisher approach is distincly low-tech and not as cute control-wise as a solenoid, but looking acceptable.

[Ynot]

Tangential rather than off-topic, I've been considering using CO₂ fire extinuishers as an alternative to CO₂ jet systems, simply because the solenoid valves required to constuct the jet system are eye-wateringly expensive. OK, the extinguisher approach is distincly low-tech and not as cute control-wise as a solenoid, but looking acceptable.

Indeed.

I went through a lot of searching before the aforementioned panto where we needed multiple CO2 'jets' before I settled on the low-tech option of using the out of date extinguishers. Personally I'd say this is really a no-brainer for the OP - just contact a local service company (maybe even the venue's own...) and talk nice about some older units.

[kerry davies]

Did I say don't do it?

I said it can be hazardous in confined, unventilated spaces and if any of you have had fire warden training that did not make this clear then the training was flawed.

 

Paul, a 2Kg bottle produces between 1.1 and 1.2 cubic metres and 17% is the 'fatal' level so the space is about 2m by 2m by 1.75m. The BS on extinguishers actually 'bans' siting them in small rooms and cupboards and manufacturers have warnings in their instructions on use.

 

You do have more chance of getting a burn but the consequences of the lower incidence risk of asphyxiation should be considered. I have no idea what conditions we are talking about, the set could be enclosed, the tour could be to tiny venues, I don't know.

 

The fact that people do not know there is a risk, however small tells me a lot about theatre H&S training that is worrying, can't they read what fire extinguisher suppliers write?

Carbon Dioxide can lead to asphyxiation if found in quantity in confined spaces, so take care to ventilate the area as soon as the fire is under control.

 

In a work environment, no-one should use a fire extinguisher unless they have received the appropriate training.

[Sully]

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?

 

CO2 actually has toxic effects above a certain percentage in air which will be an issue long before oxygen displacement, oxygen displacement is more of a hazard with non-toxic (to inhale) gases.

 

David.

[jessicathanki]

For each show we need three short bursts. We are touring to Soho theatre, Plymouth Drum, Kala Sangum Bradford, MAC Birmingham and Manchester Royal exchange. We have tried in rehearsals and it works well. But not sure how long this fire extinguisher will last. We have used it once, 3 bursts. Cost is a very big issue.

[scjb]

I've just read that breathing produces carbon dioxide... bloody dangerous if you ask me.

[ramdram]

Ref the size of rooms IIRC the advice for tackling a suspected fire in a cupboard/storeroom was to raise the alarm first, no question.

 

There was mention about touching the door handle with the back of your hand, to assess the heat being transmitted through the door, although unless you were seeing cupboard fires every day how would you know how bad the fire really was? Or see if the paint or varnish is blistering on the outside. That probably would give you some idea.

 

On no account were you to open the door "just to see" in case of a flash burn event as the "new" air with its 20% O2 rushed in adding fuel to the fire.

 

Again the advice from the Beeb firemen..."You did the right thing by raising the alarm, now FOO".

 

We all went through fire extinguishing practice, with various fires and different extinguishers. We had very few types other than CO2.

 

However, once we had all extinguished the small, completely unrealistic fires, such as propane bubbling through a water bath in controlled conditions outside...nowhere near a building...the Beeb FO would look at us and simply say, "actually lads, what really happens is you raise the alarm first and then (as mentioned above) FOO".

 

Unless you knew the contents of the cupboard/storeroom intimately you could never know if some person had stored their pyros or thinners in there.

 

So the notion of fighting a fire, in a confined space, with possibly poor visibility, breathing possibly very hot noxious gases, face burning, eyes streaming, nose running, coughing your guts out, on your own, with a single fire bottle, which will last for possibly 30 seconds tops, is not really going to happen, not if you've got any sense.

 

Still less likely is anyone going to be calculating the composition of the air...allowing for that extra dash of CO2...and wondering if it's a toss up whether you die from CO2 poisoning or asphyxiation. By that time I would be in my muster position on the far side of the car park...awaiting the arrival of the F&R bods...hopefully along with the rest of you.

[Ynot]

Ref the size of rooms IIRC the advice for tackling a suspected fire in a cupboard/storeroom was to raise the alarm first, no question.

All very interesting, but off topic for the OP.

 

TO the OP I refer back to my earlier points - which should hopefully yield FREE options if they're feeling generous...

[Wuddy]

Not many of you too familiar with night-club chillers then? And this,15 seconds in,is a little one link

[ramdram]

Looks to me like those young folk were either trained to breathe pure CO2 or hold their breath for five minutes.

 

All joking aside, it occurs to me, apart from cooling off the punters and adding another sensation, visual and sort of tactile, to their night out, you could diffuse a "situation" from getting out of hand by literally cooling off the hotheads.

 

Might make it easier to see those green lasers...

 

Well then, that shows that the advent of a steep hike in the local air's CO2 content is not such an issue...providing the venue is quite airy and presumably the air handling system is rated to do the job.

 

In which case it looks as if the one or two puffs of CO2 planned for the fire extinguishing scene poses no real threat to the health of actor, cast, crew or punters...getting me nicely back on topic.

[Brian]

Not many of you too familiar with night-club chillers then? And this,15 seconds in,is a little one...

Indeed they are.

 

I was doing my best to empty 8 99kg CO2 cylinders on Friday evening. Almost managed it.

[WiLL]

The saturation levels of CO2 needed to cause harm to humans is enormous comparitively speaking, and easily avoided bythe people in the fog standing up as CO2 fills rooms from the floor upwards. Did a calculation with a scientist pal of mine once where we worked out to fill our orchestra pit with CO2 to the point where evacuation was necessary would take a staggering 38kg of dry ice in solid form, and for all the doors to be closed in the pit.

As to CO2 extinguishers having no visible effect, well... I would seriously consider having your extinguishers refilled ;P