Manu_2000 Posted July 4, 2019 Report Share Posted July 4, 2019 Why powder extinguishers are still sold? If AFFF is best... They told me that for general multirisk protection of shops offices or hotels powder is not recommended. What about for a home? Is it OK to install 2 x 6 litres AFFF and 1xCo2?can I have a 2kg powder in my car? Can I use foam spray on live electrical equipment up to 1000v at at least 1m? Is AFFF toxic or carcinogenic? Is true that ABC powder does not extinguish well class A fires? Are water based models better at this? Thanks Quote Link to comment Share on other sites More sharing options...
AnthonyB Posted July 4, 2019 Report Share Posted July 4, 2019 Powder still has it's place, some examples: - Spill & running fuel fires, where foam can struggle - Large fires requiring rapid knockdown - Low temperature areas - Class C fires where there are specialist staff to safely extinguish the flame and manage the resulting explosion risk - Multi risk areas where the secondary damage & personnel risks have been assessed as tolerable. Due to low cost it's still the most common multipurpose extinguisher for the home, although ABF Foam & Water Mist would also suit. Quantities of foam & CO2 extinguishers are based on risk, fire rating & travel distances - in some cases you might have a fire point of 2 x foam and 1 x CO2 Extinguishers that have passed the 35kV test are suitable for direct use on electrical fires up to 1000V - it's a peculiarly British thing that they avoid pointing this out and prefer to sell a CO2 as well. AFFF is an Irritant in concentrate (certain special blends are corrosive), but not a toxin or carcongenic. It's harmful to the aquatic environment and older blends were worse for the environment generally. Water (or water and wetting agent) is the best Class A medium as it cools and soaks, however powder can be effective if the right type: - BC Powder, usually an alkaline bicarbonate based medium is very limited on Class A as there is no cooling or smothering effect, just chemical inhibition, making it ineffective on anything but the smallest surface fire - ABC Powder, usually an acidic ammonium based medium has a greater effectiveness on Class A fires as it fluxes when heated and sticks to burning embers having a smothering effect as well as inhibition. There is still a risk of re-ignition in deep seated fires Quote Link to comment Share on other sites More sharing options...
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