Response to Natural Gas Response to Natural Gas Fires and EmergenciesFires and Emergencies

Fire Engineer Scott SandersFire Engineer Scott Sanders

Natural Gas Fires and Natural Gas Fires and EmergenciesEmergencies

Most common gas fuel in USMost common gas fuel in US More than half American homes use More than half American homes use

natural gas for heating and cookingnatural gas for heating and cooking Installed in 60% of new homesInstalled in 60% of new homes Installed in CNG Hybrid VehiclesInstalled in CNG Hybrid Vehicles

Natural GasNatural Gas Methane 70-90%Methane 70-90% EthaneEthane PropanePropane ButaneButane Carbon Dioxide and NitrogenCarbon Dioxide and Nitrogen

Natural Gas Fires and Natural Gas Fires and EmergenciesEmergencies

Natural GasNatural Gas Primary Hazard is “Flammability”Primary Hazard is “Flammability” Non-ToxicNon-Toxic

AsphyxiantAsphyxiant Carbon Monoxide: Toxic Product of In-Complete Carbon Monoxide: Toxic Product of In-Complete

CombustionCombustion

OdorizationOdorization MercaptanMercaptan

1/101/10thth of 1% air of 1% air Identifies gas leak long before dangerous (LEL)Identifies gas leak long before dangerous (LEL)

Prolonged exposure may desensitize individualsProlonged exposure may desensitize individuals

Natural Gas Fires and Natural Gas Fires and EmergenciesEmergencies

Characteristics of Common Gas FuelsCharacteristics of Common Gas FuelsGasGas Vapor DensityVapor Density Ignition PointIgnition Point LELLEL

Natural Gas .55-.65Natural Gas .55-.65 1,000-1,200F1,000-1,200F 4% 4%

PropanePropane 1.6 1.6 842F842F 2.1%2.1%

ButaneButane 2.0 2.0 550F550F 1.6%1.6%

ALL should be considered…. Although NG is ALL should be considered…. Although NG is most prevalent.most prevalent.

Natural Gas Fires and Natural Gas Fires and EmergenciesEmergencies

Distribution SystemsDistribution Systems May be pressurized as high as 1,000 psiMay be pressurized as high as 1,000 psi

Williams PipelineWilliams Pipeline Atlanta Gas Light / ScanaAtlanta Gas Light / Scana

Similar to municipal water systemsSimilar to municipal water systems Consist of street mains that branch to Consist of street mains that branch to

service lines that bring gas to individual service lines that bring gas to individual occupanciesoccupancies

Regulator reduces pressure to ¼ psiRegulator reduces pressure to ¼ psi

Natural Gas HazardsNatural Gas Hazards

Air in a Gas LineAir in a Gas Line Usually occurs after work has been Usually occurs after work has been

done and air hasn’t been properly bled done and air hasn’t been properly bled from line.from line.

Can also enter a gas line as a result of Can also enter a gas line as a result of meter tampering.meter tampering. Results in “Air Slug” Results in “Air Slug”

Natural Gas HazardsNatural Gas Hazards

Combustion ExplosionCombustion Explosion Gas leak confined to an areaGas leak confined to an area

Flammable rangeFlammable range Ignition results in:Ignition results in:

Rapid combustion or explosionRapid combustion or explosion Air doubles in volume for every 459F of increaseAir doubles in volume for every 459F of increase

Air increases pressure inside building 60-110 psiAir increases pressure inside building 60-110 psi Most buildings can’t withstand increase of more than 1 Most buildings can’t withstand increase of more than 1

psi without failingpsi without failing

Natural Gas HazardsNatural Gas Hazards

Loss of OdorLoss of Odor Sand/Dirt can “Scrub” odorant out of gasSand/Dirt can “Scrub” odorant out of gas

Results in virtually undetectable gasResults in virtually undetectable gas Some companies use “Odorless” gas in Some companies use “Odorless” gas in

manufacturing processmanufacturing process Sensitization can result from prolonged Sensitization can result from prolonged

exposure to gas and can result in miss-exposure to gas and can result in miss-identification by firefighters.identification by firefighters. Use Combustible Gas Indicator for NG Use Combustible Gas Indicator for NG

emergenciesemergencies

Natural Gas HazardsNatural Gas Hazards

Regulator FailureRegulator Failure Strong smell of gasStrong smell of gas Hissing soundHissing sound

May lead to over-pressurization of May lead to over-pressurization of appliancesappliances

High Pressure SystemsHigh Pressure Systems Vent pipe: Atmospheric DumpVent pipe: Atmospheric Dump

FD ResponseFD Response Control utilitiesControl utilities Notify Gas SupplierNotify Gas Supplier

Flammable Gas FiresFlammable Gas Fires TacticsTactics

Protect ExposuresProtect Exposures # 1 Consideration after LIFE SAFETY# 1 Consideration after LIFE SAFETY May compound situation due to lack of resourcesMay compound situation due to lack of resources

Shut off gas before extinguishmentShut off gas before extinguishment May re-ignite after extinguishment in presence of ignition May re-ignite after extinguishment in presence of ignition

sourcesource If gas is confined nay result in explosion.If gas is confined nay result in explosion.

Dissipate Leaking GasesDissipate Leaking Gases Ventilate Inside and Disperse OutsideVentilate Inside and Disperse Outside Secure Ignition SourcesSecure Ignition Sources

Allow Gas to “Vent & Burn”Allow Gas to “Vent & Burn” Safest practice if gas cannot be secured prior to Safest practice if gas cannot be secured prior to

extinguishmentextinguishment

Indoor Gas LeaksIndoor Gas Leaks

Understand your enemy and where he lives!!!Understand your enemy and where he lives!!!

Tactics for Indoor Gas LeaksTactics for Indoor Gas Leaks Life Safety (Search)Life Safety (Search) Position Apparatus SafelyPosition Apparatus Safely

Collapse potentialCollapse potential Water Supply?Water Supply?

Determine whether the report of the leak is Determine whether the report of the leak is accurateaccurate

When was the leak noticed?When was the leak noticed? What is involved?What is involved?

Indoor Gas LeaksIndoor Gas Leaks

Search the Area for Trapped Search the Area for Trapped OccupantsOccupants Effects of Gas on OccupantsEffects of Gas on Occupants

Normal Oxygen Concentration = 21%Normal Oxygen Concentration = 21% Loss of motor coordination = 17%Loss of motor coordination = 17% Faulty judgment and fatigue = 10%-14%Faulty judgment and fatigue = 10%-14% Unconsciousness and death = 6%-10%Unconsciousness and death = 6%-10%

Consider Consider SUICIDESUICIDE in some cases! in some cases! Usually from Carbon Monoxide not Natural Usually from Carbon Monoxide not Natural

Gas.Gas.

Indoor Gas LeaksIndoor Gas Leaks

Prevent IgnitionPrevent Ignition Ignition SourcesIgnition Sources

Hand Light?Hand Light? Radio?Radio? SCBA Electronics?SCBA Electronics? Static Electricity?Static Electricity? Building Utilities?Building Utilities?

If it is OFF, Leave it OFF!If it is OFF, Leave it OFF!

VentilateVentilate Natural Ventilation Natural Ventilation

Indoor Gas LeaksIndoor Gas Leaks

Locating the leakLocating the leak Use Combustible Gas Indicator; NOT Use Combustible Gas Indicator; NOT

your NOSE!!your NOSE!! 10% LEL (Methane 5%, Propane 2.1%, 10% LEL (Methane 5%, Propane 2.1%,

Butane 1.6%)Butane 1.6%) Call Gas CompanyCall Gas Company

Always report even if you stopped the leakAlways report even if you stopped the leak Required to re-light pilot lights and repair Required to re-light pilot lights and repair

systemsystem

Indoor Gas LeaksIndoor Gas Leaks

Shut-Off GasShut-Off Gas Order of priority:Order of priority:

Appliance Quarter-Turn ShutoffAppliance Quarter-Turn Shutoff Meter Quarter-Turn WingcockMeter Quarter-Turn Wingcock

NEVER TURN ON A GAS VALVE, NEVER TURN ON A GAS VALVE, SERVICE OR APPLIANCE AFTER IT SERVICE OR APPLIANCE AFTER IT HAS BEEN SHUT OFF!!!! NOTIFY GAS HAS BEEN SHUT OFF!!!! NOTIFY GAS COMPANY!!!!COMPANY!!!!

Indoor Gas LeaksIndoor Gas Leaks

Shut Off and MeterShut Off and Meter

Outdoor Gas LeaksOutdoor Gas Leaks

Tactics and ConsiderationsTactics and Considerations Determine whether a Gas Leak ExistsDetermine whether a Gas Leak Exists

Use MetersUse Meters Consider Sewer Gas (Hydrogen Sulfide)Consider Sewer Gas (Hydrogen Sulfide)

Call the Utility CompanyCall the Utility Company Low Pressure – FD can sometimes handleLow Pressure – FD can sometimes handle

Beware of Static Hazard of Plastic PipeBeware of Static Hazard of Plastic Pipe High Pressure – Requires Special High Pressure – Requires Special

EquipmentEquipment

Outdoor Gas LeaksOutdoor Gas Leaks

Determine Scope of IncidentDetermine Scope of Incident Size of LineSize of Line PressurePressure Gas Escaping into atmosphereGas Escaping into atmosphere Gas Escaping into Storm Drains (Buildings)Gas Escaping into Storm Drains (Buildings) Other utilities affectedOther utilities affected

Define Hazard Area and Protect PublicDefine Hazard Area and Protect Public Evacuation or Protection in Place?Evacuation or Protection in Place?

SummarySummary The single most important piece of The single most important piece of

knowledge that ANY First Responder can knowledge that ANY First Responder can possess is an understanding of what/where possess is an understanding of what/where they are responding to. This will allow they are responding to. This will allow him/her to act in the safest most prudent him/her to act in the safest most prudent manner possible to ensure the safety of manner possible to ensure the safety of his/her crew and the public. The Hazardous his/her crew and the public. The Hazardous Materials Team is always available for Materials Team is always available for consultation and should be used accordingly consultation and should be used accordingly whenever a crew has questions or concerns, whenever a crew has questions or concerns, The #1 priority is “Everyone Goes Home!” The #1 priority is “Everyone Goes Home!”