Afterdamp is the toxic mixture of gases left in a mine following an explosion caused by

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane ...

-rich firedamp, which itself can initiate a much larger explosion of

coal dust Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form ...

. The term is etymologically and practically related to other terms for underground mine gases—such as firedamp, white damp, and

black damp Blackdamp (also known as stythe or choke damp) is an asphyxiant, reducing the available oxygen content of air to a level incapable of sustaining human or animal life. It is not a single gas but a mixture of unbreathable gases left after oxygen is ...

, with afterdamp being composed, rather, primarily by

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is t ...

carbon monoxide Carbon monoxide ( chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simpl ...

and

nitrogen Nitrogen is the chemical element with the symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at se ...

, with highly toxic stinkdamp-constituent

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The under ...

possibly also present. However, the high content of carbon monoxide is the component that kills, preferentially combining with

haemoglobin Hemoglobin (haemoglobin BrE) (from the Greek word αἷμα, ''haîma'' 'blood' + Latin ''globus'' 'ball, sphere' + ''-in'') (), abbreviated Hb or Hgb, is the iron-containing oxygen-transport metalloprotein present in red blood cells (erythrocyte ...

in the blood and thus depriving victims of

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

. Globally, afterdamp has caused many of the casualties in disasters of pit coalfields, including British, such as the

Senghenydd colliery disaster The Senghenydd colliery disaster, also known as the Senghenydd explosion ( cy, Tanchwa Senghennydd), occurred at the Universal Colliery in Senghenydd, near Caerphilly, Glamorgan, Wales, on 14 October 1913. The explosion, which killed 439 mine ...

. Such disasters continue to afflict working mines, for instance in mainland China.

Etymology

The meaning of "damp" in this term, while most commonly understood to imply humidity, presents evidence of having been separated from that newer, irrelevant meaning at least by the first decade of the 18th century, where the original relevant meaning of "vapor" derives from a Proto-Germanic origin, ''dampaz'', which gave rise to its immediate English predecessor, the Middle Low German ''damp'' (with no record of an Old English intermediary). The proto-Germanic ''dampaz'' gave rise to many other cognates, including the Old High German ''damph'', the Old Norse ''dampi'', and the modern German ''Dampf'', the last of which still translates as "vapor".Harper, D. (n.d.). Etymology of fire-damp. Online Etymology Dictionary. Retrieved January 6, 2022, fro
this link

Detection

Animal sentinel Sentinel species are organisms, often animals, used to detect risks to humans by providing advance warning of a danger. The terms primarily apply in the context of environmental hazards rather than those from other sources. Some animals can ac ...

s, such as

mice A mouse ( : mice) is a small rodent. Characteristically, mice are known to have a pointed snout, small rounded ears, a body-length scaly tail, and a high breeding rate. The best known mouse species is the common house mouse (''Mus musculus'' ...

or canaries, are more sensitive to carbon monoxide than humans, so will give a warning to miners. Canaries were introduced into British collieries in the 1890s by

John Scott Haldane John Scott Haldane (; 2 May 1860 – 14/15 March 1936) was a British physician and physiologist famous for intrepid self-experimentation which led to many important discoveries about the human body and the nature of gases. He also experime ...

, the noted physiologist.

Gas detectors A gas detector is a device that detects the presence of gases in an area, often as part of a safety system. A gas detector can sound an alarm to operators in the area where the leak is occurring, giving them the opportunity to leave. This type of d ...

are available now which detect toxic gases such as carbon monoxide at very low levels. They are widely available to protect domestic premises. The levels of gas detection depend on the methods used.

Etymology

Detection

See also

References

Further reading