Hi,

this has probably been covered numerous times on here but could someone explain about bad air to me?  Mainly I would like to know how much of a problem it generally is in caves and the signs etc.  I have read somewhere that using a cigerette lighter can help to guage the air quality and if it won't light then that is a sign of very bad air?  However I have always been under the impression that naked flames underground are dangerous.

Thanks in advance.

In natural caves in the UK as opposed to mines, the chances are that "bad air" refers to Carbon Dioxide (CO2). Unlike coal mines and some other types, you are very unlikely to meet Methane in caves - probably your impression about naked flames.

Her is a link to some information on CO2.

Luckily CO2 is only found in a few caves, often only in certain parts of the system and levels seem to be seasonal. The source is almost always decaying organic matter.

There have been very few incidents of the much more dangerous gas Carbon Monoxide (CO) found in caves - usually connected with explosives or due to internal combustion engines.

http://ukcaving.com/board/index.php/topic,7246.0.html
http://ukcaving.com/board/index.php/topic,3609.msg49531.html#msg49531
http://ukcaving.com/board/index.php/topic,2385.msg25110.html#msg25110
and more besides; just use the search function.

Thats great thanks guys

Stink Damp; wet Damp; are all based on Methane build up in a wet seam where there might be rotting moss, lichen or other underground life. If allowed to reach a formidable size, a spark (such as a cigarette lighter) or a hob-nailed boot on stone, will definitely cause an explosion that will most assuredly put your lights out permanently - Beats carbide, the metal Sodium and the metal Potassium for explosive affects as many coal miners have witnessed - usually from the Pit-head rather than in the mine itself (including self) . Not good! You will find methane in coal and other kinds of mine's but not in a salt mine - the main problem here is any dampness getting into a salt mine would couse the salt to dissolve with disastrous results - since the 'galleries' are held up by large buttresses of salt (keeping the roof up) if this collapsed, so would Nantwich, Sandach and other towns (in Cheshire) where salt was mined 700 metrwes down beneath their feet! linuxfanatik