Dry Powder extinguishers are DANGEROUS on yachts.

[prv]

Blast your fire quickly with what you have, and more importantly, GET OUT

Where to?

Pete

 

[Ricd]

What you seem to be overlooking in urging the purity of your argument iss that in any fire the rush of air will introduce breathables and diminish the concentration of CO2 around the operator to likely bearable strength.

If anyone reading your contribution is persuaded to stick with powder cylinders you will have done no one any good whatever, however satisfied you might feel about your references.

PWG

Thank you. We all have our opinions. One fact - suppliers of CO2 extinguishers state that they should not be used in confined spaces -I regard below-decks on most pleasure craft as a confined space. If there is an issue with powder then as others have suggested foam is an option.

 

[Salty John]

I used a dry powder extinguisher to put out a fire in our engine bay when we were struck by lightning. Yes it was messy, but I was in control the whole time, no white-out, no noxious fumes and I stayed inside the boat the whole time (huge lightning storm raging outside!). I was impressed at how simple it was, but we were vacuuming up white powder for a couple of hours.

 

[kesh]

Re CO and CO2
For what it is worth

the long term and short term occupational exposure limits for carbon monoxide are 30ppm and 200ppm respectively.

The limits for carbon dioxide are 5000ppm and 15000ppm. ( 0.5 and 1.5% !)

Those figures would seem to indicate that CO is considered to be far more dangerous than CO2

The concentration of CO2 in the earth's atmosphere is greater than even the short term OEL for CO

lets not discus spherical heating. those CO2 ppm are a bit weird, i mean, the breath you exhale is 5% CO2. so no rebreathing air in a paper bag when having a panic attack. and none of that breathing in while french kissing

some of the confusion about C02 is because in a fire C02 is there as a result of oxygen not being there. 20% CO2 due to fire means almost all the oxygen has been consumed and turned into C02. but filling a cabin with 20% C02 from an extinguiser means a lot of oxygen is still around to sustain life

 

[Sans Bateau]

A sobering thought, fire on board a boat.

Having done a little poking around on Google, 'porridge lung' came up with nothing except this thread. I could find nothing that indicated there were any particular health threats that were greater than the fire itself associated with either Co2 or dry powder fire extinguishers. Halon is the product still used on aircraft extinguishers.

Having said this, I have a boat that will not sink, however I do carry a liferaft by the back door, incase of fire. I can buy another boat.

 

[VicS]

those CO2 ppm are a bit weird, i mean, the breath you exhale is 5% CO2. so no rebreathing air in a paper bag when having a panic attack.

Not for 8 hours, no!

Try a poly bag over the head for 8 hours! I understand that in the early stages there are some interesting effects

 

[oldharry]

Old Harry,

Do you have any info on the 'new chemical ext.' that was recommended?

Thanks

John G

No, I did ask, and he didnt know much more about it himself, as he reckoned it had come in since he left the Fire Brigade. From his description it sounded somthing similar to conventional foam, but much thicker, and with a more active flame inhibitor. Apparently you have to go on applying a fairly thick layer for the fire to stay out, so perhaps not as good as it might be?

Re 'Porridge Lung': not anything any of us had heard of before and some of the team are quite well up on medical things. From his description it was not the result of just breathing a dusty atmoshphere, but inhaling the dense white cloud of dust discharged by an extinguisher. Presumably this is something like 20- 30% solids. But I am guessing there.

 

[dmmbruce]

FWIW, I heard the term 'porridge lung' 40+ years ago in connection with grain and sawdust 'flower', meaning fine dust. (All to do with the problems of spontaneous combustion in sunlight.) It was just a colloquial nickname for some long mock latin medical term for a nasty bronchial condition. It specifically only related to organic matter. This was said to grow some fungal spongy material in the lungs. Inorganic matter was not a risk, they said then, either for combustion or the 'porridge lung'.

Incidentally, I can vouch for the mess caused by powder extinguishers, and the long long process of trying to clean up! But it worked, fast.

 

[little shack]

some interesting points in all those posts.In it's very nature all fires are different eg afuel fire requires a certain approach smotheringor chemical inabition. electrical smothering co2 is advised but is poor on MOST otherfires unless you can drive the o2 levels way down and keep them down while the material naturaly cools otherwise you will get a reignition with just an empty extinguisher for company. Ibelieve some chemicals in dry powder are toxic they do make alot of mess but they will put outmost fire .as for the mess ect you can always clean that up.it is the smoke that will take you down very very quick .It is easy to say but more difficult to do try to stay calm and use the extinguishing agent the way it was designed and for the appropriate fire maybe dp or foam for fuel or plastic and smallco2 for wiring

 

[PerformanceSailor]

Powder on the loose

I have some "dry powder" photos in this thread on another forum.
http://www.ericsonyachts.org/infoexchange/showthread.php?t=5016&referrerid=28
I am still finding patches of dry power in remote bilge areas, this year.
Good stuff for its intended purpose, but Lord, what a mess!
LB

 

[Ubergeekian]

There is a liquid phase at very high pressures. The CO2 in presurised bottles must be in solid form though.

To go from solid to vapour (or vice versa), CO2 must be below its triple point, which is -56.4C and must be at less than 5.2 bar. At room temperature (20C) carbon dioxide makes a perfectly normal liquid-gas transition at 57.3 bar. To solidify it at that temperature takes something of the order of 8,000 bar.

 

[Ubergeekian]

Halon was stopped ( EXCEPT Military Use ) as its a so call greenhouse gas & for no other reason

It was phased out because, like all CFCs, it causes immense damage to the ozone layer. That's a completely different issue.

 

[theforeman]

.....If you get a blocked up nose ........, stroking pussy ....

i find stoking pussy has quite the opposite effect on my nose

 

[sailorman]

It was phased out because, like all CFCs, it causes immense damage to the ozone layer. That's a completely different issue.

what i said stands the Military are still able to use it

 

[Anwen]

To go back to the title of the original thread, I would say that fire is DANGEROUS on boats, and therefore the main principle is to have one or more extinguishers on board.

Nobody has talked about the composition of dry powder other than to refer to it as a chemical - it is in fact sodium bicarbonate which you can buy from the bakery section in the supermarket (along with flour). It has some other additives to improve the free-flowing properties ie make sure it comes out when you squeeze the trigger, but these are present in very small amounts.

I would be quite happy to use one of the size I have on my boat to put a fire out - the quantity released will be comparatively small and the exposure time short. I would also have more faith in a dry powder extinguisher than a CO2 unit, and I have used both types on flammable liquid fires for real. As another poster has said, a CO2 extinguisher will throw a burning liquid around, but they are good for small electrical fires.

Frankly, compared with death, I'd rather clean up some powder in my boat (and NaHCO3) is water soluble).

 

[planteater]

Frankly, compared with death, I'd rather clean up some powder in my boat (and NaHCO3) is water soluble).

A couple of weeks back I tested a time expired (1995) powder extinguisher on my patio. It worked fine but made far more mess than I had anticipated. Before I got around to cleaning it up a rain shower simply washed it away.

 

[Haven't-a-Clue]

Some interesting and conflicting statements here re carbon monoxide - CO - and carbon dioxide - CO2. A few facts here as I had to learn them as part of my training: CO2 kills by asphyxiation, ie displacing the oxygen the brain and vital organs need to function. It combines with haemoblobin at roughly the same rate as oxygen does, so it is NOT instantly lethal. That's what respiration at its' basic and scientifically correct definition is. You breath in air approx 20% oxygen -O2 - and 0.04% CO2 (and of course, nitrogen, although we'll dismiss that in our discussion). You breath out oxygen approx 16% and CO2 approx 4%, a straight gas exchange (remember I use this kind of meauring equipment every day as part of my job, so I know the numbers). Therefore, we can sort of presume that O2 and CO2 have roughly the same ability to combine with haemoglobin. So when you're exposed to a high level of CO2, respiration depth and rate increase and
you start coughing, that's the signal to move higher, above the level of CO2 (heavier than air). CO, however has 15 times the ability of both O2 and CO2 to combine with haemoglobin..............so one good lung full is the equivalent of 15 deep breaths of CO2 and you don't usually survive, very difficult to reusus someone with CO poisoning 'cos of the amount of carboxyhaemoglobin that has to be got rid of, whereas CO2 can be replaced fairly quickly with oxygen. It's one of the ways we wake people up after anaesthesia, replacing the anaesthetic agent with oxygen. Hope this helps to explain the difference and dangers between CO and CO2.

Ian

 

[ianabc]

Aqueous Foam...

1. Aqueous foam is considered by some to be most effective and a fairly non toxic and effective fire fighting foam for vehicles and boat fires.... inexpensive but not widely available.


2. Halon is I believe still allowed in in the USA but not not now available new.

3. Halon replacement, not as effective, FM 200 / FM 220 are widely available and expensive one is considered more toxic than the other.

 

[geoffatstanpit]

I thank DeepJoy for confirming what I had read somewhere but couldn't put my finger on, that the powder is Sodium Bicarbonate.

Then I remember that dry powder extinguishers work because when Sodium Bicarbonate gets hot it turns into Sodium Carbonate, water, and lots of Carbon Dioxide!

So it works mainly by smothering the fire with carbon dioxide, but concentrated in the hotspots where it does most good.

I'll stick with dry powder.

 

[Vara]

On previous posts on this subject I have advocated AFFF extinguishers as probably being the best for boats which have an engine (fuel).

Voted with my feet, I now have 2 AFFF, 2 Dry powder, a fire blanket and in extremis a bucket with a lanyard.

Only drawback is that Aldi et al don't do cheap AFFF

As an aside, took a dry powder extinguisher off the boat which looked as if it was installed as original equipment, (instructions in Swedish and no CE or other marks) so it was probably 22 years old, fired it off behind the garden shed and it worked really well!