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Comment by atarian | Hacker News Reader

I bought a fire extinguisher recently but I’ve never used one. I have a faint idea of how it works and what kind of result I’d get based on what I’ve seen on TV. But if a serious fire ever breaks out I don’t even know if I’d even remember to grab and use it.

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In a "serious" fire you should ignore the fire extinguisher get everyone out of the building.

Fire extinguishers are for small fires! If a little oil in your frying pan catches on fire and you don't have a lid readily available to smother it, use a fire extinguisher. But if your smoke alarm wakes you up and you discover your whole kitchen on fire, get out. The fire extinguisher will not help in that situation, and it may cause you to waste time. (Tip: If and only if the fire extinguisher is easily available, carry it with you as you exit. You might need it to use it clear a path to get out.)

Check the class of the fire extinguisher and if it is suited for liquid fires before using it on a oil fire.

A fire extinguisher is to clear a safe path to the exit if the fire blocks it. never put them by the exit door as I see so many people do (in their garrage)

they can also be used on small fires but only if there is a safe escape route. (This is probably the most common use but not the primary use)

99% of the benefit of putting the extinguisher by the exit door is that it helps draw panicking people to the exit door. Which gives them another saving throw against Heroic Idiocy, at +4 - "Should I grab this totally unfamiliar little fire extinguisher and carry it back toward the big scary fire, to do something I've never even tried doing? Or should I just run out the handy exit door that I'm right next to?"

> If a little oil in your frying pan catches on fire and you don't have a lid readily available to smother it, use a fire extinguisher.

We were told to just toss a large cloth on the fire in such cases.

That's right, the best is to have a watered dishcloth that will suffocate the fire, hence stopping it. The fire extinguisher may be a bad idea because the pressure will spread burning oil around across the kitchen and the water is definitively the worse idea because it will counterintuitively make a bigger flame and also spread burning oil.

Watered dishcloth? Water is the absolute last thing you want near very hot oil, never mind burning oil.

You're right, the best is a metal lid.

That works, but be sure to use a wool or cotton cloth.

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The proper method to deal with an oil fire: turn off the heat and smother the fire with a metal lid, metal baking sheet, or wool/cotton cloth. Do not use a fire blanket made of polyester or nylon; it will melt and burn producing toxic smoke. Do not use flour or any other flammable/explosive powder. Do not use water, as the liquid water will get into the oil and expand 1600 times its original size as it turns to steam; this rapid expansion will fling burning oil everywhere. If you do use an extinguisher, be careful not to spread the burning oil.

For small NON-OIL, non-electrical fires, smothering with a wet non-synthetic cloth is the best way to stop the fire.

When it happened here, I instinctively threw the flaming pan out the adjacent open door into the yard. We ate something else that day.

If you have an old one that you want to get rid of, it's a good idea to set up a controlled fire and try out your extinguisher on it. That way you can get some experience.

Really though, it mostly is just pull pin -> aim low (at the base and source of the fire) -> squeeze until extinguished. Sweep the nozzle from side to side to get proper coverage.

They're intended to be used by anyone with no training, so there's not much to go wrong (assuming you haven't bought the wrong type and use it on an oil fire, although most of the ones I see for sale for consumers are the powder kind, which work on anything. The water ones are the worst, and I've never seen one).

and it needs to be remembered not to hold the nozzle - aim with the whole extinguisher

nozzle gets veeery cold as gas expands, so you can get frost burns

I've seen a video of someone pointing an extinguisher the wrong way and blasting themself in the face! In their defense, they were under some stress.

As someone who has found themselves in a situation out in the wild with a fire and a fire extinguisher (neither of which were mine), with no direct extinguisher experience, you can take some solace in that they work very easily. They're not some wild hose that going to send you around the room. There's very little force. And you can simply fire it in bursts. It takes no time to get a feel for it and use it with precision.

If you find yourself with a fire and an extinguisher, do not hesitate to pull the pin, and go to it. You'll figure it out. In the end, you can't really make the situation worse.

If you're in the U.S., you might check if your local fire department has a CERT[0] training course. (I did it many years ago in San Francisco; they call it NERT for some reason.)

It'll give you a chance to practice putting out an actual fire, refresh first aid skills, learn the incident command system, learn basic search and rescue, and other preparedness skills to help yourself, your family, and neighbors in an emergency (in that order).

[0]: https://www.fema.gov/emergency-managers/individuals-communit...

In fire school we learned PASS -- pin, aim, squeeze, sweep. Even well-trained professionals need simple mnemonic devices.

Also, we never used a seatbelt ripper -- they don't work. All first responders carrier trauma shears. Those do work and have multiple purposes.

If you are looking to practice, the MythBusters said a fire extinguisher was an excellent way to quickly cool a case of beer. So, you can make it a $30 party trick and a teaching moment.

They were using carbon dioxide fire extinguishers, which are expensive (a couple hundred dollars, see [1] ) and not common in homes.

[1] https://fireextinguisherdepot.com/carbon-dioxide-fire-exting...

So, a $200 party trick when you are really committed to the bit.

Water extinguishers are almost completely useless.

I once had a go at putting out a fire in a waste paper bin with a water extinguisher, as part of a fire safety course. The burning paper just floated on the water as the bin filled up.

CO2 extinguishers are more effective. But I believe you have to be careful where you hold it or your skin may freeze onto it.

Get a fire blanket for your kitchen.

The time you want water is when something that water can soak into is on fire. Sofas, curtains, bedding, bookshelves, carpets, filing cabinets full of paper, etc.

The water soaks in and prevents the fire re-igniting. 30 years ago, workplaces contained a lot more filing cabinets and bookshelves, and smoking was more common.

CO2 is non-conductive, and less messy. It's also great at flowing around things, making it good for spraying through vents into electrical cabinets and car engines. Downside is the CO2 dissipates within a few seconds, so if the material is prone to re-igniting it's not such a good choice.

Dry powder is in between - the powder stays around, but doesn't soak in. It's a good choice if you're only going to get one extinguisher.

Water extinguishers are incredibly useful for putting out small incidental fires that can result from hot work without making a big mess. The kind of stuff you'd just move outside or let burn out rather than discharge a powder extinguisher over.

Nobody is whipping out a dry-chem extinguisher because the leaves under the workbench caught on fire from welding sparks.

Water mist fire extinguishers are nice. They are much more able to cool lightweight, flammable objects, and pose less risk of causing electrical arcs.

A couple years ago somebody parked a stolen car in front of our building, stuffed a rag in the fuel filler, and lit it. I must have pulled up just a couple minutes after they had left. Grabbed the fire extinguisher I kept under the seat and put it out. I had that extinguisher around for about 5 years. You never know when you'll need it.

When I was young we'd find expired fire extinguishers and go blast each other with em. Very easy to use. Good times. Hope they're not toxic...

My son picked up and used one effectively having about the same level of experience you do (none, but he knew the basic idea and had read the label). Can’t remember if he was 7 or 8 at the time, but either way I’m pretty sure you’ll be ok.

I mean, still doesn’t hurt to get more familiar, but…

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