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Comment by kayodelycaon | Hacker News Reader

In the US, electrical fires are class C fires. Many fire extinguishers available are ABC extinguishers, which means they can deal with class A (material), B (liquid), and C (electrical) fires. Extinguishers for class D (metal) and class K (high temperature grease/cooking oil) are not common in households.

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Isn't this a chemical fire not an electrical one since it's a chemical reaction in the battery that is causing the fire? The fact that normally that chemical reaction makes electricity rather than violent heat seems moot. The battery also has the oxidizer in it so an extinguisher that tries to block oxygen won't work at all.

https://resources.impactfireservices.com/how-do-you-put-out-... You may be right.

However, it doesn't really matter. Buy an ABC extinguisher for your kitchen and for your garage, and just use it if needed. You don't need to overthink this.

Yes and no, the exothermic reaction ignites the electrolyte solvent, usually a blend of organic carbonates (depending on the type of battery). So it's almost a liquid fire, a chemical fire and an electrical fire all in one. It doesnt have an oxidizer, but the chemicals do contain oxygen. But ultimately there are 3 ingredients needed for a fire, fuel, oxygen and heat. An extinguisher targets two of these by cooling it down and limiting oxygen.

The exothermic reaction will also slow down when cooled which will further help contain the problem

Whoever FireRescue1.com is says that a class B fire extinguisher is good for a cooking oil fire, but that first (presumably more usefully) you should cover it and smother it in salt.

https://www.firerescue1.com/community/articles/how-to-put-ou...

Very small cooking oil fires, yes. :)

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