Fire suppression

A large cultural institution is considering using the gas fire
extinguishing agent FM200 (HCF 227a) to replace Halon 1301 (the
system has already been removed).  This will be used in a painting
store (paintings on vertical mesh racks), works on paper stored in
Solander Boxes, and a small objects store (objects in glass-fronted
wooden cabinets).  A number of concerns have been raised about the
possible impact of FM200 on collections.

    1.  The total volume of gas is discharged in approximately 10
        seconds creating considerable air turbulence, which may
        dislodge small objects in its path (store rooms invariably
        have small or lightweight objects lying around).

    2.  At the discharge nozzle the gas has a low temperature of
        less than -16 degrees C, although it is claimed that within
        15 seconds the gas will come to equilibrium with the room
        temperature.  This freezing gas, if in direct contact, may
        affect some artworks.

    3.  The first time the system is used there is potential for
        oil, water and corrosion products left over in the pipes
        during installation to be discharged into the room.

    4.  FM200 (as was Halon 1301) is a very expensive gas, and it is
        known that some institutions never actually tested the Halon
        system due to the high gas replacement cost.

    5.  It is stated that when FM200 is heated, such as by open
        flames, breakdown products, including hydrofluoric acid (HF)
        may be formed.  This is toxic, a throat irritant and is a
        highly corrosive acid.

A search in the CoOL archives revealed very little on these
problems, the only source being about Halon (which seemed to have
similar problems). Here pegboard sheets were used to deflect the gas
but allowing gas penetration.  When the system was tested moisture
condensed on metal pipes and gas discharge nozzles causing them to
drip (hopefully not dilute HF acid).  In one area it actually
started snowing.

Details of experiences as to whether these perceived problems are
significant would be much appreciated.  I realise that the use of a
water micro-mist system may be suggested as an alternative, but for
a number of reasons it is currently considered not the best option.

Professor Colin Pearson
Co-director
Cultural Heritage Research Centre
University of Canberra
ACT 2601, Australia
+61 2 6201 2368
Fax: 61 2 6201 5419


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                  Conservation DistList Instance 15:6
                  Distributed: Tuesday, June 26, 2001
                        Message Id: cdl-15-6-009
                                  ***