afterdamp: see damp.

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, another highly toxic gas, may also be present. 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)

See also