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What Gases Make Coal Mines Dangerous?
Credit: 350jb | Dreamstime

Working in a coal mine can be dangerous even if it hasn't collapsed or exploded. Rocks naturally emit gases and corrosive chemicals that can harm humans, and carving up those rocks can hasten the release of those gases as well as tiny particulates that can lodge in a miner's lungs .

Airborne hazards are called "damps" probably a reference to the German word "dampf," which means vapor and generally break downinto the following categories:

A "black damp" is a mix of carbon dioxide and nitrogen caused by corrosion, a process that can cause suffocation by drawing the oxygen from the air.

An "after damp" includes the same gases as a black damp, plus carbon monoxide, and usually forms after a mine explosion.

A "fire damp" is particularly dangerous, because it consists mainly of methane, a flammable gas.

A "stink damp," which reeks of rotten eggs, is mostly hydrogen sulfide. This gas, too, can explode.

A "white damp" is any air containing carbon monoxide, a gas that has no discernable scent but is toxic in even low concentrations.

Decades ago, miners placed canaries in the mines as an early warning system. Because of their small body size, canaries were more vulnerable than the miners to low levels of toxic gases. If a canary stopped singing or keeled over, the miners knew they needed to get to the surface.

In modern mines, canaries have been replaced by gas monitors and other electronic noses.

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