Dictionary Definition
afterdamp n : a toxic mixture of gases (including
carbon dioxide and carbon monoxide and nitrogen) after an explosion
of firedamp in a mine
Extensive Definition
Afterdamp is the toxic mixture of gases left in a
mine following an explosion caused by firedamp. It consists of
carbon
dioxide, carbon
monoxide and nitrogen. Hydrogen
sulfide may also be present, another highly toxic gas.
Afterdamp was the deadly gas which caused the majority of
casualties in the many pit disasters of the British coalfields, and
elsewhere in the world. Such disasters continue to afflict working
mines, especially in mainland China.
Prevention
Having an oxygen
balance of 0 can fully eliminate the release of deadly gases
(see above)- several examples of this: mixing two parts PETN (having an oxygen
balance of -10.1%) with one part ammonium
nitrate (+20%) gives an OB of almost exactly 0. Mixing three
parts calcium perchlorate (+50.17%) with
one part acetone
peroxide(trimer) (-151.2%) also gives these results.
Detection
Gas detectors are available now which detect
toxic gases at very low levels. The Levels
of Gas Detection depend on the methods used.
References
- JS Haldane and JG Priestley, Respiration, Oxford University Press, 2nd Ed (1935)