Posted By Merv Newman Scot, you are going to have to come up with a "worst case" You could be anywhere from a 3M carbon filter to full-on BA sets. In which case get out. Leave the dead. Call the fire brigade. And a few quid for the Widows and Orphans. The last time I got serious chlorine poisoning it was treated by buttered tea. Does wonders for a sore throat. Got married the following week. Is there a connection ? All together : "We've been together now for 40 years (actually 44) " and so forth. I must get these pills changed. Merv

Posted By David Bannister ScotsAM, Merv has it right I think. You need to establish how much Cl gas will be released, for how long and what the concentration will be at its worst. A large scale chlorine gas release will be a major emergency scenario with lots of flashing blue lights whilst a couple of bubbles of the stuff will be at irriation level. Your case (as always) is likely to be between these two extremes and your risk assessment should be good enought to predict your emergency needs. The equipment suppliers should be able to guide you in this matter as they will have undoubtedly been asked similar questions before. Don't forget that Cl gas will damage not only lungs but also other organs and tissue too (eyes, skin, mucous membranes). Merv, I was going to say welcome back but I'm not sure you're quite here yet!