# Is compost flammable? **URL:** \ **Category:** Factual Questions\ **Created:** [April 21, 2012, 8:56pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535 "2012-04-21T20:56:54Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Weaver](https://avatars.discourse-cdn.com/v4/letter/w/3d9bf3/32.png) [@Weaver](https://boards.straightdope.com/u/Weaver)\ **Post date:** [April 21, 2012, 8:56pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/1 "2012-04-21T20:56:54Z")
Is is possible to burn compost? I ask because it came up in another thread and I’ve been wondering about it. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [April 21, 2012, 9:24pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/2 "2012-04-21T21:24:09Z")
It’s usually damp, but if you dried it out, I’m sure it would burn (poorly). Here’s an article: [Compost pile will burn in Palo Alto for days](http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/07/24/BA1311UPN6.DTL&type=printable) ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [April 21, 2012, 10:05pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/3 "2012-04-21T22:05:11Z")
sure it can. as mentioned it is usually too damp. grass piles will start on fire as some decomposes and all of it dries. grass piles need to be turned to let out the heat and be isolated from nearby combustibles. ---
**Author:** ![Gatopescado](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gatopescado/32/5711_2.png) [@Gatopescado](https://boards.straightdope.com/u/Gatopescado)\ **Post date:** [April 22, 2012, 4:53am UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/4 "2012-04-22T04:53:02Z")
In some cases (so I have read, but I can’t imagine it happening in real life), the heat from decomposition will set a compost heap smoldering. Don’t know if I would consider it “flammable”. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [April 22, 2012, 5:10am UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/5 "2012-04-22T05:10:19Z")
> [@Gatopescado](#): > > In some cases (so I have read, but I can’t imagine it happening in real life), the heat from decomposition will set a compost heap smoldering. Don’t know if I would consider it “flammable”. Try busting open a compost heap that is already smoking, letting in oxygen. And stand back when you do it. I mean, really, what are they teaching in school if people think spontaneous combustion is imaginary? > **[Spontaneous combustion](https://en.wikipedia.org/wiki/Spontaneous_combustion)** > > Spontaneous combustion or spontaneous ignition is a type of combustion which occurs by self-heating (increase in temperature due to exothermic internal reactions), followed by thermal runaway (self heating which rapidly accelerates to high temperatures) and finally, autoignition. It is distinct from (but has similar practical effects to) pyrophoricity, in which a compound needs no self-heat to ignite. The correct storage of spontaneously combustible materials is extremely important, as improp ---
**Author:** ![Una\_Persson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/una_persson/32/346_2.png) [@Una\_Persson](https://boards.straightdope.com/u/Una_Persson)\ **Post date:** [April 22, 2012, 5:30am UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/6 "2012-04-22T05:30:44Z")
Large ones used in commercial applications do self-heat and combust, and thus we specify fire detection and suppression equipment when we design biomass handling facilities. A large part of the issue is a modest amount of self-heating, combined with poor heat transfer and a large amount of biomass with a relatively low ignition temperature, plus a large amount of the combustible matter in the form of _volatile_ solid, liquid, and gaseous products. Edited: and yes I’ve seen it happen. ---
**Author:** ![Chuck\_Norris](https://avatars.discourse-cdn.com/v4/letter/c/85e7bf/32.png) [@Chuck\_Norris](https://boards.straightdope.com/u/Chuck_Norris)\ **Post date:** [April 22, 2012, 7:30am UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/7 "2012-04-22T07:30:49Z")
Am I right in thinking that compost is one of the ingredients used in making home-made explosives? Perhaps because of its ability to self-combust? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [April 22, 2012, 9:58am UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/8 "2012-04-22T09:58:20Z")
> [@Chuck\_Norris](#): > > Am I right in thinking that compost is one of the ingredients used in making home-made explosives? Perhaps because of its ability to self-combust? Don’t know what you’re thinking of exactly. But compost is often used as a source of nitrates. Wood ash and compost can be used to make potassium nitrate, the primary ingredient in gunpowder. ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [April 22, 2012, 2:42pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/9 "2012-04-22T14:42:18Z")
Several years ago in my neck of the woods, the local counties started their own composting facilities. In each and every case, within weeks of opening they had fires. There’s a learning curve in figuring out how to really get things cooking while keeping things from burning. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [April 22, 2012, 6:21pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/10 "2012-04-22T18:21:08Z")
> [@Una\_Persson](#): > > Large ones used in commercial applications do self-heat and combust, and thus we specify fire detection and suppression equipment when we design biomass handling facilities. You can even do it on a small scale in your backyard! I think that part of the confusion comes from the word “spontaneous,” often used to describe things that ain’t: Spontaneous Generation - No, mice are not created from a mess, but they do like moving in when they find one. Spontaneous Human Combustion - Probably not, as the incidence seems to have lessened since more drunks have stopped smoking. Though the results, like the lady’s unconsumed legs beneath her armchair, can be wicked cool, however they were caused. Spontaneous Combustion - Yep, happens all the time. ---
**Author:** ![Mangosteen](https://avatars.discourse-cdn.com/v4/letter/m/6a8cbe/32.png) [@Mangosteen](https://boards.straightdope.com/u/Mangosteen)\ **Post date:** [April 22, 2012, 6:57pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/11 "2012-04-22T18:57:42Z")
I’m a landscape contractor and we spread lots of compost. When we pick it up locally, often times (especially in the early morning) its smoking and _hot_ to the touch. There is a sprinkler system set up near the plies that cool them off periodically. One time we has a large order delivered to a home. We arrived after the delivery truck left. It was smoking so much that the woman who owned the home called the fire department and they had a hose on it when we arrived. (Thanks, guys! How are we going to spread that muddy mess you just created?) ---
**Author:** ![postcards](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@postcards](https://boards.straightdope.com/u/postcards)\ **Post date:** [April 22, 2012, 7:26pm UTC](https://boards.straightdope.com/t/is-compost-flammable/619535/12 "2012-04-22T19:26:34Z")
> [@Gatopescado](#): > > In some cases (so I have read, but I can’t imagine it happening in real life), the heat from decomposition will set a compost heap smoldering. Don’t know if I would consider it “flammable”. [Tell that](http://newyork.cbslocal.com/2012/04/11/health-concerns-arise-following-staten-island-compost-fire-at-fresh-kills-landfill/) to [the FDNY](http://www.silive.com/news/index.ssf/2012/04/staten_island_compost_fire_und.html)!