Ammonia

[Simon M]

Can the alarm for an Ammonia leak be the same as that for a fire evacuation.  I know that 5839 say it must be different but the Chem Industry say the fire alarm system can be used as a warning.

Your thoughts around the topic will also be gratefully received.

[kurnal]

Industry bodies often think that they can hijack fire alarms for other purposes but in reality it needs to be fully thought through. Bomb scares being another example.
It may be unwise to use the same alarm system because this will invoke the standard fire evacuation procedure. Will all exit routes and assembly areas be safe and appropriate in the event of the ammonia leak? Could weather conditions, wind direction be an issue? Will persons responding to a fire alarm be also looking for sign of ammonia in choosing their route? Is the ammonia alarm automatic or manual? if automatic what are the implications for firefighters? It is much wiser to carry out a seperate risk assessment for the chemical leak and put in place bespoke, appropriate alarms and proccedures.

[John Webb]

You do not say what sort of FA system you currently have. If a bell/siren type then you ought to have something different as kurnal points out. If a voice system then a different warning signal and appropriate announcements would be OK. Does the site have a PA system that could be upgraded, perhaps?

[Paul]

Simon,

You must be very careful in using the same tone as the fire alarm system as that of any warning tone used to notify persons of a toxic substance release, such a Ammonia.  I'm not sure where you have your information from regarding what the Chemical industry do in this instance, but I have caried out such work within the Chem / Pharms industry and never have I once seen the alarm system used to warn of a toxic gas release.  Especially with the EA breathing down conpanies knecks with the liklihood of a MATTE scenario, as in many cases this will present.

If your emergency procedures dictate that everyone must evacuate the premise on hearing the toxic gas alarm you must be exercise the due diligence to ensure staff are aware of the appropriate place to assemble, as this may not be possible due to wind direction etc.  If you were to evacuate staff on hearing a fire alarm tone and in actual fact it is the same sound as the toxic gas alarm then staff will not be aware of what is required of them.

Personally I would be careful in taking persons into the open air if such an incident has occurred, may be worth establishing ‘safe rooms’ and keeping people inside until its safe to resume normal activities.  Again, the only way you would ensure staff stayed inside would be to have a completely different tone.

Many things must be considered, but ensuring staff are aware of a toxic gas release is essential and the only way in doing this is by a separate warning system.

You may also have to consider the bigger picture.  As you will be aware under ‘COMAH’, you must ensure domestic properties / adjacent businesses are also considered in this plan and the only way this will happen is with a loud warning system.  

I think we have spoke on this before Simon, can’t remember??

Thanks

Paul