Universal Steps: Responding to Alternative Fuel Vehicle Incidents

BY ROMMIE L. DUCKWORTH

On February 15, 2024, the Los Angeles City (CA) Fire Department (LAFD) was dispatched to a semi-truck engulfed in flames. Not immediately evident was the fact that this semi didn’t run on diesel fuel. It was fueled by twin 100-gallon tanks of compressed natural gas (CNG). As recounted by LAFD officials, the initial firefighting efforts were routine, with water applied to extinguish the flames. However, disaster struck a mere six minutes into the operation when one of the CNG cylinders detonated with tremendous force, unleashing a fireball into the sky. Nine firefighters were hospitalized, two in critical condition.¹

• Responding to Alternative Fuel Vehicles: Knowing CNG Is Not Enough
• Commercial CNG Vehicles: A Whole New Danger for Responders

Besides hybrid and all-electric vehicles, alternative fuels used in cars, trucks, and buses include alcohol blends, compressed and liquefied petroleum gasses, hydrogen, and more.² As a result, we need to update how we think about motor vehicle incident response. With a wide variety of fuels powering vehicles that travel American roadways, we need to adopt universal steps to help identify and manage threats from virtually any fuel source at any vehicle-related incident.

Universal Steps for Motor Vehicle Collisions

Regardless of the fuel they use, all vehicles involved in collisions can be evaluated using the following universal steps:

1. Approach.
2. Identify.
3. Immobilize.
4. Disable.
5. Access.^3,4

Alternative fuel vehicles (AFVs) do not automatically become “ticking time bombs” just because they are involved in a minor fender bender. However, during motor vehicle incidents, safety systems may fail, and fuel containers and transmission lines may be compromised, leak, or rupture. Although the sight of fire or a victim calling for help may trigger your instinct to rush in, the way to be successful at motor vehicle incidents is to work in a coordinated method using universal steps that prioritize life safety, incident stabilization, and property conservation.

1. Approach

Complacency is the enemy. Things go wrong on “routine” calls. The goal of the universal steps is for no firefighters, company officers, or chiefs to find themselves backpedaling out of a dangerous situation. We can use a conversation about alternative fuel as an opportunity to make sure we’re not complacent at any vehicle-related incident.

For example, you may assume that you will be able to smell any flammable gas as you approach; however, liquefied natural gas (LNG) cannot be odorized. As a result, you must look for other indicators as you approach.

Likewise, you may assume if there were a fire you would see it, but this may not be the case with hydrogen or high-alcohol blend fuels. PPE should include turnout gear with SCBA at least at the ready. In addition to protection from physical hazards, you may find yourself suddenly in or near heat or flame.

Initial apparatus placement should be close enough to allow access but far enough to account for fire or explosion hazards and to protect a working area for rescue, EMS, hazmat, or firefighting operations. A “safe zone” of at least 20 to 50 feet will allow proper fire and collision protection of the work area.^4,5

When approaching and protecting an incident involving AFVs, it is important to place apparatus uphill and upwind when possible. Make your approach from a 450 angle rather than straight on or from the side. Vehicles may begin to move forward or backward unexpectedly and shock-absorbing bumpers, drive shafts, and struts can rupture and become forward- or rear-facing projectiles during a fire.⁴ In addition, AFVs may have pressure- and temperature-relief devices that vent flammable gases to the rear of the vehicle.^4,5

Traffic incident management is a consideration at any motor vehicle collision, but some AFVs will need wider margins of safety between work areas and areas safe for the flow of civilian traffic. Do not use flares or place any other source of ignition in proximity to vehicles. While no scene is perfect, firefighters should be 100% clear as to the areas safe for operations and the areas with hazards, whether those hazards are leaking fuels or fluids, down power lines, distracted drivers in nearby lanes, or any other type of danger.

Scanning the area and vehicles with a thermal imaging camera and, if possible, a combustible gas meter can provide critical information you would otherwise miss. In addition to being able to identify invisible and nonodored flammable gases leaking from AFVs, you will be able to identify heat signatures to see how many people were seated in the vehicle and what parts of the vehicle may be overheating next to or involving vehicle fuels or fuel storage. For example, you may identify heat damage to a drive motor on an electric vehicle next to the HV battery pack, a fire involving hydrogen, or an alcohol fuel blend that may be very difficult to see during the day.

2. Identify

As apparatus get into position and firefighters approach, size-up continues. Identify immediate life threats and high-priority or emergency rescues or extrications as soon as possible. These may be obvious as you approach, or you may need to identify them by talking to vehicle occupants, bystanders, or other responders. Officers should routinely perform a 360° assessment at a motor vehicle incident just as they would a fire.

In addition to original equipment manufacturers (OEMs) that produce AFVs, conversion kits enable virtually any vehicle to use alternative fuels, including cars, trucks, commercial vehicles, municipal vehicles, farm vehicles, and more.⁶ Virtually all vehicle OEMs from Chevy to Volkswagen, Kia to Ferrari, produce hybrid and all-electric light vehicles including sports cars, pickups, sedans, and SUVs.⁷

The same is true for practically every major heavy vehicle manufacturer, from Freightliner to Mack.⁸ Some AFVs, primarily electric and hybrid, can be identified directly by their makers, as these manufacturers only make electrics. (See “Major Manufacturers Specializing Only in Hybrid or All-Electric Vehicles.”) Many familiar OEMS, including Dodge, Ford, Toyota, and Honda, produce nonelectric AFVs, as do OEMs of heavy vehicles such as transit vehicles, school buses, tractors, street-sweepers, long-haul trucks, and more.⁷ (See “Major Manufacturers of Alternative Fuel Light Vehicles.”)

A variety of laws, recommendations, and regulations require converted or OEM-built AFVs to have a prominent decal or other marking that can be clearly read from a distance, indicating what type of alternative fuel the vehicle uses. For example, most vehicles that use compressed gas fuels must have a diamond-shaped label placed at the rear of the cab or the rear of the vehicle and possibly at the fuel port indicating what kind of compressed gas is used: compressed natural gas (CNG), liquefied petroleum gas (LPG), LNG, or hydrogen.³ Of course, these badges may be removed, destroyed, or hidden from view.

Besides reading the vehicle type and badging from a distance, make it a habit to ask the vehicle operator if the vehicle uses a special fuel or has any other hazard you should know about. When you get closer to the vehicle, look at its features such as the fuel or charging port, the instrument cluster, the motor under the hood, the fuel tanks or battery packs if visible, and the radiator or exhaust (or lack thereof) to identify fuel types and hazards. In addition, some extrication reference apps and advanced automatic crash notification systems (AACN), such as OnStar, can help identify AFVs.⁹

Just as gasoline or diesel fuel on the roadway can easily be mistaken for oil or coolant, leaking CNG, LPG, or LNG may initially be mistaken for steaming coolant or airbag “smoke.”

The Department of Transportation Emergency Response Guidebook (ERG) can give guidance on the immediate hazards, public safety considerations, and emergency response recommendations presented by alternative fuels. However, this guidance is for quick reference as you get started and does not present a complete guide to strategy and tactics for alternative fuel incidents.

Where possible, the incident commander (IC) should be paying attention to the incident and should assign an assistant, aide, or firefighter to use the ERG, along with the appropriate manufacturer’s emergency response guide or rescue sheet available from the NFPA at bit.ly/3y7n35V.

In some departments, units on scene relay vehicle information to their dispatch center, which maintains the guides and references used to provide this information. This way the IC can maintain situational awareness, and the assistant or dispatcher can convey relevant information so the IC can make faster, more effective decisions. It is unrealistic to expect one person to simultaneously consult in-depth reference materials, maintain situational awareness, and make and effectively communicate command decisions.

3. Immobilize

It can be easy to assume that any vehicle not in motion is already immobilized. You never want to make this mistake with any vehicle, especially AFVs. Place simple wheel chocks for any vehicle that could roll. For example, a vehicle positioned head-on into a utility pole may not need chocks because it is already blocked, but a vehicle in the middle of an intersection would.

Next, if possible, confirm that the vehicle is in park or neutral and the parking brake is engaged. Look at each vehicle and ask, “Is this properly immobilized?” All vehicles should be choked/blocked, in neutral, and brake on before operations proceed. If you’re placing cribbing, struts, or rescue air bags for further stabilization, be careful not to crush, pinch, or compromise the high-voltage cables, fuel lines, supplemental restraint systems (SRS), and vent ports that often run through vehicle rocker panels, posts, and roof rails.¹⁰

4. Disable

Shut down the vehicle motor using the ignition key, start/stop button, or key fob. If possible, move key fobs to a distance of at least 20 feet from the vehicle to help prevent reactivation. Position seats, adjust the steering wheel, unlock all doors, open windows, and operate any electronics in the vehicle that will help with access for victim care, extrication, and fire suppression.¹¹

Deenergizing the vehicle, regardless of fuel type, begins with disabling the 12-volt power source. In virtually every vehicle you will encounter, disabling the 12-volt battery will begin to shut off the relays, fuel pumps, and solenoids to supply the vehicle’s fuel and energy. Note that sometimes more than one 12-volt system may be present, or the vehicle may use a 24-volt system. If any one of these systems needs to be shut down or disconnected, they all need to be shut down or disconnected.¹⁰

Of course, in a collision, systems don’t always work correctly. Don’t assume that removing the key fob or disabling the 12-volt battery will solve all problems. Still, this is just about always the place to start. Often, deenergizing the 12-volt system will also begin a discharge of any electricity stored in capacitors, taking approximately 2 to 10 minutes to complete.¹⁰ Some vehicles will automatically shut down the high-voltage system if a crash is detected or air bags are activated.¹⁰ However, high-voltage batteries will retain their charge. Do not uncover or contact any high-voltage battery system, orange cables, or connections.¹⁰

Battery placement and 12-volt disconnects vary from vehicle to vehicle, with many being tucked away under the hood near the firewall, in the wheel well, or in the trunk area with plastic covers that may not clearly indicate the 12-volt battery access.¹⁰ The manufacturer’s rescue sheet will identify firefighter cut or disconnect areas and may be located virtually anywhere, including behind the rearview mirror. If possible, disconnect or cut the negative battery cable first.¹⁰

In some situations, it may be necessary to use a high-voltage disconnect to shut down the HV system completely. These can be called master switch, emergency shut down, emergency power off, firefighter disconnect, or service disconnect.¹⁰ These will be identified in the manufacturer’s response guides and rescue sheets.¹⁰ In some commercial vehicles, these may be the only way to shut down the HV system entirely.³ If possible, check the instrument cluster and exterior lights on the vehicle to help confirm that low- and high-voltage systems have been shut down. Again, remember that batteries and solar panels are virtually always energized.

For vehicles powered by compressed gases, tanks in passenger vehicles and pickup trucks are typically found either where the gasoline or diesel fuel tanks would be located, while tanks in commercial vehicles are likely positioned behind the cab or in the rear of the vehicle, on the roof, or as saddle tanks.¹⁰ If the vehicle is fueling or charging and is safe, disconnect at the fueling/charging port and shut down the connection if necessary.^3,4

5. Access

When rapid or emergency victim access and extrication are required, the recommendations for the approach, identify, immobilize, and disable steps may need to occur simultaneously with victim care and rescue. Like many aspects of firefighting, this is a calculated risk and should not be taken lightly.

If emergency access is not required, it may be best for you to make contact with the victims but leave them in place until the vehicle and surrounding work area are safe. When it is time to remove or assist the victims, look for the easiest or best exit. It can be easy to be distracted by opportunities to practice extrication techniques when other doors or vehicle exits are available. As with forcible entry, always “try before you pry.”

If extrication is required on an AFV, it is strongly recommended that you have access to the NFPA AFV Manufacturer’s Response Guides to identify the locations of important areas to avoid cutting or crushing, such as the center console, rocker panels, posts, and roof rails that may contain fuel lines, high-voltage cables, or supplemental restraint systems.¹⁰ Firefighters or EMS personnel making contact with the victim should also look for marked cut or no-cut areas inside the vehicle. It may also be appropriate to remove interior plastic and trim to expose areas to look for extrication hazards and opportunities. Additional areas to avoid cutting, crushing, or displacing during extrication include the fuel or charging port, fuel tanks or batteries, orange HV cables, and fuel lines.¹⁰

Ongoing Universal Steps

Just as size-up is an ongoing process at any incident, the IC or designee should continue to check that all universal steps of approach, identify, immobilize, disable, and access have been addressed and communicated as the situation evolves. For example, during the incident, firefighters may be unable to complete some steps without additional information or resources, new hazards may emerge, or further information may become available. The IC and the firefighters under his command can use the universal steps as a short and simple checklist to ensure critical steps are taken in the right order to be safer and more effective at every motor vehicle collision. The IC may want to review this list and ask, “Have we completed ‘X’?”

Additional Considerations

While you can follow the universal steps at all motor vehicle collisions, you may need to take additional actions to deal with fire suppression, hazardous materials release from spills and leaks, and submerged vehicles. Fire department responsibility may extend to hazard mitigation through towing and storage. When it comes to AFVs, each of these situations carries additional fire department considerations, including the following:

• Fires.
• Spills and leaks.
• Submerged vehicles.
• Towing and storage.

Fires

Like modern structures, modern vehicles carry a much greater fuel load than classic vehicles. Booster lines may not provide adequate water to extinguish a high fire load of burning plastic and vehicle fuels or prevent thermal runaway for the high-voltage battery cells in electric vehicles.⁴ The many volatile organic compounds and other toxic gases emitted during vehicle fires make SCBA essential for firefighters.⁴

The current ERG can provide a rough guide for initial actions, but specific strategies and tactics identified in manufacturers’ emergency response guides may rely on other firefighting skills. For example, when you’re dealing with AFVs, using flammable gases such as CNG, LPG, or hydrogen, the strategy is to shut off the leak, if possible, rather than extinguish any fire.

Extinguishing burning gases removes the heat and flame hazards, but flammable gases that continue to leak pose a risk of ignition and explosion.¹² If it is impossible to shut off the fuel, you must identify whether it is CNG, LPG, LNG, or hydrogen. If the fuel is LPG (propane), cool and protect the tank and exposures. However, if the fuel is CNG, cryogenic LNG, or hydrogen, do not apply water directly to the tank, as it may result in the tank rupturing. Instead, operate from a safe distance and cool and protect exposures.¹³

AFV compressed gas cylinders have different types of relief valves. CNG and hydrogen composite wrap cylinders are fitted with thermally activated pressure relief devices (TPRDs). This is because fire may cause failure of the composite wrap before the pressure in these cylinders increases much.³ Thermally activated pressure relief devices will activate between 220°F and 240°F and, once activated, will slowly vent the entire contents of the cylinder.³ TPRDs do not reset like LPG pressure-relief devices.

LPG cylinders have the same spring-activated pressure-relief devices that firefighters regularly encounter. However, cryogenic LNG cylinders have multiple spring-activated reseating pressure-relief devices—one that activates at 225 psi and another at 350 psi. Each will reset when the pressure drops below approximately 210 psi.³ Since LNG and hydrogen can’t be odorized, combustible gas detectors are installed in vehicles using these fuels.³

Some smaller vehicles fueled by compressed or liquefied gases have safety systems that shut off the solenoid valve when a crash or air bag deployment is detected. Larger vehicles will have a ¼-turn manual valve that must be shut off. Other vehicles, like transit buses, may have a fire suppression system that will activate in the event of a fire.³

Some larger AFVs have sensors to detect a fire or overheating condition, activating an audible alarm in the operator’s compartment and discharging an ammonium phosphate extinguishing agent in the overheating area.¹⁰ Onboard AFV fire suppression systems may also be manually activated.¹⁰ Remember that high alcohol blend fuels and hydrogen gas may burn clear and be extremely difficult to identify without a thermal imaging camera.

Thermal runaway in the lithium-ion batteries used by electric AFVs is a critical concern. Thermal runaway occurs when a lithium-ion battery overheats, leading to a self-sustaining reaction where a battery that is hot or on fire heats up an adjacent battery. Even if the first battery is extinguished, once a lithium-ion battery is overheated, the thermal runaway process begins, even if it takes hours to days to heat up enough to ignite, continuing the thermal runaway process. During thermal runaway, lithium-ion batteries release toxic and flammable gases.¹⁴

It is important to never apply small volumes of water to a battery for reasons similar to why it is essential to not apply small volumes of water to an acid. Rather than a large volume of water cooling and diluting, a small amount of water applied to batteries may accelerate reactions and release hydrogen and oxygen gases, increasing fire and explosion hazards.

For electric vehicles, in the unlikely event that the battery is directly damaged, do not contact the battery or any leaking liquids, gels, or gases. Expect that other safety systems have failed and prepare for leaks and fire. If a battery fire occurs or is expected, firefighters should maintain a minimum 20-foot safety perimeter around the vehicle and wear full firefighting gear with SCBA.⁴

Overheating high-voltage batteries may also vent hydrogen-fluoride gas, emitting large flames due to the lithium-ion thermal runaway process. While ABC fire extinguishers may be appropriate to extinguish small or isolated vehicle fires, any fire involving or adjacent to an AFV battery or fuel tank should be approached with a minimum of 11⁄2-inch hoseline with a significant water supply of 1,000 to 5,000 gallons or more.⁴ Extinguishing efforts should be focused on individual high-voltage battery packs and be guided by observations from a thermal imaging camera for maximum effectiveness.

Prepare for extended operations if a battery pack fire is expected or occurs. The fire risk due to thermal runaway may continue for days after the initial suppression of a damaged lithium-ion battery fire.

Remember, your structural firefighting gear does not protect firefighters from high-voltage shocks. Large amounts of water are an acceptable fire suppression agent for electric vehicles because these systems do not use a high voltage path to ground. However, non-high-voltage safe tools should never be used on or around the battery area due to the increased risk of high-voltage electrocution of firefighters.^4,10 In the case of fire in an electric vehicle, high-voltage systems may reenergize as solenoids, and safety systems may melt and fuse together. ^4,10

Spills and Leaks

All fuels that begin leaking are hazardous materials and can be identified and otherwise managed as such. In addition to the methods listed above, alternative fuels can be identified in many of the same ways as any other hazardous material, in some cases including placards and markings and hot zone clues such as vapor clouds and odors.

Not every leak around a high-voltage pack involves battery electrolytes. Some high-voltage batteries have coolant systems that may crack or leak coolant. Of course, a voltage battery system with a failed coolant system is at greater risk for thermal runaway. Follow your regular hazardous materials release containment policies and procedures for leaking fluids. If a rescuer or victim comes in contact with electrolytes or other dangerous substances from AFVs, flush with copious amounts of water unless you’re instructed differently by the emergency response guide.⁴

Carbon monoxide calls related to hybrid or extended-range electric vehicles are not uncommon. If these vehicles are left in an enclosed area in “ready” mode, the internal combustion engines may turn on occasionally to recharge the high-voltage battery, producing and accumulating hazardous levels of carbon monoxide.⁴

Submerged Vehicles

While a vehicle submerged in water presents logistic problems, the universal steps should still be followed to the extent possible. Submerged vehicles still need to be approached, identified, immobilized, disabled, and accessed if possible.

Leaking fuels, fluids, and gases may accumulate in and around a submerged AFV, presenting extreme toxic, flammable, and explosive hazards. Submerged batteries from electric vehicles may bubble as the battery produces hydrogen and oxygen. This may accumulate in the vehicle’s interior, presenting an invisible toxic and explosive hazard that should be vented to avoid ignition.

Towing and Storage

Most AFVs should be removed via flatbed rather than being towed. Towing a hybrid or electric vehicle with traction drive motors engaged may cause them to produce high-voltage electricity and possibly feedback into a damaged electrical system, presenting a significant electrical shock and fire ignition hazard.¹⁰

Hybrid and electric vehicles with a damaged high voltage battery pack or electrical system present a substantial risk of thermal runaway and fire for hours or days. If you identify these hazards, notify the tow operator and storage facility. These vehicles should always be at least 50 feet from any exposure or passenger vehicle.¹⁰

Adapting and Staying Prepared

As the diversity of vehicle fuel sources expands, firefighters must adapt their strategies to “routine” vehicle incidents. The universal steps of approach, identity, immobilize, disable, and access provide a systematic and effective framework for managing incidents involving any fuel type. This approach ensures that you can effectively identify potential hazards, take appropriate safety measures, and execute fire/rescue operations with an emphasis on life safety, incident stabilization, and property conservation.

By adhering to these steps, you can enhance your preparedness and response capabilities, ensuring they remain equipped to handle the evolving landscape of vehicle technologies and fuel sources on American roadways. Now that you know, share it with someone who might not. Put it into practice. Pass it on.

ENDNOTES

1. Prange N., “Violent Vehicle Fire Explosion Causes Severe Injuries to LAFD Firefighters,” Los Angeles Fire Department, February 15, 2024. bit.ly/44nHRSE.

2. Davis S.C., Boundy, R.G. Transportation Energy Data Book: Edition 40, 2022. bit.ly/3y5Bck4.

3. “Alternative fuel vehicle safety training for the fire service,” National Fire Protection Association (NFPA). September 2017. bit.ly/3UgJhJO.

4. Long, R.T., Blum, A.F., Bress, T.J., Cotts, B.R.T., Best Practices for Emergency Response to Incidents Involving Electric Vehicles Battery Hazards: A Report on Full-Scale Testing Results, June 2013. bit.ly/4a5eHbY.

5. Federal Emergency Management Agency (FEMA), U.S. Fire Administration, Traffic Incident Management Systems, FEMA, 2012. bit.ly/3UIxCVR.

6. United States Fire Administration. Fire and EMS: Be Alert for Alternative Fuel Vehicle Conversions. U.S. Fire Administration. March 1, 2023. bit.ly/3xUQk3q.

7. “Alternative Fuels Data Center: Vehicle Search,” United States Department of Energy, December 2023. bit.ly/4doRC7i.

8. Eddy, N., “Heavy-Duty Electric Trucks,” Assembly, December 19, 2022. bit.ly/3Qv38Ei.

9. Advanced Automatic Collision Notification (AACN), “Transportation Safety Advancement Group White Paper,” Institute of Transportation Engineers, April 15, 2019. bit.ly/3UG0JZP.

10. “AFV Emergency Response Guides,” National Fire Protection Association (NFPA), 2024. bit.ly/4a12GUU.

11. Sweet, D., Vehicle Extrication Levels I & II: Principles and Practice, First Edition, Jones & Bartlett Learning, 2012. bit.ly/3UGCxGH.

12. International Association of Fire Chiefs, Fundamentals of Fire Fighter Skills and Hazardous Materials Response, Fourth Edition, Jones & Bartlett Learning, 2019. bit.ly/3JOp7ly.

13. Emergency Response Guidebook 2020, United States Department of Transportation, 2020. bit.ly/3Wu4tix.

14. Pillsworth, T., “The Rules of Engagement for Electric Vehicle Battery Fires,” FireEngineering.com, July 1, 2023. bit.ly/3w6lswA.

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ROMMIE L. DUCKWORTH is a career fire captain and paramedic EMS coordinator for the Ridgefield (CT) Fire Department. A contributing editor for Fire Engineering and JEMS, he has more than 30 years of experience working in career and volunteer fire agencies as a firefighter and rescue coordinator. He has been an adjunct instructor for rescue and extrication programs for the Connecticut Fire Academy. He has a master’s degree in public administration, has a bachelor’s degree in fire service administration, is a graduate of the National Fire Academy’s Executive Fire Officer Program, and is credentialed by the Center for Public Safety Excellence as a fire officer. Duckworth is a frequent speaker at national conferences and a regular contributor to research programs, magazines, and textbooks on fire and emergency service topics. He was an instructor at FDIC International 2024.