foam for grease or fat fryer fires?

[abdulcroft]

can foam be used on a grease or fat fryer fire??

I mean if a class k extinguisher was not availble???

[SgtScott31]

Yes, foam will work

[nmfire]

A plain old ABC or BC dry power extinguiser will work as well. You don't need class K.

[abdulcroft]

caf systems

do you think a cafs system could extinguish a grease fire or fat fryer?

ps. only pressurized to 100 psi

[abdulcroft]

do you think a cafs system could extinguish a grease fire or fat fryer?

Yes, foam will work well ????will it work at 100 psi from a cafs system???

[DeputyChiefGonzo]

In Massachusetts, any deep fat frying system has to be covered by a kitchen suppression system, using a wet chemical extinguishing system along with Type K extinguishers as backup.

Can you use dry chem? Sure, but it does make more of a mess.

Can you use foam? Yes, as long as it is rated for flammble and combustible liquids.

[LaFireEducator]

As the good captain said, Dry Powder will work, and it is extremly effective, but it makes a hell of a mess and is a real headache for the restraunt owners to get cleaned up. The main advantage to either a AFFF foam extingusher or Class K extingusher is the fact that there is a lot less cleanup after we leave.

In fact, a CO2 extingusher, which is also rated for Class B fires, in the hands of an experienced firefighter can also be very effective on smaller grease and vat fires, and doesn't leave the mess that a powder extingusher will.

[nmfire]

And if this is refering to your home kitchen... where most of us don't have hood supression systems, never under estimate the power of the lid or some baking soda.

ALWAYS use care when spraying or dumping ANYTHING on a grease or liquid fire. Direct high pressure spray will just spash the burning liquid all over the place and make it worse.

[Steamer]

If the oil has heated to the point of auto-ignition, the foam may break down very quickly from the heat, and require reapplication until the oil cools down. You better stick around for awhile to make sure it doesn't reignite, or better yet, put a lid on it to prevent reflash.

As for the dry powder, a lot depends on what is being used as the oil. The powder will eventually sink in vegetable oil due to emulsification, but will continue to stay on the surface on animal fats. That's why the K-extinguishers and UL 300 hood systems came into play. Vegetable oil fires were reigniting because the powder would sink allowing the overheated oil to be exposed to the air and reflashing. The UL 300 liquid has a specific gravity less than both the veggie oil and the animal fats, so it can't sink. Because of that, it maintains a film on the surface of the oil until it cools down.

With that being said, regardless of the extinguishing medium, I'd "put a lid on it" to keep it from reflashing. It's not going to happen with the K extinguisher, but if you do it all the time, you're safe.

Kinda like wearing a belt and suspenders at the same time, I guess.

[abdulcroft]

abc dry chem and foam

i thought the idea with any agent is to apply it gently to the surface of the

liquid?


and is abc good for class k fires?

i mean according to the fire code it says it can reignite like to hear any idea you might have or on the possibilty of reigniton for abc


thanx

[SFD9203]

The main difference between class K and an ABC extinguisher is that class K is an alkaline substance which produces a soapy foam when it is applied to burning cooking oil and animal fats (saponification). The foam interrupts the burning process and also produces steam which cools the fuel. ABC on the other hand is acidic in nature and doesn't produce the saponification effect of class K. Therefore, you need to be sure the material has cooled enough to prevent re-ignition. Hope this helps.

[abdulcroft]

abc

The main difference between class K and an ABC extinguisher is that class K is an alkaline substance which produces a soapy foam when it is applied to burning cooking oil and animal fats (saponification). The foam interrupts the burning process and also produces steam which cools the fuel. ABC on the other hand is acidic in nature and doesn't produce the saponification effect of class K. Therefore, you need to be sure the material has cooled enough to prevent re-ignition. Hope this helps.

i mean i think i herd when 20lbs of abc is used on fat fryer it generally does not re ignite does this sound right. it seem to me this is right but i guess its easier to reignite than baking soda ?

[SFD9203]

Personally, I've been to several fires in fast food restaurants where ABC or CO2 was used and the fire was handled effectively. I think success depends mainly on the size of the equipment and how much oil is being used. As mentioned before, the biggest problem with ABC is the clean-up. A 20 lb ABC will produce a huge mess that will shut down most restaurants for 24 hrs or longer between actual cleaning and having the health dept come in and do a through inspection. From what I've read, baking soda would seem to be a better choice than ABC but I can't say for sure from practical experience.

[Dalmatian190]

Let's think about the physics of the situation.

Facts we know:

1) Oil floats on water.

2) Cooking oil is generally heated to 375* F for cooking.

It will flash around 600* F.

3) Water converts to steam at 212* F.

Let's say you have a fry-o-later with 5 gallons of oil in it -- I'm picking that since it's been nearly two decades since I last worked in a restaurant, and I found a source that lists that it takes:

14 BTUs to raise the temperature of 5 gallons of generic vegetable oil 1* F.

So you take your 2.5 gallon pressurized water can with foam in it.

Heck, let's assume you where able to dump all of it on the fry-o-later (you won't for a reason to be made clear in a moment).

Bring 1 gallon of water from 70* F to 212* F will take 142 BTUs.

Converting that gallon at 212 to steam will take an additional 970 BTUs.

Given we have 2.5 gallons of water, it'll suck 2780 BTUs out of the oil.

Of course, some schmuck had let it get to 600 degrees in order to flash (somebody put a match to it...) -- and vegetable oils can get up around 675* F to auto ignite.

Take the 2780 BTUs you PWC can theoretically absorb, divided that by the 14 BTUs / 5 gallon veggie oil / degree, you get that the extinguisher can drop the temp of that oil by 198.5 as the maximum possible, and your mileage undoubtly will be worse in real life.

600 - 198.5 = Still really damn hot and it's gonna burn any exposed skin, eyeballs, etc.

Wait? Why would it burn your skin?

Because oil floats on water, and water is being turned to steam -- what doesn't instantly vaporize goes underneath the oil, suddenly converts to steam, and you spray hot if not still burning oil all over the place, including you. You did put on full PPE including SCBA before pulling the trigger on the extinguisher???

And I'm not going to trust that 6" faceshield on the helmet against splashing oil -- even if I was wearing googles to protect my eyes, I'd rather not end up looking Edgar James Olmos quite yet.

It gets even more interesting if the oil that was sprayed was still above the auto-ignition temperature and starts burning everywhere.

Of course, if you're going in with a handline we're talking about a different situation (slightly) as presumably you're in full PPE including air pack, you're hitting the fire from further away (remember you can bounce the stream off ceilings or off equipment to get around corners), and you're flowing enough water to rapidly cool off the oil -- so their maybe an intial spray but any oil or fire will be overcome by the flow of the line.

So...

If I only had hand extinguishers...at most I'd use the 2.5 gallon judiciously and from a distance to keep spreading fire in check until we either have to abandon the position, get a dry-chem or Class K extinguisher up, or get a crew with a handline there.

The best case you're looking at is the water/foam from the extinguisher is at a low enough rate that it all rapidly converts to steam on the surface of oil spraying small drops of hot oil and water all over, but none drops underneath the surface to cause major blowouts. Then the cooled surface oil sinks and 600* F oil from down below rises to the surface. Even worse is if the container hit auto-ignition temperature, in which case fresh oil at 675* F rises to the surface now devoid of foam which cooked off, has oxygen, has enough heat, and ignites itself.

DryChem doesn't cool the oil as quickly, so you don't get the circulation of fresh, hot oil to the surface las quickly as water will.

Class K's liquid component doesn't turn to steam at these temps, so it's not splashing and splattering.

Foam extinguishers are effective on gasoline and diesel since presumably those fuels haven't been heated above the steam point of water -- gasoline will flash around -50*F and diesel around 125*F.

Municipal services seldom encounter a situation of fuels heated above the steam temperatur of water. The foam smothers the fire, and whatever water sinks into the fuel remains relatively benign.

Now the Industrial boys do worry about this -- where you have hot fuels due to the refining processes, or a tank full of fuel that's been heated by adjacent fires. You can google "Tank Fire Boilover" -- that's a bad thing when it happens.

It's all in the physics of the situation

Matt

[nmfire]

i mean i think i herd when 20lbs of abc is used on fat fryer it generally does not re ignite does this sound right. it seem to me this is right but i guess its easier to reignite than baking soda ?

If you use an entire 20lb extinguisher to extinguish a kitchen grease fire, something is wrong. We're talking about a kitchen, not an entire tanker truck.

You are making this way too complicated and looking way to deeplying into it. Don't worry about little things you've heard and thought. Listen to what people here are telling you.

1. Class K agents work best because of their ability to stay on the surface of the liquid and prevent re-ignition and make less of a mess.

2. Dry chemcial power (ABC or BC) will extinguish the fire just fine. However, they do very little to prevent re-igntion since the power will sink in the liquid that is still hot. It will also make a giant mess and you'll be eating it for a week.

3. CO2 extinguishers will extinguish the fire just fine as well. However, like with any fire, using a CO2 extinguisher requires getting a little closer than you might like. It also will not prevent re-ignition like a class K entinguisher.

4. Taking a hose line in with any kind of foam will work too. However it will probably destroy more than the fire ever would have.