Posted By John-Mark Does anyone have details of suppliers of Personal CO2 Gas Monitors, for use in places like Pub Cellars etc? JM

Posted By Jane Blunt I would recommend a proper CO2 monitor (Internet search engine should give you some pointers). While carbon dioxide would be an asphyxiant, it is actually toxic in its own right, and the BOC booklet on cryogens suggests that it is likely to be fatal at a concentration of 9% after about four hours. A concentration of 9% carbon dioxide would reduce the level of oxygen to around 19% (if my arithmetic is correct). Therefore, although an oxygen monitor, set to go off at 19.5% might be helpful, I would prefer the carbon dioxide monitor. Jane

Posted By Paul Swift Try Safety Provider at www.safetyprovider.co.uk. They do a reasonable range of multi- and single gas detectors.

Posted By jom Yes, I'd like to know more about the toxic angle. We all have CO2 in our bloodstream all the time. J.

Posted By Paul Leadbetter Thanks, Jane I'm not convinced, though; if the reported toxic effects are actually due to reduced oxygen levels that does not necessarily mean that CO2 is toxic. Paul

Posted By Descarte I think it is to do with how readily it binds to the hoemoglobin in the blood (binding coeficient) however I only thought that this was a problem with carbon monoxide as this can bind more readily than oxygen, or is harder for the body to remove.

Posted By Andrew Wilson JM, We use similar equipment on our sites and our supplier is BW Technologies who supply a wide range of Gas Moniotrs, personal, portable and static. Web address is: www.gasmonitors.com Hope this is of some help

Posted By Diane Thomason Jane is spot on; CO2 is toxic in its own right, it is NOT just an asphyxiant. There is a lot of confusion about this with many people believing that CO2 works as a simple asphyxiant. It has a WEL of 5000ppm. At 5-10% you would feel tired, with laboured breathing, get headaches, tinnitus, impaired vision and become confused - unconsciousness could then follow. This is due to toxic effects of CO2 and NOT lack of oxygen. Toxic effects from CO2 can occur when there is still plenty of oxygen in the atmosphere, i.e. a concentration of oxygen that would still be safe if the CO2 was not elevated. In a typical situation, if CO2 became elevated to 4% - a hazardous level - the oxygen would still be 20%, a perfectly safe level of oxygen that would not set off an oxygen depletion monitor. Jim is spot on too - monitor the area to prevent people ENTERING a hazardous are; rather than provide personal monitors that tell people that they are already in one! I've produced some guidance on this, if anyone's interested just email me. Diane

Posted By Marcus74 Try here: http://www.crowcon.com/ We have just ordered CO monitors from this company for exhaust extraction but you can specify the type/amount of gasses you want the hand helds to monitor. I believe Oxygen and CO2 are on the list.