Minimum number

[Luke]

Hi. I’m opening up a shop this month and am keen to adhere to all of the legislation. Currently looking at the P-50 extinguishers as this seems the best option for me. 
 

The shop is very small, approximately 40-60m2. No specific risks, so looking at the foam version. One entrance and one exit in the small back room (no bigger than 8m2).

I've read that a minimum of 2 extinguishers are needed, but if small enough then only one is required. But can’t find anything concrete on what size is classed as small. 
 

The previous occupier only had a 9L water extinguisher which is still in place, but will be removed as it’s not been serviced for a very long time so will likely need replacing. Many of the other units are also the same size and they only seem to have small car sized foam or powder extinguishers which I also gather wouldn’t meet the requirements. 

[Harry]

Hi Luke

The British Standards are suggesting a minimum of 2 extinguishers, however, BS standards are just recommendations. You have to use a dose of common sense and such a small space would be well covered with the suggested foam extinguisher. That is if you are a standard shop or office. If you store flammable liquid etc you would need professional advice.

An extinguisher needs to be big enough to extinguish a small fire reliably, so the P50 foam in the 6ltr version should be suitable. 

Harry

[AnthonyB]

Size of an extinguisher has not been a factor in specifying extinguishers for nearly 50 years. The fire rating of the extinguisher (the biggest fire a trained operator can put out with the extinguisher)

The minimum recommended rating is 26A, made up using a minimum of two extinguishers (e.g. 2 x 13A rated units), however in a small premises a single 13A unit may in reality suffice.

Your old 9 litre water will have a 13A (or 21A) rating - but so does a 2litre Triclass P50 with the added benefit of a 55B rating for flammable liquid fires and safe to use on fires where an electrical supply of up to 1000V is present.

On a few office sites now I've been able to replace a fire point of a 6 litre water and 2kg CO2 with a single 2 litre P50 as the ratings are the same.

[Hayfever]

I note that the 2litre Triclass P50s (as mentioned above) have been discontinued and the former 13A and 55B is now replaced by a 2litre water mist with an 8A, 5F rating

That's not much of an alternative is it as you now need to buy 2 units to get the same rating???

Do I take it the change is for environmental protection reasons? (The effects of foam to the environment?)

[AnthonyB]

On 30/08/2024 at 13:42, Hayfever said:

I note that the 2litre Triclass P50s (as mentioned above) have been discontinued and the former 13A and 55B is now replaced by a 2litre water mist with an 8A, 5F rating

That's not much of an alternative is it as you now need to buy 2 units to get the same rating???

Do I take it the change is for environmental protection reasons? (The effects of foam to the environment?)

Yes - Fluorine free foams are available, but they require a different method of delivery using a large aspirating nozzle instead of a small non aspirating spray nozzle which would require extensive redesign of the 2L valve to fit, plus it's not clear if it would still achieve the high ratings.

6 & 9L P50 foams still exist but not a 2L unless sufficient demand to remodel the design to accommodate F3 foam exists.

I feel your pain - I used the 2L a lot in building change overs as it was very costs effective.