Natural Gas and Carbon Monoxide Flashcards
Operational procedures at large main or gas site or transportation
5.1
It will be very obvious from the noise that a high pressure natural gas pipeline has been ruptured.
5.2
The IC must establish a minimum 200 metres hazard zone. Crews working within this zone to affect rescues must have full PPE and BA.
5.3
Under “congested” conditions a hazard zone of a minimum of 600 metres should be established and consideration given to 6.8 below.
5.4
The IC must inform the National grid and request that the supply is shut down via control; however, it will take a considerable time to shut the supply down.
5.5
No attempt is to be made to control the leak by fire crews.
5.6
No attempt is to be made to extinguish the fire where the leak has ignited.
5.7
Surrounding risks may be protected from flame and heat impingement only when crew are not placed in undue danger.
5.8
Where there is an uncontrolled leak from a massed storage site, crew should withdraw to outside of a 1000 metres hazard zone and await the advice of the hazardous materials and environmental protection officer (HMEPO).
804 Issue date: 1 October 2012 5 of 13
5.9
At this point the IC may have sufficient information to initiate any special operational procedures based upon the scale of the gas leak, see Policy number 263 - Major incident procedure.
5.10
Rendezvous points (RVPs) or marshalling areas must be considered so as to avoid being overwhelmed by appliances. These RVPs may need to be some distance from the incident to avoid crew and appliances being placed in the hazard zone. Once determined, their locations should be sent to Brigade Control using the appropriate message, see Policy number 518 – Messages from incidents.
Operational procedures at domestic and low pressure sites
Where a leak in the natural gas supply is suspected, a cordon to ensure public safety of a minimum of 25 metres is to be maintained and advice sought from the GA. Consideration should be given to whether additional resources are required.
5.12
Site employees, particularly engineering, safety staff or other reliable witnesses, should be enlisted to assist in establishing the presence of a natural gas leak.
5.13
Crews may be committed to shut off the gas supply only where they are not put at risk from a gas explosion and must have donned BA and full structural PPE to mitigate the effects of any sudden flaming from ignited natural gas. This should only be undertaken where there is a risk to life in surrounding buildings or critical infrastructure. The responsibility for the safety of the gas supply rests with the GA, see Appendix 2
5.14
Before entering a building suspected of having a natural gas leak the following must be considered:
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Removal of ignition sources, e.g. can the electrical supply be isolated externally.
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Shutting off the natural gas supply from the outside.
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Ventilating to property prior to entry to remove explosive atmospheres.
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Personal protective equipment full structural firefighting kit with BA.
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Detection identification and monitoring equipment carried on the fire rescue units to alert crew of the presents of and explosive atmosphere. Policy number 797 – Detection identification and monitoring instruments refers.
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Intrinsically safe equipment.
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Communications: B.A.R.I.E. must be used as fire ground radios are not intrinsically safe and must not be carried into these environments. Please see Policy number 592 – Breathing apparatus radio interface equipment.
5.15
Where a natural gas leak has ignited, the flames should not be extinguished but surrounding risks should be protected by lashing jets in place and evacuating the area until the gas supply has been isolated.
5.16
The fire service does not have powers of entry at gas leak incidents for the purpose of securing the gas supply. However, the GA does. Crews should not make an entry on behalf of the gas authority unless there is an exceptional public safety issue, see Appendix 3.
5.17
Following a fire consideration must be given to the possibility that gas apparatus may have been affected by radiated heat or temperatures above normal which, if excessive, could affect the integrity of the sealants within the apparatus and may result in a leakage of gas. Where the IC has reason to suspect that damage to gas apparatus has been caused a request for the attendance gas authority should be made in accordance with Policy number 518 - Messages from incidents,
Operational action at Carbon Monoxide incident
5.18
A single breathing apparatus (BA) crew may be committed to ventilate when responding to a domestic carbon monoxide detector actuating having regard to the following points:
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Calls to domestic CO detector actuating are level 1 incidents and the GA must be requested simultaneously as part of the level 1 attendance;
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CO is lighter than air when heated and will accumulate at the highest point in the building. As it cools it will potentially dissipate through all rooms adjoining the room of origin therefore all room must be ventilated not just the compartment of origin.
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Turn off and isolate the natural gas supply to all gas appliances in the premises.
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Leave the duty with the GA or their representative.
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BA must be worn even though this may appear to be unnecessary as small doses of CO can accumulate over time and crews may become ill if exposed to repeated small doses.
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A single pumping appliance should be sufficient as BA is required only to prevent accumulation of small doses of CO. Where larger concentrations are involved the incident may need additional resources.
5.19
Where calls to CO incidents indicate there is a suspected large release or persons are reported trapped, a minimum level 2 attendance will be required.
5.20
If persons are involved, rescue should be the IC’s prime objective.
5.21
The RA must take account of the possible presence of irrespirable and or flammable atmospheres and the environment must be monitored using the appropriate detection and monitoring equipment carried on the fire rescue units, rapid response team (RRT) and fire investigation team (FIT). The IC must not rely on the GA or other agencies detection equipment, if crews are to be committed to a risk area.
End of the incident
The responsibility for the incident should be handed to the GA or their representatives.
When Control have to notify a GA that gas apparatus is involved at an incident the following information has to be included:-
(a) whether the incident is inside or outside premises (this is important as the GA send different teams for inside and outside incidents);
(b) the size of the fire;
(c) whether any injuries have been sustained by members of the public
