Assertion: heat | /r/HasSubevent | ignition
Facets:
Source sentences:
text: This amount of coal could cause major problems, because coal was liable to spontaneous combustion when in large piles, especially if they were rained upon, due to the protective dust coating of the coal being washed off, exposing the full porous surface area of the coal of slightly to highly activated carbon below; in a heavy pile with poor heat transfer characteristics, the heat generated could lead to ignition.