Changes

When coal is mined, fissures and pores in the coal bed in which methane is lying are exposed, release releasing methane into a the confined area a gas that . This can be dangerous because methane is not only highly flammable , with the potential to violently explode in a ball of flame , but one that is also an asphyxiant, capable of driving out oxygen, and causing death by suffocation. A build up of hazardous gas in a mine is known as a damp. Methane , with methane build-ups are called “fire damps”. Carbon monoxide accumulation, also called “white damp” adds to these dangers. When methane combusts, this highly toxic and flammable gas is generated as a by-product and spreads through a mine’s labyrinth of tunnels and shafts. [[Coal dust]] also reacts badly to a methane explosion. As part of a violent chain reaction, it can burst into flames in a series of secondary explosions throughout a mine.<ref name="mgd">[http://www.methanegasdetectors.com/info/coal-mining-and-the-risk-of-methane-gas-explosions/ "Coal Mining and The Risk Of Methane Gas Explosions"] Methanegasdetectors.com, accessed September 2010.</ref>

The properties of methane make it difficult to detect without equipment. It is colorless and odorless, so there are no obvious physical signs such as coughing or streaming watering eyes to warn of its proximity (, although it will cause suffocation if it builds up in a badly ventilated space). It is also difficult to assess how much methane is likely to be freed from a particular coal bed – factors such as coal type, the depth of the mine, and the geologic age of the coal strata all play a part.<ref name="mgd"/>