UKA051@UKCC.UKY.EDU ("Jack L. Coffman") (02/25/91)
I have been informed by University "design and construction" that the use of halon gas for fire suppresion in computer rooms is "obsolete" due to it being injurious and thus its use is being discredited. Does anyone have any further information regarding this? Has anyone heard anything regarding this? I was even told that there is pending federal legislation regarding this matter. What's the scoop? Jack L. Coffman Security Officer University of Kentucky UKA051@UKCC.UKY.EDU
reschly@BRL.MIL ("Robert J. Reschly Jr.") (03/01/91)
You should really attempt to verify this with a health physicist, but this is my recollection from a recent discussion about this issue locally. As a result, some people in another division were forced to switch to dry pipe water fire suppression for a computer room they are building. The issue initially came up over the concerns for ozone depletion (HALON being a flourocarbon, has been implicated in ozone layer depletion). In any case, at some point during the argument, someone managed to get a hazard data sheet on HALON 1301 if I remember correctly. HALON 1301 is what is commonly put in the handheld HALON fire extinguishers. The large computer room installations are HALON 1211. To the best of my recollection hazard data sheet indicated little risk for short term exposures below 1% concentration (volume, I think), and the only known risk for short term exposure at concentrations between 1% and 4% was a minor heart rate instability in some people, and "increased heart irritability" for 24 to 48 hours after exposure. The data sheet also noted that HALONs tended to decompose at moderate temperatures (order 150 degrees Celsius?), and upon exposure to flame or electrical arc. The decomposition products are moderately toxic, including, if I remember correctly, various phosgene-like products. Also, HALONs are denser than air, and therefore may collect in low lying areas and present an asphyxiation (sp?) hazard. One of the people fighting to keep HALON fire suppression supposedly called DuPont (the makers of HALONs) in an effort to get a data sheet on HALON 1211, but was not successful. He was also told that there were new fire suppressants on the way, but I never heard anything further. You might try contacting them, or checking with the local Fire Marshal, who should have the information or be able to point you in the right direction. Again, fire safety is not my field, though I am an interested lay person (since I have to live with the stuff in our older computer rooms), and I am at home typing this in from memory. I also happen to be pro-HALON since I consider it to be the least disruptive of the currently available alternatives for computer room fire suppression. If something better comes long that does not pose as much of a threat to the environment and poses no greater risk to people or equipment, then I'll be glad to switch. Finally, in case you were interested and didn't already know, the numbers associated with HALONs (and Freons [another DuPont product] in general) are not sequence numbers, but instead refer to the chemical composition. Again from memory, but for HALONs I think the first number is the number of carbons, the second is the number of chlorines, the third, bromines, and the last, flourines in a molecule of the particular HALON. The unaccounted for atoms are hydrogens. Since all HALONs contain only single bond carbon chains, the formula for the total number of other atoms is two plus two times the number of carbons, so hydrogens don't need to be explicitly mentioned. I hope this helps. Later, Bob
FLOWERS@memstvx1.BITNET (Harry Flowers) (03/01/91)
It's true. Halon use is being phased out. Sometime this decade, you won't be able to use halon anymore except for places where evacuation is not an option: air traffic control towers and submarines come to mind. This stems from an international agreement to stop using halon. Unfortunately, no substitute has been found. The last article I read about this (over a year ago) recommended using *sprinklers* with *water tight* computer cabinets. Ha! As a result, halon prices have seen hefty increases each year of the phase-out. As far as I know, this only applies to new installations... I haven't seen any- thing about restricting use of existing installations.
HOWIE@midd.cc.middlebury.edu ("Howie McCausland 388-3711x5754", 802) (03/01/91)
My understanding is that halons are several orders of magnitude more effective
in catalyzing the destruction of stratospheric ozone than the common chloro-
fluorocarbons used in refrigeration, aerosol propellant, etc. I do not know
of federal legislation, but believe a number of pending state statutes require
phasing them out.
I was amused on a visit a couple of years ago to the National Center for
Atmospheric Research supercomputer center to see WATER sprinkler heads in the
ceiling of their CRAY room. On expressing my surprise, I was treated to a
lecture on ozone depletion by their system manager, who said the folks at
NCAR viewed it as a "religious" issue.
Howie McCausland
Assistant Director, Academic Computing
Middlebury College
howie@midd.cc.middlebury.edujcmorris@MWUNIX.MITRE.ORG (Joe Morris) (03/01/91)
Right. The production of halon (and all flurocarbons) is being phased out
due to the environmental problems it causes. As a result it is probably a
poor choice for a new installation, although existing halon systems probably
don't need to be converted yet.
There are some problems (long known) with halon; in particular, one of the
flavors (halon 1201, I think) has the disconcerting habit of decomposing
into phosgene gas when exposed to extremely high temperatures. Other
than this, however, I don't know of any reason to call it 'injurious'.
I just installed a fire protection system in my computer area; we considered
halon but instead went for a water system:
- sprinkler heads overhead only (considered and rejected underfloor heads)
- Dry-pipe system is charged only after two zones report smoke and/or
ionization detection
- Overhead pipe is supervised with compressed air to detect any leaks or
broken sprinkler heads
- Alarm system trips out main power feed and UPS power output 60 seconds
after overhead system is charged unless abort switch activated. The
air handlers are tripped out immediately.
- And, of course, panic switches to trip out the power and charge the
overheads immediately.
I'm not exactly ecstatic about having water in an electrical environment but
what we installed seems to be a reasonable compromise.
Joe Morris
(PS: you're looking at protecting UKCC, say hello to Selwyn Zerof for me.)jgd@dixie.com (John G. DeArmond) (03/02/91)
This has to do with the alledged but far from proven ozone hole problem. Supposidly halons eat ozone and thus cause certain segments of our population to go irrational at periodic intervals. It is unfortunate that halon may get caught up in the Federal Government's equally hysterical response to the "problem" by attempting to ban all CFCs. Whether the CFC scare is real or not should be a side issue when selecting Halon equipment. Considering that Halon is an instaneous fire stopper and considering that Halon leaves no residue and considering that Halon is non-toxic (which does not, of course, mean that you can't suffocate from it.) and considering that the alternative (carbon dioxide) IS toxic and damaging to people and equipment and considering that barring accidental discharge, the halon will remain in its container away from the precious ozone, the decision to use halon as a fire supressant should be simple. It sounds like your administration is being Politically Correct. You can get their attention by asking them to consider the liability consequences and the morality of subjecting computer room occupants to less than optimal and possibly injurious alternative systems. There is more than adequate court precedence for finding liability when someone is aware of safer alternatives at similiar costs and chooses the lesser solution. I've been in a computer room when the CARDOX (carbon dioxide) system accidentally discharged. I feel lucky to have gotten out with my life. Your world instantly goes white and your breath is taken away. I was about 5 seconds from hitting the deck when I got out of the room. You don't even want to consider the other alternatives commonly proposed for computer rooms (water and dry chemical). One accidental discharge and you get to jack up the computer room and slide a new one underneath. John