If you want french fries and gravey, squonnk, come to Texas. This is the South, honey. Ya'll know we put gravy on everything. Usually after we fry it first. Fried pickles....yummmm.

As for barn fires, yes, they do happen. It has to do with gasses building up from the hay and igniting. Sometimes sunlight on a hot day is sufficient to get the gasses from the hay to hit their flash point.

As for the compost piles, I think you'd need a large one to get it to happen. Just as the barn/hay fires don't happen with a bale or two, I doubt that the compost fires would happen with a small heap.

M.

The Alberta (Canada) Agricultural site says that compost fires are caused by:

biological activity
relatively dry materials
dry pocket
large well insulated piles
limited air flow
time for temperature to build up

My thoughts:
Biological activity may conceivably get the pile up to 200F, but it takes 451F to get dry paper to dry.

If you've got a dry compost pile, it isn't likely to really heat up, is it?

Limited air flow would REDUCE the composting action, and how would LACK of oxygen feed a fire???

I'm waiting for someone to spill the beans and say something like "Yeah, we had a compost fire, sure. And it burnt up that bucket of gasoline that I was resting my cigarette on, too."

Sue

It would be interesting to find an old barn ready for demolition and have leaders in the field of chemistry physics and micro biology fill the barn to the rafters with green compost. The objective would be to burn the barn down. The only stipulation would be that only organic material normally used to make compost could be used.


John

I'd be happy just to have someone conclusivly show that a home-sized compost pile has combusted without some outside ignition or, on the otherhand, to just accept the whole concept as the myth it seems to be.

Wayne

In the summer my compost gets hot. When I flip it some areas look charred, as if burned. I tell myself that it's mold, but sometimes I wonder. It sure looks as if it's been burned.

I can believe the barn burning story. But I don't worry about it in my little compost bins.

Karen

"For one to state that spontaneous combustion does not happen because they have not seen it is similar to stating that the lights you use cannot light because you have not seen electricity."

NOW I know my gas lamp is electric!And that compost emits photons!
I'll report back after I hook up some romex to the compost pile.

I was a paid on call firefighter for 25 years (sometimes called a "volunteer") and during that time I went on 6 barn fires caused by improperly cured hay spontaneously combusting in the loft, that happens. During that time I also went on 5 fires involving compost piles that spontaneously combusted, that also happens. I have also spent hours on a very cold January day extinguishing a pile of bark that spontaneously combusted. Because that kind of thing happens is why the Occupational Safety and Health Administration and the National Fire Protection Association have published standards for storing organic materials on business premises. Piles of organic material can spontaneously ingite, catch fire.
Karen, what you saw in your compost pile is known as "flash" (a leaf that still looks like a leaf but is burned looking) and it is the result of a very quick fire that self extinguished, something that also happens but also has doubters.

I'd still just be happy with an empirical demonstration of how bacteria could develop at temperatures above the level which they can survive. Flash points and sterilization temps are kind of mutually exclusive concepts.

Im more inclined to entertain the notion of barn fires simply because the air temp in a barn loft with a tin roof and machines or animals on the lower level can get quite high and combined with the temp of decomposing hay then maybe we've got something closer to a flash point. But a compost pile just minding its own business?? Im from Missouri, show me the data.

I have difficulty with stories of farmers storing improperly cured hay causing so many fires. A) Only a moron would store wet hay in a loft of a barn. Sorry for being blunt. B) A lot of kids hide/play up in the lofts of barns and experiment with smoking/matches/magnifying glasses. Been there, done that. C) Rats and mice live in barns and have chewed through electrical wiring. D) etc etc... I can imagine the conversation with the insurance adjuster. "Honest Sir, I don't know how that barn caught on fire, I must have had the hay too wet when I put it up there." Did I mention that I am a skeptic.

Now to the compost, mulch and lumber piles. Once again, too many potential ignition sources to say all these stories of fires are "spontaneous". I suspect that these fires are caused by people who are too ashamed to admit they accidentally (or otherwise) lit them.

Sorry kimmsr, I don't buy it. How many barn fire calls did you go on that there was a determined cause and what were those causes? How many compost/organic fire calls did you go on that there was a determined cause and what were those causes?

Lloyd

What reason, exactly, would anybody have to doubt reports of hay combusting in barns? Believing it happens is not like believing in Hellfire. As for compost piles catching fire, I just realized what you're up to, Lloyd. You are trawling for tips on how to make your compost piles combust. :)

And maybe people who try to get their piles to reach 150-160-170F are closet arsonists? Because heat like that certainly doesn't make good compost.

The only reason hay combustion is brought up is because its been pointed to as an example of how compost might also self-ignite but I suspect that the examples of hay burning have at least as much to do with the air temperature the hay is stored in as it does the internal heat of the hay. Im saying absent that external energy source it aint gonna happen

The reason hay fires ignite is because of the very large volume of hay that is stacked in the barn, doesn't allow the heat from decomposition to dissipated... heat loss is unable to balance heat generation. And has nothing to do with outside ignition sources. I've seen it with my own eyes.

It takes very large volumes to impair the heat loss.

What reason, exactly, would anybody have to doubt reports of hay combusting in barns?

I don't doubt it does happen, I doubt it happens as often as some people think or say it happens. I doubt that they are mostly "spontaneous". Farmers ain't that dumb. I also doubt 50% of the news I read, and 75% of the stuff on forums. (higher percentages from some posters)

I prefer logic over emotion. I believe there can be many sides to each story and one explanation does not always fit all situations. I believe absolutists are absolutely goofy. :) When I hear hoof beats, I try to think horses not zebras.

While it might be cool to see an average pile of compost spontaneously combust, I ain't gonna hold my breath.

Lloyd

I was teasing you about that part Lloyd.

Hi Paul, ya I think I caught that drift but in re-reading my posts I can see where some might think that I totally discount the possibility of a spontaneous ignition. Your post just gave me an opportunity for clarification. (and to throw in the absolutist comment, I get a kick out of that)

HRC

Plus you might need your breath in case one of your piles does combust.

Why would a farmer put up some hay that is too green???

I guess you just have to have been in farming to understand that one. Think...a rain is coming and it hurries things up a bit. The nights dew makes thing wet anew and we need to get putting up the hay as there is a 6:00 o'clock meeting and rain may come in tonight.....and so on. It just happens. Also parts of a field may be perfectly dry renough and some areas of heavier growth may be not quite as dry.

Sorry Wayne, who asked that? I went back through the thread but I couldn't find that question (but I might have missed it). Trying to get the context of the question, where did you get it from?

Lloyd

Well okay.....

When you're wrong you're wrong, or Im wrong in this case.

http://extension.missouri.edu/explore/agguides/crops/g04575.htm

This is a pretty good explanation and I'd suppose that the basic concept would hold for compost as well. It isn't the bacterial action that ignites. As noted at several points in the discussion anything much over 175 is going to kill the bacteria. After that point "heat producing chemical reactions" can take over and get the temps well up over 400 degrees which can obviously start a fire if other conditions are favorable such as temperature and moisture content of the cut hay itself which would be somewhat different than hay thats gotten wet in the field.

So there it is. Humble pie on me. I'd be curious to know more about those heat producing chemical reactions.

I highly doubt a normal sized home compost pile can combust. I have no doubt that large commercial, agricultural piles can. just because you havn't seen it, doesn't mean it's impossible.

Kimmsr: Interesting comment about "flash" occurance. It does sometimes look as though that has happened, but I never thought it could. I guess I thought if a fire started, the whole thing would combust, not just a small spot or layer. I really never heard of that before. (Not saying it can't happen, only that I'd never heard of it, didn't think it could).

And about the fires you witnessed. I can easily understand a barn going up in flames. But how about the compost piles and mulch piles? How big were they? As big as a house? A volkswagon?

Karen

LLyod,
You've said you don't believe spontanous combustion is possible. You've said you don't believe the media or the internet. Every link or story that has been posted, you have said you don't believe. Gov't agancies have regulations about storing organics to prevent fires, and you refuse to accept it's possible. No matter what is said, your mind is made up.

Hi Whip1, well that's not exactly what I said (by any chance are you a journalist?) ROTFL

I don't know you from Adam but I guess you go into the >75% category. The only thing I can suggest to you is to perhaps actually maybe read the posts.

Lloyd

P.S. If you wish to continue this conversation we can take it off line.

I'll have to get my hubby to find the issue in question, but I read an article last year about an eccentric composter in California who literally had his whole yard built up as a perpetual composting jungle. He took in truckloads of materials from all over the place. The adjoining lot was also used for another huge pile which did catch fire at least once. I am sure his "pile" would not fit your inquiry for home-sized composting, but it was interesting. I think it was in Arthur magazine (music).

Wow, Ya'll are pretty hot about this subject!!
I have seen hay pile in the middle of an open field catch fire (reason unknown). I have seen horse manure in a 5 cu.ft. trash bin catch fire (reason unknown), but I have never seen a compost pile catch on fire. However I have never seen a million dollars or an honest polition, that does not mean that they do not exist!!

Billie

Many times live bacteria have been found in the geysers that shoot up in many places and in the vents on the ocean floor that have temperatures far above 175 degrees. Thermophillic bacteria can be a part of the composting process, generating temperatures much above 175 degrees if not controlled.

Surely you are not implying that the bacteria caused the heat in the geysers and in the vents on the ocean floor? If not, what is the relevance?

Lloyd

Decklap said that bacteria can't live above 175 degrees. I'm positive that Kimmsr is pointing out that they can live above that, and not suggesting they cause geysers to vent.

Decklap said that? Really?

Maybe re-read the posts again. No really, are you a journalist?

Lloyd

Direct quote.
" As noted at several points in the discussion anything much over 175 is going to kill the bacteria."
Do you have a brain? Can you read? Do you have any other insult you'd like to throw around?

Easy guys. There is enough fighting going around. Play nice.

Billie

Billie, we ain't fightin', we's just some good ole boys funnin around.

Well whip my boy, that almost confirms it for me, you really don't read too good. Gotta be a journalist! ROTFLMAO

If you was to actually like maybe read the thread, jbest123 wrote that particular line first on Mar 17 at 19:23 and decklap "quoted" him on Mar 17 at 19:53.

Do I need to tell you how to figure out the timing on that or can you handle it? Or maybe you don't know what a "quote" is never mind a direct quote.

Did ya ever get that backyard problem resolved?

Lloyd

I stand corrected, and I bow to your supremacy. It was foolish of me to misquote the wrong person.

No really, that's okay there whip, I was really smartin' with that "Do you have a brain? Can you read?" remark for a while, then I realized you was just foolin' around with me. Them's are whats called rhetorical questions I bet.

Lloyd

P.S. See Billie, we is getting along jus' fine.

See what happens when you let your thread temperature get over 50C/120F. Let's hear it for Slow 'Posting.

Just to fan the flames on this one (all puns intended), we have a composting professional in San Antonio who is not afraid to share his experience with compost fires. He is not exactly scared of a fire, but he is properly aware that they can happen. His company composts hundreds of materials including animal dung, restaurant leftovers, expired grocery store fruits and veggies, fresh dairy cream, expired soda syrup, brewery leftovers, and (stomp stomp) dead livestock and roadkill. When they put an entire deer or cow into a compost pile, that part of the pile will heat up to 190 degrees F (he has pictures of the thermometer). If the conditions are right (anaerobic as I recall), the decomposition will also generate methane gas. If other conditions are right the methane will not dissipate but will be captured in the pile. Methane, by the way, has a flash point of minus 250 degrees F. The problem comes when oxygen is introduced to the pile either by the pile collapsing on itself or when the turner comes through.

It sounds like some of you are skeptical that spontaneous combustion is a real phenomenon. I'll bet that 200 years ago everyone knew how to deal with linseed oily rags to keep them from catching fire.

Please let us know the scale of the compost piles the company creates. I'm sure the "composting professional" in San Antonio is not talking about little 9 to 12 cubic feet home compost piles that the original poster has asked about. It would seem that composting a whole deer requires an industrial-sized pile with considerably more mass than a home composting bin.

Thank you for the link. It proves conclusivly that rags soaked in linseed oil in a coffee can will ignite. Home gardeners should be sure to not include these materials in their piles.

Seriously, though, the most relevant part of your linseed-soaked rags story is the part that said: 'Lastly, there is a "critical mass" which must be established. A small piece of cloth will lose too much heat to its surroundings. One needs a large enough "pile" to make things work.'

Wayne

I find compost fires to be believable. Before finding this forum I used to pile up those high nitrogen greens from the spring lawn mowing (with no browns), they got really hot. Turn them and it looks charred inside, with ashes. Looks like there was some combustion going on. Thank heavens the interior of the pile didn't get oxygen.

Anyhow, the Alberta Department of Agriculture and Rural Development discusses the mechanisms for compost fires. Link below.

> Here is a link that might be useful: Compost Fires

Yes, another link discussing the possibility of compost fires in large composting facilities, not backyard compost piles which is what we are concerned with here.

"Fires are more common at composting facilities than most realize."

I lost count of the number of times they mention "large." They advise us to "Avoid large piles - no greater than 12 feet high." Thanks. I'll do that.

Wayne

If you follow this thread through it starts life with a concern about backyard piles. Eventually it questions the possibility of any fires in compost and even touches on the possibility that spontaneous combustion itself may be a myth. That's why I posted what I did. None of this is a myth, but I do believe it can only happen in industrial sized piles or in the case of improper hay storage.

The compost manufacturer in San Antonio has windrow piles 22 feet tall and several hundred feet long. They make enough compost each year to completely cover 800 golf courses, and they are not the only mass producer in town.

If we can get back to the original poster, I agree with the general consensus that it cannot happen under normal circumstances (no linseed oil in the pile, heh, heh) to a small backyard pile or bin.

OK folks, let's add some science to this discussion.

From the Ontario Ministry of Agriculture, Food and Rural affairs.
http://www.omafra.gov.on.ca/english/livestock/dairy/facts/hayfires.htm

CBS televisoin
http://cbs11tv.com/local/heat.fire.schools.2.505579.html

Scientific journal "Nature" - but I wasn't willing to pay for the article.
http://www.nature.com/nature/journal/v159/n4045/pdf/159624a0.pdf

US Department of Energy regarding spontaneous combustion in coal.
http://www.saftek.com/worksafe/bull94.txt

There is more info available if you want to search, however, the bottom line is that spontaneous compubstion is real.

I dug up some leaves from the middle of my compost bin that looked scorched. As kimmsr described, they looked intact, but they were gray and ashen. It was just a layer in middle of the pile and it was unlike any of the other compost. At the time it caught my attention and I wondered if it could have burned, but like others have noted, I have never seen my compost go above 160F.

Wow not only have I seen fires at our city's composting facility but we even had mulch fires at some of the local school playgrounds.

Seems if it is over 9 inches tall and damp enough mulch can catch fire.

I have eaten baked potatoes that were cooked in one of the mulch piles at the city's composting facility. The tour only took an hour so that was some pretty hot compost.

I build piles with industrial equipment, large amounts of grass, and a variety of other stuff including carrion in limited amts. My piles go 12' high. Sometimes they get turned every 3 days, sometimes they get 4-5 months of sittin', and in mid-February in Wisconsin (think weeks of 10 degrees and under, w/ overnight lows Cliffs notes: whatever you need to do to get a compost pile to ignite, I ain't doin' it.

If we get 30 of us who have never had a compost fire, that is a different sort of notion than the 'photons from the pile' or 'don't believe in electricity b/c I can't see it.' We're testing whether fire, a visually observable phenomenon, occurs under certain circumstances. We assemble those circumstances, under loose controls, and there is no fire [seen, felt, smelled, or otherwise]. Its a pretty small n, so it doesn't prove much, or maybe it just happens to 20' piles' theory sounds well-informed and convincing and seems to have been largely overlooked.

Like at least one other person had said, it is not all about temperature. It is mainly about too much green (nitrogen) that sits, collects, and gets hot. Nitrogen is extremely flammable and with 140*F + temps could easily explode.

Well.. i've read all of these posts.. and i've read the associated links and stories. Well sir, I don't beleive it.

That is.. I didn't beleive it and thought it was all hogwash, until this weekend.

That's right, this weekend, I had my first compost fire.

It was mid afternoon.. full sun, working in the yard mowing and trimming. It's a good thing I was there to notice it - otherwise, lives would have been taken.

You see, my compost bin is connected to a wooden fence, connected to the house, connected to the daycare centre with ten kids, and a small wounded animal shelter we run on the side with 50+ wounded animals that can only hobble around on whatever legs they have that *aren't* broken.

It started with a puff of smoke. As I was working with the mower, I saw what I thought was a bit of steam - a not uncommon sight in the cool canadian air.

The compost is working good!, I thought.

A few more passes with the mower, hmm.. one of the neighbors must be barbecueing - Better get those steaks off soon or they'll be smoked not grilled!, I thought.

Another pass, some trimming and a glance at the bin - it's really steamin now, WOW, the microherd is REALLY composting the crap out of those grass clippings, I thought.

Now, time for a break and some lemonade as my wife shows up, drinks in hand. "Um, honey - is the compost supposed to be doing that?". Woman, don't question my work, and don't question my compostin' - git back inside. Hmph, she can see that pile a 'steamin like mad, and she wants to question my compostin skill??, I thought.

Back to work now, phhewww it's gettin hot, so hot i can feel when i pass the compost bin it's a radiating like mad! Wow, the wonder of science and nature (speaking of nature, why are there dead rats around the compost bin?) I thought.

Nevermind - there's work to be done!! Woomph.. what was that! Well i'll be - the corrugated roof on the compost bin has collapsed in on itself in a melted heap. If that aint the best dog-gone compostin heap in the world, I thought.

Finished the lawn now, let's sit back and admire the golf-lawn look i've created.. how beautiful - hey, what's that crowd gathering there in the lane, and why's that firetruck in my yard, I thought.

Flames billowing, smoke pouring. It was all over in a flood of water from the firemans house. A category 3 blaze he said. Lucky to be alive, I thought.

So there you have it. I hope my real-life account of a compost fire has opened everyone's eyes, and will serve as a teaching tool for all those out there. Fortunately the fire cheif offered some advice for my next compost, and i've learned a valuable lesson;

Don't compost oil filters, rags soaked in gas, left over paint and used oil. While your at it, don't also then compost cigarettes (lit), because, well, it'll get your composted heated, but could also heat your home and neigbors home too.

esobofh, you all are a funny bunch out in Surrey BC. Do you happen to know Harry Matheson? ARE you Harry?

I think that the final heating to the point of ignition comes not from bacterial activity but from the fact that anytime you put fuel molecules and oxygen molecules together a few of them will combine chemically and release heat. Whether you consider this burning goes back to the definition of fire. I don't know the formal definition but my own personal definition is that fire is a self perpetuating exothermic reaction that builds up in temperature and is limited by the availability of either fuel or oxygen. By the time this happens stuff is glowing red hot (flames).

We are used to viewing objects as conglomerates of unbelievably large numbers of molecules. There is the posibility that one of the atoms that make up your left little toe is at this moment on the far side of mars but you don't really notice that it is missing. The probability that all of your toes atoms should be AWOL all at the same time is infinitely remote, therefore you can be excused for believing that your toe can't be anywhere that you didn't put it, even though parts of it literally are somewhere else sometimes.

Similarly, temperature of an object is the average of the temperature of all the atoms that make it up. Some of your toe atoms are at absolute zero. Some are at 10,000 degrees. The average is 98.6 degrees.

Now, if you create a nice warm stable environment with just the right ratio of fuel to air, some fuel/air couples will "get it on". They give off heat. If the insulation is good, the temperature rises. If the insulation were really really good, all that is necessary is time for the temperature to slowly rise, even without the effect of increased temperature causing an increased rate of chemical reactions.

What I am saying so far is that the chemical reactions that occur in fire can happen at almost any temperature but we don't call it fire until we get the increasing chain reaction where more chemical reaction causes more heat causes more chemical reaction, etc, until the only thing holding things back is a shortage of one of the reactants. Almost always stuff is so hot by then that it is glowing red hot (fire).

I believe that haystacks can start on fire not so much because of 170 degree bacterial activity being the ignition point but because a large enough composting haystack creates a wide enough range of microclimates that one of them will have just the right combination of fuel (methane, cellulose, hydrogen, ethanol, etc) and oxygen, combined with really good insulation and a good 170 degree head start.

I read an interesting thread on the flamability of sprayed on urethane insulation. If you take a chunk of it and put a flame to it it will smoulder and go out but there have been some horrific fires in large metal storage buildings coated with the stuff inside precisely because it is such a good insulator. The heat can't get out. Eventually, by which I mean within a minute or two, temperatures shoot up to the point where anything capable of burning would burn, and so the insulation does. So would wet compost only compost has a high thermal mass and a more modest R-value so it takes longer and the ideal conditions are met less frequently.

The point is to embrace modern physics and the idea that for atoms you can't nail down such mundane physical properties as where they are and how hot they are, only the probabilities of such. These probabilities often have peaks that might lead you to draw sweeping conclusions such as that your nostril hairs couldn't be on fire, while in reality every so often a hair molecule does in fact combine with oxygen and give off heat. It couldn't be otherwise. In a large compost pile, which is almost infinitely larger and better insulated than your nose, there will be pockets that come perilously close to meeting all the requirements for the heat to build up to the point that these chemical reactions meet the criteria for being called fire.

Spontaneous combustion in a home-grown compost pile.

It cant happen.

And Kimm, my hubby was a fire officer in a large metropolitan fire department and he says such cannot occur simply because the amount of heat generated is not enough to make it happen.

Suggesting farm situations is far different than speaking about a home soil bin. Everybody knows about how materials that are dry can self-combust when certain needs are there also. May as well talk about walking on the moon as walking on the ocean floor.
Haystacks, linseed oil, grain silos and other materials are the most noted ones that, under certain conditions, can self-combust.
When was the last time you heard of a grain elevator destroying itself.

Of course there's heat in the Earth....and bringing up the suggestion that since steam rises out of the ocean in places is cause enough to suggest that because the compost is warm to be felt by the hand, is reason enough to have it spontaneous combust is dreaming in color.

Good God.....next you'll have us believe the steam that blew the top off Mount Pelee is under us and only waiting for someone to make a hole in the ground.

A few things which may have been missed, or which may have been hit and I just skipped some messages.

1 - The Autoignition point of something isn't the same as the temp where fire can occur. The flash point of paper is almost 100C lower then the autignition temp of 451C that seems to be quoted over and over here.

2 - All of this assumes "normal" air is the gas in the enviroment. For instance Carbon disulfide autoignites at 200F and is a common biproduct in "rotting" vegitable matter...marshes usually.

Also this is a patent for a "Low temp autoignition combustion) mix. Nitrates being a main ingredient. Not sure if some mix of these are possible, if improbable, in a compost pile. Probably more possible the bigger the pile gets. Also when chemical fertalizers and pesticides are being heavily used.