Provision of extinguishers in student flats

[jakespop]

Multi occupied individual student flats( about 4-6 in each flat) in two and three storey building. Provision of fire blanket and foam extinguishers in communal Kitchen/Living areas. Comments made by contractor that foam should be replaced by DP/Carbon Dioxide.
Any comments?

[AnthonyB]

The default for kitchens these days is a blanket and 2 kilo ABC Powder (although in similar premises run by an NHS trust they had CO2 as they banned, quite rightly, powder across the whole trust).

In the kitchen the primary risks are the Class F chip pan for which a fire blanket could cope with and Class A with electrical supply for which you can choose Power, CO2 or 35kV passed liquid extinguisher if feeling brave.

For the other areas a 2 gallon water used to be king (increasingly now foam) but here, other than smoking your main initial fire will again be Class A with electrical risk.

Unless the Foams are condemned (not just be 5 years old and need and ES) I'd leave them be for now if they are a reputable model that has passed the 35kV test. Upon replacement I'd put in a 2 litre ABF foam extinguisher in which would deal with your A risk, any B risk, your F risk and be safe up to 1000V at 1 metre. Or be traditional and use ABC Powder.

If you went for CO2 you would still need Class A cover on top.

I think the engineer needs some sales!

[kurnal]

The underlying scare appears to be in respect of untrained students putting themselves in danger of electrocution by using water based extinguishers in close proximity to electrical equipment. I know this was a risk identified in BS5306, have any statistics ever been produced to indicate how many people have been harmed in this way?

Do they need to put extinguishers in each flat? Probably not. Get out shut the door stay out may be the alternative message. If they do provide them in flats its probably because they dont want to put them in the common areas - vandalism in a flat can be traced easily and persons held accountable. Vandalism in the common areas is a problem- theres no ownership. There are other ways around this however apart fom putting an extinguisher in each and every flat.

Other than that, as always  Anthony has it spot on.

[ahmedh]

Unless the Foams are condemned (not just be 5 years old and need and ES) I'd leave them be for now if they are a reputable model that has passed the 35kV test. Upon replacement I'd put in a 2 litre ABF foam extinguisher in which would deal with your A risk, any B risk, your F risk and be safe up to 1000V at 1 metre. Or be traditional and use ABC Powder.

If you went for CO2 you would still need Class A cover on top.

I think the engineer needs some sales!

Although the ABF is safe for electrical fires (some resellers state it as inadvertent contact), would you advocate its use for electrical (in a kitchen scenario) i.e no longer have a fire blanket or a specific CO2 extinguisher?

[AnthonyB]

Depends on which brand I installed and how brave I felt. The Jactone aerosol ABF is a solid stream discharge so definitely not electrically safe, but the EN3 stuff that is spray/mist is safer.

If our water spray, foam spray and wet chemical extinguishers were in mainland Europe most would be marked safe up to 1000V. Some UK manufacturers went as far as putting the electrical fire symbol on them.

On 240V unless in pooled agent that is in contact with the appliance you are safe. That's been demonstrated in the 1967 Fire Research Station study 'THE SHOCK HAZARD ASSOCIATED WITH THE EXTINCTION OF FIRES INVOLVING ELECTRICAL EQUIPMENT'

With wet chemical care is required as the nature of the solution is very conductive, the spray nature of the discharge is the safeguard. ABF foam is however a totally different compound.

I know people who have safely discharged a spray foam onto burning live 415V gear and survived - in mainland Europe there are live demonstrations of catalytic foam extinguishers being discharged directly onto transformers as part of the product tests.

I'm waffling as usual though....

Would I put a suitably tested ABF extinguisher alone as the only appliance in a domestic kitchen? Quite possibly, although if someone wanted to still put a CO2 in I would understand (commercial kitchens I advise Wet Chem, CO2 and blanket)

[kurnal]

On the JO course at Moreton in the 70s one exercise was to operate a main spray jet on a 30kV live electrical overhead cable. The point was to demonstrate the comparative risks of solid stream jets and sprays,  I wonder if they still do that?

[SamFIRT]

They were still doing it in the late 90's.

[ahmedh]

Depends on which brand I installed and how brave I felt. The Jactone aerosol ABF is a solid stream discharge so definitely not electrically safe, but the EN3 stuff that is spray/mist is safer.

If our water spray, foam spray and wet chemical extinguishers were in mainland Europe most would be marked safe up to 1000V. Some UK manufacturers went as far as putting the electrical fire symbol on them.

On 240V unless in pooled agent that is in contact with the appliance you are safe. That's been demonstrated in the 1967 Fire Research Station study 'THE SHOCK HAZARD ASSOCIATED WITH THE EXTINCTION OF FIRES INVOLVING ELECTRICAL EQUIPMENT'

With wet chemical care is required as the nature of the solution is very conductive, the spray nature of the discharge is the safeguard. ABF foam is however a totally different compound.

I know people who have safely discharged a spray foam onto burning live 415V gear and survived - in mainland Europe there are live demonstrations of catalytic foam extinguishers being discharged directly onto transformers as part of the product tests.

I'm waffling as usual though....

Would I put a suitably tested ABF extinguisher alone as the only appliance in a domestic kitchen? Quite possibly, although if someone wanted to still put a CO2 in I would understand (commercial kitchens I advise Wet Chem, CO2 and blanket)

I think we are prone to waffle; occupational hazard 

Ok, so ABF for domestic only, flats etc.

[jakespop]

If we move the present AFFF extinguishers out of the kitchens and site elsewhere in the flats and leave the blanket. Change foam to CO2 or Powder when due for renewal? That sounds a reasonable solution to me. Any adverse comments?

[AnthonyB]

Sounds fair enough, I'd go for 2 kilo Powder rather than CO2 given the occupancy, as Powders may be messy, but CO2 can be deadly (or at least dislocate your shoulder if the horn has been snapped off and it's used)

[TFEM]

Currently servicing 2kg powder units + fire blankets in student accomodation.....pretty sure you wouldn't notice the mess from a powder discharge!!!
 
John