Halon Fire Extinguisher?

[O. Sami Saydjari]

I just got my first issue of "Light Plane Maintenance" magazine.
I am really enjoying it. In their free book "40 Top Maintenance Tips"
(p27), they say "get the Halon extinguisher while they are still legal."

As I recall, there has been some issue that inhaling Halon can be pretty
bad for people's health. Why is a Halon fire extinguisher a great idea.

Also, this might sound dumb, but don't C02 extringuisher work by
depriving fires of 0xygen? It seems to me that in a small aircraft
cabin, one might also end up depriving the pilot and crew of oxygen as
well. Perhaps, one can survive long enough to put out the fire and then
open the air vents?!

Has anyone out there experienced an in-flight cabin fire that they put
out with an extinguisher? What was it like?

-Sami
N2057M, Piper Turbo Arrow III (being overhauled)

[Dale]

In article >,
"O. Sami Saydjari" > wrote:



> As I recall, there has been some issue that inhaling Halon can be pretty
> bad for people's health. Why is a Halon fire extinguisher a great idea.

Halon itself is non-toxic. When exposed to heat (as in a fire) some
byproducts are toxic. Also, a high concentration of Halon while not
toxic is not a survivable atmosphere. That being said, fire and fire
products are not survivable/toxic...and they also cause a lot of pain.
Use the extinguisher to put the fire out, it's the lesser of the evils.
Halon is a wonderful extinguishing agent in a confined space such as a
cockpit and it does no harm to electronics, avionics, etc.

> Also, this might sound dumb, but don't C02 extringuisher work by
> depriving fires of 0xygen? It seems to me that in a small aircraft
> cabin, one might also end up depriving the pilot and crew of oxygen as
> well. Perhaps, one can survive long enough to put out the fire and then
> open the air vents?!

Generally a handheld extinguisher doesn't contain enought CO2 to
incapacitate you before you can vent the cabin.

> Has anyone out there experienced an in-flight cabin fire that they put
> out with an extinguisher? What was it like?


No inflight cabin fires, but I worked Crash Rescue for 20 years.

--
Dale L. Falk

There is nothing - absolutely nothing - half so much worth doing
as simply messing around with airplanes.

http://home.gci.net/~sncdfalk/flying.html

[G.R. Patterson III]

"O. Sami Saydjari" wrote:
>
> As I recall, there has been some issue that inhaling Halon can be pretty
> bad for people's health.

Inhaling the contents of just about any fire extinguisher can be pretty bad for your
health.

> Why is a Halon fire extinguisher a great idea.

It doesn't damage mechanical, electrical, or electronic components of the aircraft.
This is why they also used to be common in computer rooms.

> Also, this might sound dumb, but don't C02 extringuisher work by
> depriving fires of 0xygen? It seems to me that in a small aircraft
> cabin, one might also end up depriving the pilot and crew of oxygen as
> well. Perhaps, one can survive long enough to put out the fire and then
> open the air vents?!

Perhaps so. The manufacturers are billing these as good substitutes for Halon in the
usual environments in which Halon is used on the ground.

Check the newsgroups archives for postings by Ron Natalie on this topic.

George Patterson
If you don't tell lies, you never have to remember what you said.

[Ben Jackson]

In article >,
O. Sami Saydjari > wrote:
>As I recall, there has been some issue that inhaling Halon can be pretty
>bad for people's health. Why is a Halon fire extinguisher a great idea.

Halon is a great alternative to water in indoor environments because
it's non-directional. You can't 'flood' a room with a conventional dry
fire extinguisher, but you CAN flood a room with halon. It's heavier
than air so it fills up the room and smothers the fire. That's the
reason I've been told it's dangerous to inhale -- it will sit in your
lungs.

I only deployed a dry extinguisher inside once (small grease fire) and
it was a god awful mess for only a few short bursts.

--
Ben Jackson
>
http://www.ben.com/

[Gerry Caron]

"Ben Jackson" > wrote in message
news:Ttcjc.25047$YP5.1970503@attbi_s02...
> In article >,
> O. Sami Saydjari > wrote:
> >As I recall, there has been some issue that inhaling Halon can be pretty
> >bad for people's health. Why is a Halon fire extinguisher a great idea.
>
> Halon is a great alternative to water in indoor environments because
> it's non-directional. You can't 'flood' a room with a conventional dry
> fire extinguisher, but you CAN flood a room with halon.

Sort of true, but sprinklers are quite capable of flooding a room with
water. The problem is water can cause as much or more damage than the fire
to a lot of expensive things. Then again, for people, being wet is
preferable to being burned.

>It's heavier
> than air so it fills up the room and smothers the fire. That's the
> reason I've been told it's dangerous to inhale -- it will sit in your
> lungs.

Yes and no. It is heavier than air, but it does disperse rapidly providing
a relatively constant concentration of Halon in a closed space. At "normal"
concentration levels, it's not hazardous. A properly sized Halon system
will provide a concentration of 6% to 7%. Three to 5% is all that's needed
for it to work. At those levels, there is more than enough oxygen to
breathe without any ill effects (ref: Boyle's Law). The only time there is
a potential problem is when the fire gets really hot before the Halon is
introduced. The high temps can break down the Halon creating some toxic
byproducts. I'd say it's much less of a danger than the smoke from the
fire.

Halon doesn't "smother" a fire. It breaks the chemical reaction. Think of
it as an anti-catalyst. Since it doesn't displace all the oxygen, people
can still breathe. I've been in a computer room that had a Halon system
when it was triggered. When it does, you're supposed to keep the doors
closed so that it can do its magic. The primary risks are 1) Noise - high
pressure gas venting thru little nozzles makes a horribly loud screeching
sound, 2) Limited short-term visibility - that rapidly expanding gas causes
a condensation cloud to form for a few seconds and people trying to move
quickly run into things, and 3) Debris flying everywhere - dirt and other
lightweight items pose a definite eye hazard.

> I only deployed a dry extinguisher inside once (small grease fire) and
> it was a god awful mess for only a few short bursts.

Done that too. A good whiff that stuff will leave you gagging for hours.
I'll take Halon any day.

Gerry

[Stealth Pilot]

On Mon, 26 Apr 2004 08:20:32 -0500, "O. Sami Saydjari"
> wrote:

>I just got my first issue of "Light Plane Maintenance" magazine.
>I am really enjoying it. In their free book "40 Top Maintenance Tips"
>(p27), they say "get the Halon extinguisher while they are still legal."
>
>As I recall, there has been some issue that inhaling Halon can be pretty
>bad for people's health. Why is a Halon fire extinguisher a great idea.
>
>Also, this might sound dumb, but don't C02 extringuisher work by
>depriving fires of 0xygen? It seems to me that in a small aircraft
>cabin, one might also end up depriving the pilot and crew of oxygen as
>well. Perhaps, one can survive long enough to put out the fire and then
>open the air vents?!
>
>Has anyone out there experienced an in-flight cabin fire that they put
>out with an extinguisher? What was it like?
>
>-Sami
>N2057M, Piper Turbo Arrow III (being overhauled)

Halon is a banned substance. It is an ozone depleting chemical.

[G.R. Patterson III]

Stealth Pilot wrote:
>
> Halon is a banned substance. It is an ozone depleting chemical.

In the Americas, only the manufacture is banned. There's a small industry recycling
the stuff from old systems, and extinguishers are still available and legal to own.
From what I've read, possession is banned in the EU.

George Patterson
If you don't tell lies, you never have to remember what you said.

[Ron Natalie]

Thank you George.

Neither Halon nor CO2 work primarily by depriving the fire of oxygen. Halon works by
interfering with the chemical reaction of burning. It is effective at concentrations far below
that necessary to stop free burning by lack of oxygen.

CO2 and even water for that matter gets most of it's fire fighting affect from COOLING.
CO2 is frosty cold coming out of the extinguisher and does a pretty good job of it. Any
firefighter who's worked a reasonable size fire knows it the water absorbing the heat and
turning to steam that knocks down the fire.

Remember there are four things you have to have to have a fire:

1. Fuel
2. Oxygen
3. Heat
4. Battalion Chief

Take away any one and you can't have a fire.

[Jürgen Exner]

O. Sami Saydjari wrote:
> I just got my first issue of "Light Plane Maintenance" magazine.
> I am really enjoying it. In their free book "40 Top Maintenance Tips"
> (p27), they say "get the Halon extinguisher while they are still
> legal."

Halon has been banned years ago because it is one of the worst chemicals
wrt. destroying the ozone layer.

> As I recall, there has been some issue that inhaling Halon can be
> pretty bad for people's health.

Not really. Halon is non-toxic.

> Why is a Halon fire extinguisher a
> great idea.

Because is it is non-toxic, very effective, non-corrosive, non-damaging,
doesn't leave a residue, and half a dozen other reasons.

> Also, this might sound dumb, but don't C02 extringuisher work by
> depriving fires of 0xygen?

Plus cooling the fire below the ingnition temperature.

> It seems to me that in a small aircraft
> cabin, one might also end up depriving the pilot and crew of oxygen as
> well.

Only a concern for prolonged exposure.

> Perhaps, one can survive long enough to put out the fire and
> then open the air vents?!

Normal ventilation would probably even be enough.

jue

[G.R. Patterson III]

"Jürgen Exner" wrote:
>
> Halon has been banned years ago because it is one of the worst chemicals
> wrt. destroying the ozone layer.

In the Americas, only the manufacture is banned. There's a small industry recycling
the stuff from old systems, and extinguishers are still available and legal to own.
From what I've read, possession is banned in the EU.

George Patterson
If you don't tell lies, you never have to remember what you said.

[Roger Halstead]

On Sun, 02 May 2004 16:01:47 GMT, "Jürgen Exner"
> wrote:

>O. Sami Saydjari wrote:
>> I just got my first issue of "Light Plane Maintenance" magazine.
>> I am really enjoying it. In their free book "40 Top Maintenance Tips"
>> (p27), they say "get the Halon extinguisher while they are still
>> legal."
>
>Halon has been banned years ago because it is one of the worst chemicals
>wrt. destroying the ozone layer.

It was widely used in the 70s and possibly into the 80s, particularly
in computer rooms that might contain lots of personnel.

At several installations we had large process control computer rooms
That used Halon from large tanks located on a lower floor. It's been
a while but I'd guess these tanks might have been as large as 150
gallons. They were connected to the computer rooms through either a 3"
or 4" header pipe that had a number of outlets. These outlets did not
have fuseable links, or diffusers on them as with water. They were
wide open pipes and an extinguisher dump was something you did not
want to experience more than once.

Although these rooms were large, there weren't *that* large. They
were solid and tight, separated from the processes by a "blast wall".

I saw a 1 1/2 steel door that had been bent from an extinguisher dump.
The door was open about 1/3 of the way when the dump occurred. Had
the frame not been set in reinforced concrete it would have blown the
door in a spectacular fashion.

>
>> As I recall, there has been some issue that inhaling Halon can be
>> pretty bad for people's health.

There are several "gotchas" with Halon, but "in general you can inhale
Halon with no ill effects.

It is my understanding that it works differently than other
extinguishers by inhibiting the combustion process while still leaving
enough Oxygen in the air for survival.

>
>Not really. Halon is non-toxic.

OTOH although Halon is non-toxic, at high temperatures it can generate
some very toxic gases. Really nasty stuff when it is broken down into
it's basic constituents.

>
>> Why is a Halon fire extinguisher a
>> great idea.
>
>Because is it is non-toxic, very effective, non-corrosive, non-damaging,
>doesn't leave a residue, and half a dozen other reasons.

To my way of thinking there are about the only safe thing to use in an
aircraft. Many have dry chemical extinguishers and using one of those
in a confined area is ... quite an experience. It'll leave a taste
in your mouth for quite a while, but you shouldn't suffer from acid
indigestion for a while be it a standard or Purple K (TM) charge.

>
>> Also, this might sound dumb, but don't C02 extringuisher work by
>> depriving fires of 0xygen?
>
>Plus cooling the fire below the ingnition temperature.
>
>> It seems to me that in a small aircraft
>> cabin, one might also end up depriving the pilot and crew of oxygen as
>> well.

With the airflow through most small aircraft I'm not sure the CO2
extinguisher would be all that effective.


Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

>
>Only a concern for prolonged exposure.
>
>> Perhaps, one can survive long enough to put out the fire and
>> then open the air vents?!
>
>Normal ventilation would probably even be enough.
>
>jue
>

[Jürgen Exner]

G.R. Patterson III wrote:
> "Jürgen Exner" wrote:
>>
>> Halon has been banned years ago because it is one of the worst
>> chemicals wrt. destroying the ozone layer.
>
> In the Americas, only the manufacture is banned. There's a small
> industry recycling the stuff from old systems, and extinguishers are
> still available and legal to own.

How come this doesn't surprise me?

> From what I've read, possession is
> banned in the EU.

AFAIK production and sales are illegal.
But you don't have to turn in your old extinguisher.

jue

[Aaron Coolidge]

Roger Halstead > wrote:
<snip>

: With the airflow through most small aircraft I'm not sure the CO2
: extinguisher would be all that effective.

I was in the engine room of a cargo ship that had a CO2 extinguisher -
technically called a "smothering system" activate. Let's just say that
you *DO NOT* want to be anywhere near a CO2 system that's been activated.
As I recall, two men who couldn't get out were killed. The ship's engines
stopped within a minute due to lack of oxygen. I would *NEVER* shoot off
a CO2 extinguisher in any kind of confined space.
--
Aaron Coolidge

[Don Tuite]

On Mon, 03 May 2004 14:19:12 GMT, "Jürgen Exner"
> wrote:

>G.R. Patterson III wrote:
>> "Jürgen Exner" wrote:
>>>
>>> Halon has been banned years ago because it is one of the worst
>>> chemicals wrt. destroying the ozone layer.
>>
>> In the Americas, only the manufacture is banned. There's a small
>> industry recycling the stuff from old systems, and extinguishers are
>> still available and legal to own.
>
>How come this doesn't surprise me?

So what's to become of your existing stocks?

No idea? How come this doesn't surprise me?

Don

[Roger Halstead]

On Mon, 3 May 2004 14:50:56 +0000 (UTC), Aaron Coolidge
> wrote:

>Roger Halstead > wrote:
><snip>
>
>: With the airflow through most small aircraft I'm not sure the CO2
>: extinguisher would be all that effective.
>
>I was in the engine room of a cargo ship that had a CO2 extinguisher -

I would think the cargo hold would be a lot tighter than the typical
small plane where the draft would blow out a match.

>technically called a "smothering system" activate. Let's just say that
>you *DO NOT* want to be anywhere near a CO2 system that's been activated.

About the only one safe for a confined space is Halon. You'll choke
on a dry chemical. The stuff is terrible even in an office, let alone
an airplane.

>As I recall, two men who couldn't get out were killed. The ship's engines
>stopped within a minute due to lack of oxygen. I would *NEVER* shoot off
>a CO2 extinguisher in any kind of confined space.

I once was able to put my yearly training to use when we had a fire in
one of the construction trailers on site.

It was Winter and very cold. They had one of the old style Kerosene
stoves that were used in many homes. For safety it was set in a metal
pan about an inch to inch and a half deep. Thing was probably 4 feet
wide, two and a half across and maybe three feet tall. Of course it
was located way back at the end of the trailer which made good sense.

They had flooded it and when it started it got hot in a hurry, plus
there was a good half inch (or more) of kerosene in the pan. The
flames were boiling up and then following the ceiling about 20 feet to
the door where they were rolling out.

I had a 25# dry (Purple-K) extinguisher in each hand. I took a deep
breath and went in on my knees. (standing up would not have been
conducive to good health. It looked just like the training films with
the flames billowing across the ceiling the full length of the
trailer).
I don't remember how many extinguishers the construction crew had
used, but there were a bunch of them on the ground by the door. They
had been trying to put out the flames instead of the fire. It took
less than the one extinguisher to put out the fire, but that kerosene
was boiling hot and was filling the room with fumes... fast. As soon
as the flames were out, so was I. <:-)) If that sucker relit it was
going to be noisy.

I was able to hold my breath long enough to go in, put out the fire,
and get out. With the heat and fumes, breathing in there would not
have been healthy. (It was Hot!)

You never, ever use CO2 in any confined space. That would be pressure
vessels, holes in the ground, and air tight rooms. They are fine in
the normal open office spaces.

CO2 does warn you though. It makes you feel like you need to breathe.
It is what keys, or triggers the breathing reflex, not the lack of
Oxygen. For instance with nitrogen in a confined space you have
absolutely no warning. You just go to sleep. Hence the requirement
for the complete harness and an outside safety man when entering
pressure vessels or holes in the ground.

We had a number of underground pumping stations. When I hired in,
we'd just go out, open the hatch, go in and check the instruments. By
the time I went back to college we couldn't even go in alone.
Complete harness and outside backup were minimum.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com