Ian Gillan makes a good point;  it is almost certainly more likely that fire
will break out, if at all, in the high power gizmos inside the laser power
supply than at the sharp end.  At least we can take sensible precautions
and train people not to cause fires with the laser beam, but we have no control
at all over the breakdown stresses inside the box arising from poor components
or underspecified voltage or power ratings.  I have personally been present
at an exploding laser power supply (on the engineer's commissioning visit!)
but never present when fire has been caused in the laser environment.

This raises interesting risk assessment questions about other possible sources
of electrical fire, such as endoscopy lamps and PDT sources, or frankly,
anything electrically powered in a theatre or clinic environment.  Without
guidelines to suggest fire-fighting precautions, I wonder if these other
devices get overlooked and are assumed to be no risk?

>-- Original Message --
>Date:         Thu, 27 Oct 2005 10:38:43 +0100
>Reply-To:     British Medical Laser Association <[log in to unmask]>
>From:         Ian Gillan <[log in to unmask]>
>Subject: Re: Lasers and fire extinguishers[Scanned]
>To:           [log in to unmask]
>
>
>Al
>Another reference is paragraph 5.5 of BS IEC 60825-8 (Guidelines for the
>safe use of medical laser equipment)
>"Where laser procedures are likely to cause fires, consideration may be
>given to providing CO2 fire extinguishers in a readily accessible
>position near or inside the operating theatre"
>
>Obviously this depends on the outcome of a risk assessment as to whether
>the particular "laser procedures are likely to cause fires". It's
>interesting that this paragraph doesn't consider the possibility of an
>electrical fire in the laser power supply.
>
>Ian 
>
>
>Dr Ian Gillan
>Medical Physics
>Forster Green Hospital
>110 Saintfield Road
>Belfast BT8 4HD
>
>-----Original Message-----
>From: Al Crawford [mailto:[log in to unmask]] 
>Sent: 27 October 2005 09:57
>To: [log in to unmask]
>Subject: Lasers and fire extinguishers[Scanned]
>
>
>Hi,
>
>We're having a bit of trouble with a new fire officer here, and could do
>with some help!
>
>Basically I was wondering if there's any recommendation anywhere about
>the need to have a fire extinguisher in a room or theatre when there's a
>Class 4 laser in use. The only bits of advice I can find in writing on
>this are from a 2003 document by the National Care Standards Commission
>(as was) saying that "there should be an appropriate fire extinguisher
>in the near vicinity of a laser" plus of course the 1995 MDA Guidance
>document which says that "there should be easy access to an appropriate
>fire extinguisher".
>
>For many years we've insisted that there be a CO2 extinguisher mounted
>inside a laser room or theatre, and in our rules we say that laser users
>should know where the extinguisher is and how to use it in the event of
>any incident.
>
>This new fire officer is saying that he doesn't see the need to have an
>extinguisher in the room, since there is one nearby (actually down the
>corridor and round the corner - I have visions of people rushing
>frantically in all directions trying to find the wretched thing!). He
>would, however, concede the use of a fire blanket within the room or
>theatre.
>
>Does anyone know of any concrete advice or recommendation that we could
>throw at him on this one, or indeed any consensus view among LPAs (if
>such a thing is possible!) on this topic? Or should we just go along
>with what he's saying?
>
>Thanks in advance for any help you can give!
>
>
>Al.
>
>-- 
>
>Dr Al Crawford
>Medical Physics Department
>Queen's Medical Centre
>Nottingham NG7 2UH
>UK
>
>[log in to unmask]
>
>
>
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-----------------------------------------------------
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GLOUCESTER, GL1 3NN, UK.
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