Portable fire extinguisher rating tests

[Tom Sutton]

I am aware of the rating tests for class A and B but I came across the following statement,

“Class F relates to cooking oil and cooking fat fires. There are 4 benchmark tests using 5, 15, 25 and 75 litres of sunflower oil. The oil is heated to auto-ignition and allowed to pre burn for 2 minutes.  Fire is extinguished and no re-ignition shall occur within 10 minutes of extinguishing the fire.”

I would like to know if it is authentic and where it originates from I haven’t checked out BS EN 3-7 2004 + A1 : 2007 which may be the source or the previous standard BS 7937 ?

[wee brian]

I saw a bloke doing these test once.

They are done in a big shed. Its a standard fire put out by a bloke who does this regularly and who wears PPE. So it isn't very representative of the reallity of someone picking an extiguisehr up in an emergency and having a go.

In it's defence the fires are quite big, much bigger than a civilian would reallisticaly have a go at. So there is a factor of safety.

[AnthonyB]

It's from BS7937.

None of the fire-rating tests relate to real life use, be they A,B or F - I have footage of many of these tests (some of which is on my extinguisher related Facebook Group). They all involve the wearing of full PPE and the A fire is not the normal shape you would find. PPE is vital as you will be almost touching the crib on the A test & can dip your toe in the fuel in the B test.

A & F tests are always indoors, B tests are often outdoors, but some are done inside too.

[Tom Sutton]

Thanks Guys

Has it not been transferred from BS 7937 to BS EN 3-7 2004 + A1:2007 if it hasn’t, then it will not be a BS test anymore?

[AnthonyB]

It has indeed been incorporated into BSEN3 in virtually identical form to when it was in BS 7937.

Note from EN3 for extinguisher companies still thick enough to put non F rated extinguishers into kitchens:

"Powder and carbon dioxide fire extinguishers should not be used on Class F fires as their use on this type of fire is considered hazardous. For this reason powder and carbon dioxide fire extinguishers shall neither be tested according to this annex or marked with the "F" pictogram."

So don't put them in there on their own!

It does leave the door open for Foam - AFFF spray doesn't really work, but I'd be interested to try FP or FFFP through a low expansion branch pipe and see if it would pass at least 5F.

[Tom Sutton]

Thanks AB I shall now include on my website and soon check out BS EN 3 for the full details.

[Psuedonym]

I visit kitchens whilst servicing/repairing/installing Ansul/Amerex suppression systems on a daily/nightly basis and I kid you not, there are one hell of a lot of kitchens without a portable F class installed.
Plenty of blankets and co2's/powders/foams are still protecting (er.. fire blankets , protecting..??..) thier staff and wonderful cooking equipment (take a look sometime, you may not want to eat in your favourite restaurant/hotel afterwards though...such cleanliness, such condition of cooking equipment. (?) ) The majority of which haven't got a clue of how or what to use in the event of a fire.

I suspect servicing companies are recommending class F but not pressing for their installment effectivly enough. The majority of engineers out there are not selling with time spent talking to clients as this is not cost effective for them. Clients don't want to spend and if they have passed their RA or insurance companies requirements then they arn't going to be swayed by an obvious commission grabbing service engineer. A hotel manager is duty bound to save, save, save and honest persuasion doesnt always work.

[AnthonyB]

Speaking to my US counterparts on my Facebook extinguisher group they have a similar problem & are stuck with 6 litre & 2 gallon units - at least we have the 2 and 3 litre models to lower the cost for the smaller fryers under 40 Litres.

At least they have fire codes on their side - a licensed (something we don't do) extinguisher engineer is obliged to install a K Class extinguisher only for cooking oils and is also obliged to red tag (condemn) any powder extinguisher being used for cooking oil cover (The Americans have the advantage that BC powder extinguishers are still widely used and thus cooking oil risks without a K class extinguisher have a 20lb BC Powder extinguisher, which is at least of some use unlike the UK which has long since been almost exclusively ABC, which being an acidic compound will not react with the oil to saponify it).

Parts of the latest NFPA 10 make our BS5306-3 & 8 look tame!

[Psuedonym]

What a brilliant idea - condemning kit for lack of common sense. At last an example of how our friends across the water do have some intelligence.   

[kurnal]

Plenty of blankets and co2's/powders/foams are still protecting (er.. fire blankets , protecting..??..) thier staff and wonderful cooking equipment (take a look sometime, you may not want to eat in your favourite restaurant/hotel afterwards though...such cleanliness, such condition of cooking equipment. (?) ) The majority of which haven't got a clue of how or what to use in the event of a fire.

Yes but BS5306- 8  clause B.5.2 does say that a fire blanket conforming to BS7499 (of course they mean BS7944) can be used as an alternative to two 75F units.

Now where can I buy a BS7944 blanket ?  Cant find them listed on most of the big suppliers sites?

[Psuedonym]

Oh don't you go worrying over that Kurnal, you should know you can have a restful night safe in the knowledge that the warming blankets are quite safe on fat fires. There's even a nice little picture on a particular breed which shows the Merry Chef putting a burning frying pan out with one. Of course the manufactures fail to mention that to use one on a burning fryer (which 9 out of 10 chefs I have actually asked and they assumed they were actually for fryers NOT frying pans !!!) would rearrange ones hands, arms and fingers, etc, burn through the blanket (assuming he could get anywhere near a raging fryer) and leave the Merry Chef screaming in absolute disbelief as he wondered why on Earth he was melting as the kitchen began to disappear in smoke, cos that lovely picture said he had to use the flipping blanket on the frye.................

ps Dear Mr Manufacturer, due you think you could have a chat with the end user of your next super idea, just to make sure the silly chap doesn't mistake your wonderful corporate idea for a practical product?

Just a thought.

[AnthonyB]

Yes but BS5306- 8  clause B.5.2 does say that a fire blanket conforming to BS7499 (of course they mean BS7944) can be used as an alternative to two 75F units.

Now where can I buy a BS7944 blanket ?  Cant find them listed on most of the big suppliers sites?

Ah the old mirage of the BS 6575-2 heavy duty fire blanket perpetuated via BS7499. I have over the years tried to track one down via all the manufacturers and never, ever , ever found one for sale, in manufacture or in service.

The only thing that is of the right consistency is a welding drape as made by a couple of the blanket manufacturers.

The fact that only Chubb (& a couple of non UTC importers ripping off Chubb labelling) bother to put the BS1869 limitations of the fire blanket on the label doesn't help with educating people.

[kurnal]

Have you seen the full length Ansul R102 demo video? Theres a pretty beefy fire blanket used on there (though it fails). But then it wouldn't be in the video if it had passed!

[Psuedonym]

Yes I know the one, I have run, ahem  , I have a few copies which I drop off to interested head chefs. (Those who show any interest in FP) I can't provide the full PPE kit though !!

[AnthonyB]

I've seen one Ansul video on the net, but not one comparing it with other means of tackling the fires.


With respect to the original post title 'fire rating tests' I don't know why we bother with ratings as I've yet to find a user, supplier or specifier in most places using them - most people are still using a variant of the old FPA & FOC scales based on area and capacity/type of extinguisher with no reference to rating despite two apparently identical extinguishers having totally different capabilities.

A super cheap far eastern 6l foam can be as low as 8A:113B whereas German uber-technology achieves 27A:183B on the same size.

It gets worse with Powder - different MAP content, particle size and flow rates give very different performances & ratings weight for weight, which in some situations can make a significant difference (just look at the Nu Swift video comparing their 4 kilo 90% MAP strike knob model versus a TG 6 kilo 70% MAP squeeze grip model)