Coal’s Spontaneous Combustion Problem

Coal fires are a given, but what are the risks?
This post is part of the research project: Northwest Coal & Oil Exports
Photo courtesy of Paul K Anderson. Used with permission.

Photo courtesy of Paul K Anderson. Used with permission.

Those who are evaluating export proposals might do well to examine one little-talked-about peculiarity of Powder River Basin (PRB) coal: it has an unfortunate tendency to spontaneously combust, even in rail cars and stockpiles.

To be clear, it’s not as if coal trains will be delivering blazing cargoes. The threat is likely to be more insidious—slowly smoldering coal that is perhaps emitting noxious gases into neighboring communities. Yet the severity and toxicity of these gases are largely unkown.

Does self-ignited coal pose a genuine pubic health risk or is it little more than a handling annoyance for coal shippers? We don’t know. But we do know that even the coal industry says self-ignition is a problem:

Operators familiar with the unique requirements of burning PRB coal will tell you that it’s not a case of “if” you will have a PRB coal fire, it’s “when.”

In fact, one technical analysis—demonstrating that “PRB represents the extremes of handling problems”—found that:

Spontaneous combustion of coal is a well-known phenomenon, especially with PRB coal. This high-moisture, highly volatile sub-bituminous coal will not only smolder and catch fire while in storage piles at power plants and coal terminals, but has been known to be delivered to a power plant with the rail car or barge partially on fire…

Needless to say, even low intensity fires are potentially troublesome for communities near stockpiles or along rail corridors. Yet it’s hard to evaluate the magnitude of the problem.

I’m not aware of any scientific study that has looked at the health risks of spontaneously combusted Powder River Basin coal. (There is ample occupational safety literature for coal facility operators.) That said, there is reason to worry that smoldering coal emits harmful pollutants:

Though Powder River Basin coal does not spontaneously explode or burst into full flame (at least not outside of confined environments) it is clear that under the wrong conditions it can self-ignite and burn slowly while traveling in a rail car, standing in a stockpile, or moving along a conveyor system.

We don’t know enough to understand the risk of hazardous emissions from smoldering coal. But the problem is worrisome enough that Northwest officials should carefully evaluate the health and safety risks to ensure that large coal shipments would not threaten local communities with spontaneous combustion problems.


Thanks to Kathy Washienko who provided invaluable research assistance.

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  1. Russ Maddox says:

    I just read your piece on spontaneous combustion and wanted to add a few personal observations. Alaska’s coal is very similar to PRB coal ( high moisture content low-rank sub-bituminous coal). We have “hot-spots” in the stockpiles regularly. The coal export facility in Seward, Alaska’s design is flawed because a large portion of the stockpiles are not accessible for fire fighting and in the case of high stockpiles in order to put the fires out they need to be able to spread the pile out thinly to let the hotspots burn out. We simply don’t have that much space to work with. We often see bulldozers going back and forth over a smoking spot and learned that they are trying to compact the coal to squeeze as much air out as possible to choke the fire out. We had one large incident in the past that scared the bejeezus out of everyone. Since then our stockpiles and volume going through town have doubled. And now businesses have built with 100′ of the piles right on the shared property line. With our two massive stockpiles running N-S side by side with the conveyor in the middle if we were to have a large fire on the north end in high winds (which are frequent) and knowing there is zero access from the west side where the neighbors (campuses and a bunkhouse no less) are all located could be a recipe for disaster. When our facility was built there was zero consideration of such an event. As they ramp volumes up more and more we are getting more concerned. Our local FD doesn’t even have a ladder truck or pumper that could effectively reach all of the stockpiles. Seeing the EPA letter to the Port of Morrow and ACOE it at least appears this may be considered in their cumulative effects study in the NW. I wish they would do a full risk or hazard assessment as well. We have a diesel tank farm a couple hundred yards away, too. All of these issues should have been studied before we let them in our community. Hindsight is 20/20.

  2. Terry Wechsler says:

    Great article, Eric. Thanks for the resource, and for drawing attention to this issue for scoping.
    Great industry paper on preventing coal fires on conveyors (because combustion is “a given”):

    Re coal fires on ships: Note the discussion about monitoring emissions of gasses, particularly CO and methane. I believe the issue with covering coal gondolas on trains is that smoldering coal off gasses methane which will eventually explode.

    • D. Brad Hurley says:

      I have been a ship charter broker for over 25 years and have done hundreds of thousands of tons of coal without any safety incidents. I would say that shipping grain is more dangerous and subject to spontaneous combustion. It can be done, safely, relatively cleanly, and you won’t even know its happening, which is what we want, right?

      • Samir Shah says:

        Dear Brad Hurley,
        When the coal is stored inside the ship, do you face Spontaneous Combustion?
        What about the gas issues that personnel face in such confined space?
        Any experiences, personal or heard from others on this?

  3. NWS says:

    This is just one more reason why we need to slap major taxes on coal. There is massive externalized cost that needs to be recovered. Also, it would not hurt to set a precedent to start taxing carbon. Can we tax rail/ship transportation services due to federal jurisdiction or are we stuck just hitting the terminals? What happens if the supreme court hammers the commerce clause in the health care ruling? Also, it would not hurt to open up liability rules for coal transport. Turn the litigation sharks on coal for the slightest excuse. It seems like there are just too many of these whack a mole terminals to stop all of them, so lets use states rights for some good.

    • Steve Erickson says:

      Directly taxing transportation for something in interstate and international shipment would almost certainly run afoul of the Commerce clause.
      But I like your idea of citizen attorney general provisions in state environmental laws. It would make a huge difference in enforcement. Currently enforcement falls mainly to low budget citizen groups. The ability to recover costs from miscreants and overly pliant agencies would be a huge improvement and really level the playing field..

  4. Ramesh Kalagnanam says:

    Is there some source of information that gives a comparison of propensity for spontaneous combustion for different coals (Illinois Basin, Central App, Northern App, PRB, etc.)?


  5. sivanarayana maganti says:

    spontaneous combustion in coal, as an underwriter, is a very interesting topic.I have come across a claim pertaining to S.C loss in coal stored at krishnapatnam port Andhrapradesh India. The coal of very high volume of 69000 M.Ts stored as a single heap. Such a hugh heap developed HOT- SPOTS at many places and S.C ocured and fire fighting eforts are futile. After going through the above discussions I opne the following reasons for the S.C .
    1.size of the heap which is inaccessible
    2.Long duration of storage
    3.lack of knoweledge about the properties of coal to decide open storage methods.
    4.Absence of periodical stirring of heap
    5. Immediate removal of coal on completion of coal at port yard.

    • Samir Shah says:

      Mr. Sivnarayana Maganat,
      Do you know what was the height of the stock pile at the peak and
      how long the pile stayed before the SC?

  6. Govinder Kapoor says:

    Is there any published material available on what the maximum height of a coal stock pile should be, and what fire fighting measures should be in place, before stocks are piled in the open?

    CVan someone, please, direct me to the available literature?

  7. Katinka van Straaten says:

    Good day,
    This piece mentions the following research:
    A study of spontaneous combustion in coal fields in South Africa found that the coal fires emitted a range of gases, including toxic substances, carcinogens, and heavy metals. (This study focused on coal mining sites, which can have rather different characteristics than stockpiles.)
    Could you please tell me where I can get hold of this research.
    Your assistance will be highly appreciated.

    • Eric de Place says:

      Sorry, that link was broken. It’s fixed now in the post above. You can also find it here:

      Pone et. al, The spontaneous combustion of coal and its by-products in the Witbank and Sasolburg coalfields of South Africa, International Journal of Coal Geology, Volume 72, Issue 2, 1 October 2007, Pages 124–140

  8. dudeson says:

    we do in fact know plenty about the gases and things emitted from burning coal every coal mine test their coal for the BTU’s sulfur content and other materials offended when burn on a daily basis do some research before you posted article is a rarity that cold catch the fire happens quite often in the mining process they just put a little dirt on it to snuff out the oxygen and problem solved not a big deal

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