Are P50 Extinguishers Safe on Electrical Fires?

[Messy]

Sorry - Its P50 extinguishers again!

Britannia are marketing P50s as the only extinguisher required. They say it's possible to lose the traditional 2 x extinguisher approach and use a single P50 as it is safe on electricals (as well as class A and B). See video below

The claim appears to place P50s in the water mist extinguisher area, as they seem to have passed the same dielectric testing. However, I havent heard of anyone binning CO2s and just going with water spray

I thought dielectric 'approval' was in case of accidental discharge onto electrics, and not as the primary means of firefighting on live electrics

So would you replace your CO2 and water/foam with a single P50? If not, why not?



https://www.youtube.com/watch?v=kXBNfgWRfAA&t=50s

[AnthonyB]

Yes they are. Just like every water based spray extinguisher in Mainland Europe is and has been for decades. Just like they even were in Britain when first introduced until it was seen to be not the done thing (nothing to do with any actual incident)

The extinguishers are marked as safe for direct use on electrical fires up to 1000V in accordance with EN3, the European Manufacturing Standard (the pure Euro version, not the UK version) for fire extinguishers and the manufacturer, Britannia Fire, is fully prepared to guarantee their product safety.
 
Whilst BS5306-8 does suggest that premises should install CO2 extinguishers, it is only guidance and is written with heavy input from the extinguisher trade and many clauses are not evidence based. Most mainland European extinguisher provision codes and implementations of EN3 support the use of di-electrically tested 'wet' extinguishers for direct use on low voltages (i.e. under 1000V) and there are no known cases of electrocution from approved extinguishers - historically electrocution cases date back decades to the use of soda-acid extinguishers (discharging powerful electrolyte solutions) and more primitive electrical installations without circuit safeguards.
 
Many large concerns have switched to a single extinguisher type (Britannia Triclass, the foam spray model, either in steel or Kevlar bodies) in some or all of their premises including: MITIE, Kier, Legal&General, CofE, Catholic Church of UK, ShopDirect, Integral, Phillips 66, Mid Sussex District Council, Courtney Buses, Guys & St Thomas NHS, Bournemouth University, Bowmer & Kirkland, Harrow College, Saga, Empire Cinemas, Anglian Water, University of Brighton to name but a few and do not have CO2 extinguishers on site. Other sites such as some of the University of Sussex, Syngenta, Mattersey Hall and several historic halls have done similar, but with water spray or water mist
 
Four Fire & Rescue Services via their trading arms are selling P50 triclass extinguishers as replacements for needing both water/foam & CO2 in commercial premises.
 
Faraday Laboratories and the old Joint Fire Research Organisation (a Joint Government & Insurance Scientific Body) have carried out tests showing the safety of water based sprays, particularly under 1000V, at the normal safe user distance. British Rail in the late 1980's replaced Halon (used for electrical equipment fires) and Water extinguishers with Foam Spray extinguishers due to their safety in use.

The trade seem to not like anything that limits quantities hence why high performance high rated wet extinguishers aren't as commonly installed as in Europe and why electrically safe units are not sold as such and let's leave the P50 as a separate issue....

[Owain]

Yes they are. Just like every water based spray extinguisher in Mainland Europe is and has been for decades. Just like they even were in Britain when first introduced until it was seen to be not the done thing (nothing to do with any actual incident)... and there are no known cases of electrocution from approved extinguishers - historically electrocution cases date back decades to the use of soda-acid extinguishers (discharging powerful electrolyte solutions) and more primitive electrical installations without circuit safeguards.

I suppose there may still be a case for CO2 in electrical switchrooms and similar where mains intakes not protected by MCB or RCD are present, and where water would need to be dried out before reenergising the undamaged parts of the installation?

[AnthonyB]

There is indeed still a case for CO2. In one office building where all the office floors had 3 litre electrically rated water and the basement car park similarly rated 6 litre Triclass I still put in 2 x 2kg CO2 as there were two rooms with installations over 1000V. It still allowed simplified training as in case of fire you just picked up the nearest extinguisher, no worries about checking two different ones at a fire point.

I've had a customer successfully use a water mist on a live 415v industrial dryer fire after a CO2 had no impact, no issues reported other than it was very effective!

[lyledunn]

Anthony,
This is very interesting for me. I look after the licensing requirements of more than 100 premises in NI. Currently, it is required that CO2 provision is made where entertainment is provided. It would simplify matters greatly if only one extinguisher type was required.

[nearlythere]

Anthony,
This is very interesting for me. I look after the licensing requirements of more than 100 premises in NI. Currently, it is required that CO2 provision is made where entertainment is provided. It would simplify matters greatly if only one extinguisher type was required.

I can understand why they would specifically require a Co2 Lyle. Because they don't know any better.

[lyledunn]

I know NT but then again they are often very well-educated folk with a fairly broad remit. I can have a sneaky one up on them by having you guys as an Aladdin's Cave of fire safety gems.

[gor810]

I have come across a similar situation in Scotland recently where I visited a newly refurbished premises and they had been provided with water type extinguishers safe for use on electrical fires. They did not state live electrical fires mind you.

As a qualified extinguisher engineer and an individual who undertakes fire risk assessments of premises, it is my opinion that the reliance upon such multi functional extinguishers is flawed.

Portable firefighting equipment in the wrong hands by an untrained operator can be hazardous. The distance of 1 metre has been mentioned. Do we all carry a measuring tape in an emergency? What if we tackle the burning toast in the live electrical toaster from 0.8 metres?

Portable firefighting equipment is recommended to be serviced annually and if not serviced by the installing engineer/company who are familiar with or installed the equipment, it may not be serviced as required. On the 5 yearly discharge test is it tap water that the engineer will refill the extinguisher with or is it di-ionised water?

Having just completed a fire risk assessment on a premises provided with extinguishers with a dielectric rating, I have, as an assessor, recommended that consideration be given to the provision of carbon dioxide extinguishers in addition to the water extinguishers provided.

This recommendation is not given on a selling or profit basis but through a genuine concern for the safety of the individual who may decide to tackle a fire with an extinguisher and through no fault of their own be injured or worse.

[nearlythere]

I have come across a similar situation in Scotland recently where I visited a newly refurbished premises and they had been provided with water type extinguishers safe for use on electrical fires. They did not state live electrical fires mind you.

As a qualified extinguisher engineer and an individual who undertakes fire risk assessments of premises, it is my opinion that the reliance upon such multi functional extinguishers is flawed.

Portable firefighting equipment in the wrong hands by an untrained operator can be hazardous. The distance of 1 metre has been mentioned. Do we all carry a measuring tape in an emergency? What if we tackle the burning toast in the live electrical toaster from 0.8 metres?

Portable firefighting equipment is recommended to be serviced annually and if not serviced by the installing engineer/company who are familiar with or installed the equipment, it may not be serviced as required. On the 5 yearly discharge test is it tap water that the engineer will refill the extinguisher with or is it di-ionised water?

Having just completed a fire risk assessment on a premises provided with extinguishers with a dielectric rating, I have, as an assessor, recommended that consideration be given to the provision of carbon dioxide extinguishers in addition to the water extinguishers provided.

This recommendation is not given on a selling or profit basis but through a genuine concern for the safety of the individual who may decide to tackle a fire with an extinguisher and through no fault of their own be injured or worse.

So water mist is not safe for use on fires involving electricity? Should this be referred to the manufacturer and Trading Standards?

[Messy]

Many thanks for the replies and especially to AnthonyB for the detailed info