How Do You Empty an Old Fire Extinguisher?

[Davo]

Because I found one at the tip with no propellant but you can hear the powder moving inside if you tilt the extinguisher back and forth.

I was just wondering if the powder is dangerous in some way. I didn't want to take the valve off, dump the powder into a bag and then find out later on I shouldn't have!

It looks like an ABC extinguisher - it says: "Use Total Walther Pulvex ABC Royal Dry Powder Extinguishant" on the label.

I'll use the canister itself later on as a compressed air source or maybe for pressure-bleeding brakes.

[JDNSW]

The powder is most likely one of the following (courtesy Wikipedia):-

* Monoammonium phosphate, also known as ABC Dry Chemical, used on class A, B, and C fires. It receives its class A rating from the agents ability to melt and flow at 177 °C (350 °F) to smother the fire. More corrosive than other dry chemical agents.
* Sodium bicarbonate, used on class B and C fires. Interrupts the fire's chemical reaction.
* Potassium bicarbonate (aka Purple-K), used on class B and C fires. About two times as effective on class B fires as sodium bicarbonate. The preferred dry chemical agent of the oil and gas industry. The only dry chemical agent certified for use in AR-FF by the NFPA.
* Potassium bicarbonate & Urea Complex (aka Monnex), used on Class B and C fires. More effective than all other powders due to its ability to decrepitate (where the powder breaks up into smaller particles) in the flame zone creating a larger surface area for free radical inhibition.

In any case will not be anything dangerous - don't forget that it is intended to be spread round freely. At worst it will be a mild irritant. My guess is that it is probably sodium bicarbonate (cooking soda).

On the subject, it is worth noting that two types of fire extinguishers pose special risks:-
You may occasionally find carbon tetrachloride extinguishers - these usually have attractive brass cases and a hand pump. Carbon tetrachloride, although used extensively in fire extinguishers up to the 1950s, particularly in vehicles, is a cumulative poison with severe health effects - avoid contact with it or breathing its fumes.

You may also come across halon extinguishers. These may also have an attractive brass case or will be painted all over yellow. It is an offence to discharge these or even to possess them, except for a very few specific uses, the only one I know of is as a cockpit extinguisher in aircraft. However, the agent is not poisonous - it is ozone depleting.


John

[mcrover]

As above, it's just Bicarb soda so put it in boiling water and clean your battery terminals.

[numpty]

The only place you're likely to find BCF/Halon these days, as John says, is in aircraft, as they have been phased out everywhere else. It may not be poisonous per se John, but as it displaces oxygen, you are unlikely to be able to breath in a cloud of it, which does make it life threatening. Mind you, DCP has a similar effect. They say it is non toxic, but you'll struggle to breath with a lung full of it.

[Bushwanderer]

From the label,
"Use Total Walther Pulvex ABC Royal Dry Powder Extinguishant",
I think that is monoammonium phosphate (ABC).
Best Wishes,

[JDNSW]

The only place you're likely to find BCF/Halon these days, as John says, is in aircraft, as they have been phased out everywhere else. It may not be poisonous per se John, but as it displaces oxygen, you are unlikely to be able to breath in a cloud of it, which does make it life threatening. Mind you, DCP has a similar effect. They say it is non toxic, but you'll struggle to breath with a lung full of it.

The other place you may find them is on a tip - which is where the one in question came from. And I have seen them in clearing sales fairly recently!

And as you correctly state, they are not poisonous, but will displace air, and hence are an asphyxiation risk in enclosed spaces - although only if unventilated, as they are approved for use in aircraft cockpits.

John

[numpty]

The other place you may find them is on a tip - which is where the one in question came from. And I have seen them in clearing sales fairly recently!

And as you correctly state, they are not poisonous, but will displace air, and hence are an asphyxiation risk in enclosed spaces - although only if unventilated, as they are approved for use in aircraft cockpits.

John

True John, but they don't have a pleasant aroma:( and are /were an overkill when used on a "oh my god the chips" scenario.

They were used a lot in computer rooms and underground engine rooms etc as a flood system. And in those places, they really were a health hazard......only if they were activated of course.;)

[harry]

just a correction to a couple of posts,
davo states in the first post that the extingushant is 'dry powder'
so no halon, this was not an aircraft ext.
if the ext still has a charge, and the only way to safely find out is to pull the trigger,
then find a large clear area in open air and pull the trigger, it is not illegal to discharge a dry powder ext.
if after pulling the trigger nothing happens, then unscrew the top and dispose of the powder carefully in a bin - outside.
as a footnote - if anyone still has a halon extinguisher - don't use it [although it will still put out a fire!!] it is an ozone depleting substance and there are huge fines, very huge, very very huge, for discharging it - anyone with one now must apply for a dispensation to have one if it is not installed in an aircraft .

[Davo]

Well, I thought the combined knowledge here would sort that one out! :D

Thanks for that. There are that many odd chemicals around these days I knew I had better check.

[JDNSW]

just a correction to a couple of posts,
davo states in the first post that the extingushant is 'dry powder'
so no halon, this was not an aircraft ext......


Noted - information about CCl4 and halon extinguishers was added as a warning while on the subject of old extinguishers. In my view the CCl4 extinguishers are particularly hazardous because they are attractive bits of brassware, which means they are likely to be messed with. While very few of them are likely to still contain any CCl4, there are probably a few about that do.

John

[amshaw]

- if anyone still has a halon extinguisher - don't use it [although it will still put out a fire!!] it is an ozone depleting substance and there are huge fines, very huge, very very huge, for discharging it - anyone with one now must apply for a dispensation to have one if it is not installed in an aircraft .

Last time I heard it was $10,000 for having one and $20,000 for using it.......:angel:

[malleefowl]

If you're not sure why not take to the local fire station?
i'm sure they will help out and may have some available for air cyl etc.
regards,Mary

[knp]

Hi

This may be too late but if it looks servicable and you haven't discharged it yet why not use it to practice on a fire? Great fun and handy to know.

Unless, of course, it is a yellow cooloured extinguisher (BCF) in which case just hand it in the a fire station or a fire extinguisher mob. As someone already has said, the fines are hefty and the amnesty finished ages ago.

When it's empty, don't throw the valve away as you will need it to doctor up the air line etc that you want. The threads on the necks of these are rarely common.

Cheers
Peter

[Mick-Kelly]

When i worked at the museum it had a halon system (labs and storage). We were told if it went off you had about 60 seconds before you couldnt breath.

[CraigE]

They are not bicarb as stated, may have it in as a component but not soley bicarb. Usually one of the other 3 as mentioned but possiblly up to 5 different types of DCP. Do not use the contents on anything you value. DCP ingredients are corrosive, not to the point of being hazardous, but corrosive none the less and destroy electrics.
If the charge is completely gone, the valve can be unscrewed and contents flushed out. However be ready for any residual charge and unscrew carefully.

[CraigE]

Last time I heard it was $10,000 for having one and $20,000 for using it.......:angel:
Only in Australia. You will not be fined if you hand them in, but if you are caught with them here.:twisted:
Still used on international flights.

[DEFENDERZOOK]

When i worked at the museum it had a halon system (labs and storage). We were told if it went off you had about 60 seconds before you couldnt breath.



yep....thats right......

what it does is take all the oxygen out of the room.........
one of the 3 requirements for a fire to burn.....
the other two are fuel and heat........


it works great for putting a fire out.....but unfortunately....oxygen is
also one of our requirements to live......