SOG 31-33 Emergency Response Guidelines for LPG and NG Handling

Propane/Natural Gas Emergencies

• Full protective clothing and SCBA is required for all propane/natural gas firefighting and leak control operations
• Apparatus placement should stop short of the area, preferably uphill and upwind
• Determine the hazardous area, considering that LPG is heavier than air and settles in low-lying areas

Incident Command

• Establish HOT, WARM, and COLD zones
• Formulate a plan of action based on the initial size-up
• Secure and shut off NG and LPG to the building or residence
• Compare resources available versus the level required to effectively and safely handle the problem

Safety Precautions

• Avoid a full commitment of personnel and apparatus until a complete size-up has been made
• Keep all bystanders at least 2000 feet away from the hazardous area
• Remove all ignition sources in the hazardous area
• Keep clear of tank ends if fire is impinging on the tank

LPG Fires

• If whistling from the pressure relief valve becomes progressively louder, evacuate the area, as an explosion is imminent
• Imminent explosion evacuation will be signaled by continuous blasts of airhorns and/or high-low electronic siren

LP Gas Properties

• Belongs to the family of chemical compounds known as Hydrocarbons
• LP Gas is highly flammable
• Tasteless, colorless, odorless

Natural Gas Properties

• Combustible mixture of hydrocarbon gases that is highly flammable
• Non-toxic, but has inhalation hazard; will displace oxygen and act as an asphyxiant
• Tasteless, colorless, odorless; odorant added - similar to heavy skunk odor
• Lighter than air; if natural gas escapes into the atmosphere, it dissipates rapidly unless trapped

Leak Control and Mitigation

• Establish adequate water supply
• Secure ignition sources
• Approach leak from upwind
• Use fog streams to protect exposures

Building Collapse

• Initial response: consider safety hazards prior to arrival on scene based on dispatch information
• Park apparatus in a safe location and perform a thorough scene size-up and identification of possible hazards

Void Detection

• Voids may be formed for various reasons and in various forms
• During the search phase, survivors are most likely to be found inside voids

Search and Rescue

• A systematic approach to dealing with building collapse will enable the Incident Commander to increase efficiency and reduce injury to both rescue personnel and civilians
• The initial stages can be broken down into two basic functions: Reconnaissance and Immediate Rescue

Scene Organization and Management

• Working within the incident command system is essential to a successful operation
• A unified command should be established
• The following checklist may assist: shutting down utilities, ensuring structural integrity, and establishing a contingency plan

Nuclear, Biological, and Chemical (NBC) Emergencies

• Personal safety is a high priority when responding to a NBC event
• Decontamination is a primary concern for NBC terrorism
• Patients are not to be placed in rescue apparatus for transport prior to completing decontamination measures

Biological Emergencies

• Acts of biological contamination are not likely to be immediately detectable, and may not be evident until 72 hours post-exposure
• Common signs and symptoms that may occur from three hours to six days after exposure include flu-like symptoms, fever, weakness, headache, nausea, vomiting, cough, diarrhea, and chills

Chemical Emergencies

• The use of chemical weapons, unlike biologic agents, will have immediate effects ranging from seconds after exposure until the first few hours

• Chemical agents may be in the form of a solid, liquid, or gas### Properties of LP Gas

• Ethyl mercaptan is added to LP gas to give it an odor.

• LP gas can be a liquid or gas, and it will be a gas at ambient temperature.

• It is usually stored and transported as a liquid under pressure.

Handling and Safety

• When LP gas is stored or transported, it can expand from liquid to gas in a 270:1 ratio.
• Heat can cause the product to expand and increase container pressure, leading to a boiling liquid expanding vapor explosion (BLEVE) if left un-cooled.
• LP gas is non-toxic, but it can displace oxygen and act as an asphyxiant, making it an inhalation hazard.

Physical Characteristics

• Propane vapor is 1.5 times heavier than air and will settle in low areas, becoming concentrated.
• The ignition temperature of LP gas is between 920°F and 1120°F.
• The flammable range of LP gas is between 2.1% and 9.5%.

Emergency Response

• The Immediately Dangerous to Life or Health (IDLH) concentration of LP gas is 2000 PPM.
• When responding to an LP gas leak, establish an adequate water supply, secure ignition sources, and approach the leak from uphill and upwind.
• Use fog streams to protect exposures and direct the vapor cloud.
• If possible, use heavy fog streams to dissipate the vapors without disturbing the liquid.

Mitigation and Control

• Consult with the driver of the vehicle or plant personnel to locate the valve and shut off the fuel supply if possible.
• Close the valve if deemed safe to do so, but follow the "Two In - Two Out" rule and wear full structural firefighting gear with SCBA.
• Use hose lines with a fog pattern to create a safe zone and protect responders while working in the hot zone.
• Do not use tools that may spark, and note that if the leak cannot be stopped by turning the valve to the off position, responders will immediately return to the cold zone.

Fire Response

• Special Operations response is required for LP gas fires.
• Establish a sufficient and reliable water supply, and use hose streams to protect the container from overheating and protect exposures from radiant and convected heat.
• Approach from uphill and upwind, and direct streams to the area above the liquid level.
• If the tank is burning, fire streams must be used to cool the vapor area of the tank.
• Consult with the driver of the vehicle or plant personnel to locate the valve and shut off the fuel supply if possible.
• Do not extinguish tank or cylinder fires unless the shut off can be effected.