Hi I wonder if you can help? I have riding stables and need to install fire extinguishers. I can't use powder near hay but I am worried about the freezing of water and foam fire extinguishers, especially now in winter. What temperature ratings should the extinguisher have? Are foam and water suitable at all?

Thanks

Jan

Yes you can use water and/or foam if a suitable anti-freeze is added but only use that which is recommended by the manufacturer. Ethylene glycol and propelled glycol depress water’s freezing point, but also thicken at very low temperatures, eventually clogging extinguisher nozzles. Newer freeze-point depressor solutions use salts, which will not thicken as the extinguisher discharges. Class A or B extinguishers and other liquid-based extinguishers must contain these compounds if they are to be stored where temperatures fall below freezing. On the extinguisher the the minimum and maximum temperature range should be displayed (in accorance with BS EN 3) and can be as low as -20⁰.

You might be interested in the Fireworld extinguishers which are suitable for outdoor use, corrosion free, designed for self-maintenance and the foam with antifreeze version goes down to -10⁰

Harry

I am interested in what percentage of antifreeze is allowable before it has an effect on the ratings and use of the extinguishers , does it affect the ratings in any way?

It depends on manufacturer - usually antifreeze has the most effect on a Class B rating and in some cases reduces a 6 litre foam down to 113B, but you need to check this from brand to brand. Note that many manufacturers don't carry out rating tests on units with antifreeze (not a big enough demand to satisfy the costs of testing) so you have no guarantee of efficacy.