The revised standard for the selection & positioning of extinguishers is out at BSI's draft website.
- Powder now not generally suitable for any indoor use due to discharge cloud/secondary damage as oppose to old 'hotels, hospitals, assembly' restriction (can still be provided but only after consultation with client and usually for industrial premises only)
- Now specifically requires signs
- No provision of Class C rated extinguishers any more unless site has dedicated trained fire fighters due to explosion risk so Powder will no longer be required in Boiler Rooms etc
Where did you come across these bits AB?
Powder no longer advisable indoors"5.4.3 Use of powder extinguishers
The discharge of a powder extinguisher can cause a sudden reduction of visibility, which
could temporarily jeopardize escape, rescue or other emergency action. For this reason
water-based extinguishers should ideally be specified for use indoors"
Signs"The position and type of a fire extinguisher should be indicated on a sign so that, if the
extinguisher is removed, this can be identified during a safety inspection, and a replacement
ordered.
NOTE 2 Attention is drawn to legal obligations in respect of indicating the location of fire-fighting
equipment."
Class C"8.4 Class C – Fires involving gases
8.4.1 General
If a trained fire-fighter is not at the scene of the incident, the only safe method of
extinguishing class C fires is to cut off the flow of fuel to the leak. Locating and operating the
flow control valves is therefore the preferred method of extinction. These actions should be
carried out as a matter of extreme urgency.
If this cannot be done immediately, two opposing fire hazards are possibilities. These are:
a) the jet of flame, contrasted with b) the filling of a volume with unburnt gas. A gas reservoir
with free access of air will be liable to re-ignition at any time, possibly with explosive force.
Unless the jet is playing directly upon some other combustible material, which should be
covered with an appropriate extinguisher as recommended elsewhere in Clause 8, allowing
the flame to continue is the least dangerous option until the flow can be stopped.
8.4.2 Minimum quantities of class C extinguishers required
None are required unless a trained fire-fighter is available (see 8.4.1).
8.4.3 Additional extinguishers to the minimum scale of class C provision
None are required (see 8.4.1)"