Fire extinguishers: smoke, fire, and kitchens

[Thomas Prufer]

All this talk of smoke detectors in kitchens reminded me of something I saw in the US: an automatic retrofit fire extinguisher for domestic use.

Two small tins are stuck to the bottom of the extractor hood with magnets. Something that looks like the fuse of a firecracker sticks out the bottom of each. A grease fire lights the fuse, and this causes a load of extinguishing powder (baking soda?) to be dumped. Cost is ~45 US dollars a pair...

While it is not a cure-all (for instance, it's "not for gas ranges"), it is a simple solution, cheap, a false alarm not more damage that a considerable mess, and overall something I would like to have thought up myself.

Thomas Prufer

[Jethro_uk]

Many years ago, the oil-fired heater my Dad had in the workshop had a cutoff valve that was held open by a soldered joint that was strung over the combustion chamber feed. Above the temperature to melt solder, the joint would "pop" and the valve close.

[Martin Brown]

Wouldn't it be easier to own a normal domestic fire extinguisher. The main thing to remember is aim low to hit the base of the fire and the first time you ever use one be prepared for the *LOUD NOISE*.

Chip pan fires can be relatively easily smothered but are utterly lethal if you make the mistake of adding water. The Fire Brigade do an impressive travelling show of how to and how *NOT* to do it.

The latter being far more entertaining to watch.

[Jethro_uk]

Mythbusters supersized it - very impressive/scary

[harry]

The best thing for chip pans is a fire blanket. Does anybody have chip pans these days?

[Nick Odell]

I wonder how it would cope with stir-fry?

Nick

[NY]

Oven chips have supplanted a deep chip pan - except in the local chippy!

The things to remember with a chip pan fire are:

- turn off the heat: surprising how many people forget that in their panic!

- no water: repeat that until you are blue in the face - NO WATER

- do not pick the pan up to take it outside where it can burn itself out: if you trip in the panic, you'll spread the fat and the fire far and wide; as you are carrying it, the flames will tend to blow backwards towards you; as you open the door there could be a gust of wind which will blow the flames towards you

- cover it with a fire blanket if you have one

- if not, run a towel under the tap and then squeeze it out to leave it moist but NOT DRIPPING WET

- hold the towel so the edge covers you fingers and lay it with the front edge of the pan covered first, then the back - you don't want to channel the flames towards you

- leave it for a long time, even after it looks as if the flames have been extinguished

- call the fire brigade

- ideally, find a large non-flammable board and lay that over the top to make sure that all the air is excluded (the damp towel or fire blanket will do this to some extent but not perfectly)

And if you remember all that while you are panicking, you're probably superhuman!

[Robin]

<seasonal_chorus>

Oh no they've not!

</seasonal_chorus>

They've just gone electric - albeit that does reduce the risk of fire.

[newshound]

A former colleague of mine completely wrote off a new kitchen that way. His PhD didn't help him much that time.

[NY]

Also, you need to be careful with a fire extinguisher. You don't want the spray of CO2 from the nozzle to blow droplets off the surface of the fat, spreading the fire. Better to discharge the extinguisher into a bucket - being heavier than air it will stay there and you can pour it as if it was water onto the fat from above - taking care not to set the bucket on fire :-)

But I'm not sure how well it will work because the heat of the fire and the hot combustion gases may prevent the CO2 from landing on the flames.

[Harry Bloomfield]

NY presented the following explanation :

We like proper chips from a chip pan. It has two lugs to pick it up, which when in use get very hot, too hot to attempt to lift were it to catch fire (good thing). We have a heavy solid hard wood chopping board alongside the gas hob, which is perfect to drop straight on top of the pan, should it ever catch fire.

[alan_m]

I wonder if the problem with that type of device being above the hob means that the trigger mechanism it will become very degraded over a short period of time with a mix of steam and atomised grease from normal cooking. Both will carry the dust from the atmosphere and deposit it on the fire supression device. Consider how dirty the grease filter in an extractor hob can get.

Furthermore once the flame reaches the bottom of the extractor hob will not the grease filter also catch fire?

[Thomas Prufer]

Probably not at all -- or really well, depending on how one defined "coping":-) But neither would a smoke detector cope with it, and I have my doubts about a heat detector. A good stir-fry needs a fair bit of heat output.

Burners for woks max out at about 80-90 kW. This means gas (and probably need serious airflow/extraction kit, too).

Thomas Prufer

[ARW]

Try doing a small extension in Wales.

https://gov.wales/topics/planning/buildingregs/approved-documents/part-b-fire/?lang=en

It killed the building trade and England might be next.

[tabbypurr]

I presume the fire will soon re-ignite, but it does buy time.

NT

[Thomas Prufer]

And I thought the Germans were specialists in over-regulation.

I like these range-cooker-firethingies because they are cheap, removable, unregulated, and might work. On the same level as keeping a large lid near a chip pan...

Thomas Prufer

[The Natural Philosopher]

Holy carp. Sprinkler mandaatory in welsh new builds? Is that REALLY what yhye said?

There must be a sprinkler manufacturer whose relatives work in Welsh local guvmint...

[Robin]

Yep, first country in the world to do so. It wasn't cost-effective by the usual criteria[1] with each life saved costing over £m6. But that wasn't public expenditure. So what's not to like in that for Ministers when the public think it's some other bugger's money that pays for it (and in Wales are very often right)?

The Scottish government have promised to make them compulsory in all new social housing. (IIRC some councils in Scotland do so already.)

Westminster Ministers - to their credit - have so far resisted pressure to follow Wales in England. But it doesn't help when coroners call for "Immediate and positive consideration of the compulsory inclusion in the design, planning and building phases for residential properties..." with, as usual, no mention of the costs and opportunity costs.

And if anyone's considering DIY, AIUI a tank in the loft and a pump are almost obligatory as water companies won't guarantee high enough mains pressure.

[1]

[alan_m]

The problem could be that if the regulation specified fire suppression equipment insurance companies may/would insist on formal yearly inspection before insuring a property. The use of unregulated devices may not be acceptable to an insurance company.

[ARW]

The AICO rep that presented my installation course suggested that one reason the English have not gone down this route is due to the lobbying of house builders.