Posted By Brendan Meyler Can anyone please send me any information on what is now the (drop in), or replacement for HALON in fire control systems. Thanks in advance for any replies.

Posted By declan gibney Brendan, a useful website is www.reliablefire.com. FM200 is an environmentally friendly alternative to HAlon with no ozone depletion potential. It is also safe in the event of activation in an occupied location, as it has a NOAEL of 9% and typically works to 7.5% of room volume. It extinguishes by chemically interupting the combustion process. regards, Declan Gibney.

Posted By Ken Taylor A number of us have serious doubts about using the synthetic FM200 and prefer 'Inergen' comprising a combination of naturally-occurring gases. See http://www.inergen.com/

Posted By declan gibney Likewise - any concerns that I have experienced were based on mis-information rather than fact - issues like wearing contact lenses and the toxicity of the gas have all been raised and discounted by Factory MutuaL. I would be interested in hearing the reasons for suggesting inergen over FM200 also.

Posted By Ken Taylor Rather than trying to debate the matter in detail with the restrictions of this Forum (including environmental considerations, cost of recharging systems, whether discharge tests are practical, whether this class of synthetics will eventually be subject to another 'Montreal Protocol' type action lead by the US, unknown synergistic considerations in fire situations, etc) I suggest that you read the arguments set out by the suppliers of both extinguishants (including those available via the Web address that I have supplied in the earlier response) and then take a carefully-considered decision. For my part (in both self and world interest) I prefer to go for gases that we are breathing in and out naturally all day!

Posted By Robert K Lewis All Forgive the question re inergen but the crux of the problem is that at the level of O2 percentage to suppress fire we are also close to the percentages which are able to affect people, even fatally. I know Inergen claim a carefully balanced CO2 figure but is this necessarily safe for all persons? Halon was uncomfortable but did not reduce the O2%ge. In fact I seem to remember it being used as an O2 solvent for use ventilating prmature infants on a trial basis in the states. Apparently it obviated the need for high pressure O2. Comments please Bob

Posted By fred tubb Brendon With the greatest respect to some of my learned friends, that have suggested particular products, do not go this route. There are now quite a few alternatives (note the word) to halon. Firstly what and where is the safty systems required, Two is it a deluge requirement, a life support/escape requirement ect, is it within an electrical instalation. All safety agents have there problems, therefore more than just word or mouth is required. I even wrote my degree thesis on the dangers of safety systems but am still finding thing nearing my bus pass. Contact a local fire engineer or someone who works in this area, or even ring the fire research centre. if may be of any more help i am fred tubb MSc, GIFireE, CFPA(Eur), MIOSH.

Posted By Ken Taylor FE13 (or HFC-23)(CHF3) is another Hydrofluorocarbon but with observable adverse effects recorded at >50%v/v (although O2 depletion would be the important factor before this concentration is reached) and an atmospheric lifetime estimated at 280 years (Loss Prevention Council figures). It was available from Dupont (UK) Ltd but I have not come across this in use.