LPG/NG Incident Response

• This Standard Operating Guideline (SOG) exists to establish the Palm Beach County Fire Rescue's response, notification, monitoring, and mitigation procedures for incidents involving Liquefied Petroleum and Natural Gas (LPG/NG).
• The SOG applies to all Emergency Operations personnel.

General Procedures

• Refer to the Emergency Response Guidebook 2016 version, pages 20-25 and Orange Guide pages 115-116 for general guidance.
• LPG/NG incidents can escalate into major emergencies involving fire, explosion, collapse, or large-scale evacuation.
• LPG/NG can spread rapidly and create an Immediately Dangerous to Life or Health (IDLH) atmosphere.
• Responders must know the characteristics of LPG/NG, where to look for them, how to monitor, and how to anticipate dispersion patterns.

Natural Gas Characteristics

• Natural Gas is also known as Methane.
• Natural Gas is lighter than air, causing it to rise.
• Natural Gas will fill a room or attic from the ceiling or roof down, respectively.
• Exterior leaks of Natural Gas typically disperse quickly as they rise.
• When using the Drager X-am 2500 4-Gas monitor, ensure it is positioned at the correct height to detect Natural Gas.
• Natural Gas has a Lower Explosive Limit (LEL) range from 5.3% to 14% by volume.
• Natural Gas is naturally colorless and odorless; mercaptan is added to give it a rotten egg odor.
  • Larger diameter piping (18” and above) does NOT have mercaptan added.
• Natural Gas is commonly supplied via underground piping through a gas meter.
• The presence of a gas meter indicates Natural Gas is supplied via underground piping from an off-site location.
• Gas meters are often marked with yellow markings or labels and are low to the ground.
• Underground piping for Natural Gas can range from ½" to 30" and larger. Palm Beach County has some locations with very large non-odorized Natural Gas piping.
  • Examples include a 24" Natural Gas pipeline along the turnpike exerting 975psi and a 24" pipeline running from the Port of Palm Beach to the West County Energy Center.
• Common Natural Gas pipe sizes along non-residential roadways range from 1" to 4".
• Natural Gas in underground piping may be supplied from both directions.
• Common Natural Gas pipe sizes between residential sidewalks and homes are typically 1½" to ".

Liquefied Petroleum Gas Characteristics

• Liquefied Petroleum Gas (LPG) is also known as Propane.
• LPG is heavier than air.
• LPG will fill a room or attic from the floor or bottom up, respectively.
• An outside leak of LPG will stay low and typically NOT disperse quickly.
• When using the Drager X-am 2500 4-Gas monitor, ensure it is at the correct height to detect LPG.
• LPG has a LEL range from 2.1% to 9.5% by volume.
• LPG and Natural Gas are colorless and odorless, with mercaptan added for a sulfur/rotten egg smell.
• LPG can be supplied from underground piping or storage tanks.

LPG Storage Tanks

• Barbecue grills typically use 20lb Portable LPG tanks.
• Forklifts typically use 33lb Portable LPG tanks.
• Commercial properties may have 100-420lb Standup LPG tanks.
• Residential homes may have 500-1,000lb Underground LPG tanks.
• The Herman W. Brice Fire Rescue Complex has a 30,000lb Aboveground LPG tank.

Investigation of LPG/NG Leak

• Approach upwind, when possible.
• Avoid introducing ignition sources.
• All Fire Rescue personnel shall wear Bunker gear and SCBA for known or suspected LPG/NG leaks.

First Arriving Unit Responsibilities

• The first arriving unit shall:
  • Establish Incident Command.
  • Give an Arrival Report.
  • Interview witnesses and gather information.
  • Evacuate all occupants.
  • Establish an Initial Isolation Zone.
  • Use the Drager X-am 2500 4-Gas monitor.
  • Normal atmospheric conditions: Oxygen at 21% and LEL at 0%.

Confirmed LPG/NG Leak

• All actions and responsibilities are in addition to the Investigation phase.
• The Incident Commander shall:
  • Request a Battalion Chief and EMS Captain to respond.
  • Ensure personnel accountability.
  • Establish Control Zones.
    • The Hot Zone starts when the Drager X-am 2500 4-Gas monitor gets a LEL reading above zero.
  • Ensure continued monitoring with Drager X-am 2500 4-Gas monitor.
  • Ensure the two-in/two-out rule is followed for any entry into a Hot Zone.
  • Ensure a Water Supply is established.
  • Ensure a charged 1¼ hose line (at a minimum), with a fog nozzle, is in place.
  • Secure gas meter or LP tank and apply Lockout/Tagout device.
  • Request the Communication Center to contact the appropriate LPG/NG company for response.
• After the incident has been properly mitigated, ALL affected areas and exposures SHALL be assessed and monitored with the Drager X-am 2500 4-Gas monitor.

Exterior LPG/NG Leak Responsibilities

• All actions and responsibilities are in addition to the Investigation and Confirmed phases.
• The Incident Commander should consider requesting Special Operations.
• The Incident Commander shall:
  • Assign an Incident Safety Officer.
  • Let any open flame from an uncontrollable LPG/NG source continue to burn.
  • Ensure Exposures are protected.
  • Direct the strategic goals to mitigate the leak or hazard.
    • Immediately COOL LPG tanks with flame impingement to ensure a boiling liquid expanding vapor explosion (BLEVE) does not occur.
      • DO NOT PUT THE FLAME OUT if the LPG source can NOT be controlled.
      • If a pressure relieve valve is activating, cool the Aboveground LPG tank immediately and evacuate the area.
      • Aboveground LPG tanks shall be cooled with at least a 2½ hose line flowing 200pgm.
        • 500gpm is required to cool any 1,000lb or greater aboveground LPG tank with flame impingement.
    • A ½" to ¼” inch polypropylene pipe may be bent and taped with duct tape to stop or reduce the leak.
      • Static electricity is a concern. Every care should be taken to reduce the chance of generating a spark.
      • The area around a leak should be sprayed with water, on a wide fog pattern, to reduce the chance of static build up, but avoid drenching the area.
      • Do NOT use a hacksaw to cut a polypropylene pipe; use PVC pipe cutters.

Interior LPG/NG Leak Responsibilities

• The below are in addition to the Exterior LPG/NG Leak Responsibilities
• The Incident Commander should consider requesting a Fire Investigator.
• The Incident Commander shall:
  • Assign an Incident Safety Officer.
  • Ensure Benchmarks are performed and communicated.
  • Ensure Primary and Secondary Searches are completed.
  • Ensure natural ventilation of the structure until Drager X-am 2500 4-Gas monitor readings are below 2% LEL.

Special Operations Team

• Upon arrival the Special Operations Captain shall report to the Incident Commander.
• Offensive LPG/NG mode
  • Special Operations may take the following Offensive measures: - Grounding - Plugging - Cutting - Clamping - Squeezing - Flaring off (Burn Off)
• Defensive LPG/NG mode
  • Special Operations may take the following Defensive measures: - Wait for the LPG/NG company to arrive. - Confer with the LPG/NG company to determine the mitigation strategy.

Documentation

• Document the incident according to Incident Reporting (PPM FR-M-201) including:
  • Drager X-am 2500 4-Gas monitor readings before, during and after mitigation.
  • LPG/NG company technician information.
  • Who the scene was turned over to.
• All units MUST write a “UNIT” Narrative into the applicable NFIRS program.