And not on the chemical but on the practical use side don't forget that if you do choose an oxygen displacing alternative you'll need to either provide for delay of activation or suppression of activation (better) if oxygen breathing organisms of questionable cognition faculties are present--i.e.: worker bees. Need to keep the gas in the enclosure to maintain the depleted thresholds and got to get the air breathers out before lowering the 02 level.
On Fri, Mar 5, 2010 at 12:33 PM, å... .... <[email protected]> wrote: > FM-200, last I heard, is scheduled for retirement. > Replacement of this agent will be a future issue, even if it > were a desirable choice. > > Novec is another 'clean agent ´, just like FM-200 > was advertized as. Novec is loaded with halogens. > Novec doesn´t -- or isn´t -- intended to act chemically > on fire like Halon did, but it does migrate into the atmosphere > where sunlight breaks the ketone bond. The products > allegedly fall back to earth either hydrated or ionically attached > to detrius. > > What these products do after this point, is a not > well distilled fact. Currently, there is not enough > of it to worry about, or alternatively, enough to > measure easily in the environment. But the fluorines are > highly reactive, and in our children´s > future if not earlier, we will find their insidious effects. > And we are only discussing the end product; there is more > release of product and toxic precursors at the chemical > plant where the 'clean agent' is made. It is not a coincidence > with these concerns over toxicity, teratogenicity and > precursor chemical longevity that 3M no longer manufacturers NOVEC. > > It is not a joke, it is a hoax to assume carte blanche, that > gases saturated in halogens are 'clean´. Novec is not exactly > like, but it is similar to, teflon. Teflon: yes, it is what you are eating > on. > Teflon, when overheated will kill your canary perched in the > next room because pyrolyzate from the teflon are acid forming > and toxic. Literally, the story of a new canary in a new coal mine. > > Kidd´s advise sounded right to me. CO2 or lowering the O2 to > 15%. Low oxygen environments (~15%) will suppress > combustion, regardless as to how that low oxygen concentration is > created (either by dilution using a water aerosol, or by > separating-and-removing > N2 [the lowered O2 stream is subsequently introduced with > simple EXISTING HVAC ducting]). I am receptive to all methods of > accomplishing > our goal (controlling Mr. Fire in our built environments). I hope I am > wrong > in these statements, but until proven so, I don't want to follow the path > previously blazed by the halogenated fire-retardant > chemical industry (Halon, halon-sisters, fluorinated foam, polybrominated > diphenyl ethers, FM-200, etc) who look to be downplaying the collateral > damage > of their product while maximizing profits of their particular industry. > There are viable suppression strategies available, that are not remotely as > harmful. If someone has a valuabe database that is not routinely backed up > at a remote site, perhaps they can revisit that strategy as well. > > scot deal > excelsior fire > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum > > For Technical Assistance, send an email to: [email protected] > > To Unsubscribe, send an email to:[email protected] > (Put the word unsubscribe in the subject field) > -- Ron Greenman Instructor Fire Protection Engineering Bates Technical College Tacoma, WA Member: SFPE, ASCET, NFPA, AFSA, NFSA AFAA, NIBS, WSAFM, WFC _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
