Walk through almost any commercial building in Texas, and you will find red ABC dry chemical extinguishers on the wall. For decades, they have been the default choice because they cover the three most common fire classes in a single unit. But the hazards inside those buildings have changed. Forklifts, power tools, e-bikes, scissor lifts, UPS systems, and battery energy storage have filled warehouses, shops, and offices with lithium-ion cells, and those cells fail in a way ABC powder was never designed to handle.

FCL-X is a newer, water-based extinguishing agent developed by Full Circle Lithium specifically for lithium-ion battery fires. This guide compares FCL-X and ABC extinguishers side by side, explains where each one belongs, and shows how FireTron helps Texas facilities build a portable extinguisher plan that covers both everyday fires and battery hazards.

TLDR:

• ABC dry chemical extinguishers smother flames but do not cool a lithium-ion cell, so a battery can keep heating and reignite after the powder settles.
• FCL-X is a water-based, PFAS-free agent built for lithium-ion battery fires. It cools the battery and coats it to help keep the reaction from restarting.
• FCL-X earned UL Class A component recognition in 2025. No portable extinguisher currently holds a dedicated UL fire class rating for lithium-ion battery fires.
• Most facilities need both: ABC (or clean agent near electronics) for general coverage, plus FCL-X at charging stations, battery storage, and equipment bays.
• FCL-X is not Class C rated. Keep a clean agent or CO2 extinguishers near energized electrical equipment.

Why Lithium-Ion Battery Fires Need a Different Extinguisher

A lithium-ion battery fire is driven by thermal runaway. When a cell is damaged, overcharged, or defective, it heats up, and that heat triggers chemical reactions inside the cell that create even more heat. The failing cell can release flammable and toxic gases and pass its heat to the cells around it, so the fire spreads through the pack one cell at a time.

That changes what an extinguisher has to do. Knocking down the visible flames is not enough. The agent has to pull heat out of the battery fast enough to stop the chain reaction, or the pack can reignite minutes, hours, or even days later. For a deeper look at how thermal runaway works and what FCL-X is, see our guide: [What Is FCL-X? A Commercial Fire Safety Guide to Lithium-Ion Battery Protection].

How ABC Dry Chemical Extinguishers Work

ABC extinguishers discharge monoammonium phosphate, a fine yellow powder. It works by coating burning surfaces and interrupting the chemical reaction of the fire. That makes it effective on Class A (ordinary combustibles), Class B (flammable liquids), and Class C (energized electrical) fires, which is why it is the most common commercial extinguisher in the country.

ABC units still have an important place in your facility. They are affordable, widely available, easy to service, and they meet NFPA 10 coverage requirements for general hazards in offices, warehouses, and retail spaces. The problem is not that ABC extinguishers are bad. It is that they are being asked to cover a hazard they were not built for.

Where ABC Falls Short on Battery Fires

• Little cooling effect: The powder smothers flames but absorbs very little heat, so the inside of a failing battery can stay hot enough to keep the reaction going.
• No protection for neighboring cells: Heat keeps moving from cell to cell under the powder, which lets the failure spread through the pack.
• Re-ignition risk: Once the powder settles and oxygen returns, a battery that is still in thermal runaway can flare back up.
• Corrosive cleanup: ABC powder absorbs moisture and becomes acidic, which damages electronics, chargers, and nearby equipment.

How FCL-X Extinguishers Work

FCL-X is a proprietary, water-based agent made for the way lithium-ion batteries actually fail. Instead of only smothering the flames, it is designed to attack the heat that drives thermal runaway.

• Cooling: The water-based agent absorbs heat from the battery and works to bring the cells below the temperature needed to sustain the reaction.
• Encapsulation: The agent coats the damaged cells to help block oxygen and limit re-ignition.
• Cleaner chemistry: Full Circle Lithium reports third-party testing showing total fluorine below 1 ppm, and describes the agent as PFAS-free and low-toxicity. That matters for a building’s occupants, its responders, and its cleanup.

In July 2025, FCL-X received UL Solutions component recognition as a Class A water-based fire extinguishing agent for the United States and Canada. Full Circle Lithium has said it plans to pursue additional certifications for lithium-ion battery applications. FCL-X extinguishers are available in 1-liter, 2-liter, and 3-liter sizes, along with a 20-ounce aerosol can for small spaces and vehicles.

Because UL does not currently have a dedicated fire class rating for lithium-ion battery fires, no portable extinguisher on the market carries one. That is why it helps to work with a fire protection provider who understands both the product and the codes when you add FCL-X to your facility.

FCL-X vs ABC Fire Extinguisher: Side-by-Side Comparison

Which Extinguisher Does Your Facility Need?

For most commercial facilities, the answer is not FCL-X or ABC. It is FCL-X and ABC, each placed where it does the most good. Here is how that breaks down by hazard:

Electrical equipment deserves special attention. FCL-X is water-based and is not rated for energized electrical fires, so it should not replace the Class C protection around panels, switchgear, and server racks. For those areas, see our guide to the best fire extinguishers for electrical fires and server rooms.

Adding FCL-X to Your Facility the Right Way

Adding FCL-X without a plan can leave gaps, such as units mounted far from where batteries actually charge or no coverage for the combustibles around a charging station. A strong implementation includes:

• A hazard assessment: Identify every place where lithium-ion batteries are charged, stored, used, or collected for disposal.
• Strategic placement: Mount FCL-X units where staff can reach them quickly from battery hazards without crossing the fire. Our guide on [where businesses should place FCL-X fire extinguishers] covers this in detail.
• Code-compliant general coverage: Keep ABC or clean agent extinguishers in place to meet NFPA 10 travel distance, mounting height, and signage requirements.
• Training: Make sure staff know which extinguisher to grab for a battery fire, when to evacuate, and to call 911 even if the fire appears to be out.
• Inspection and service: Include FCL-X units in your monthly checks and annual service so every extinguisher stays ready and documented. See our fire extinguisher service requirements for Texas facilities.

Portable extinguishers are a first line of defense. Facilities with large battery storage or energy storage systems should also evaluate detection and automatic suppression. Learn more about lithium-ion battery fire protection for commercial facilities.

Frequently Asked Questions

Can an ABC fire extinguisher put out a lithium-ion battery fire?

An ABC extinguisher can knock down the flames on and around a battery, but it does little to cool the cells inside. A battery in thermal runaway can keep heating under the powder and reignite. For areas with lithium-ion batteries, a purpose-built agent like FCL-X is the better choice.

Is FCL-X UL listed?

In July 2025, the FCL-X agent received UL Solutions component recognition for Class A fires as a water-based extinguishing agent. There is currently no dedicated UL fire class rating for lithium-ion battery fires, and Full Circle Lithium has said it plans to pursue additional battery-related certifications.

Can FCL-X replace my ABC extinguishers?

Not entirely. ABC extinguishers still provide the broad Class A, B, and C coverage required by NFPA 10 for most buildings. FCL-X should be added where lithium-ion battery hazards exist, not used as a one-for-one replacement.

Is FCL-X safe to use on electrical equipment?

FCL-X is water-based and is not Class C rated, so it should not be your primary extinguisher for energized electrical equipment. Use clean agent or CO2 extinguishers around panels, server racks, and switchgear, and de-energize equipment first when it is safe to do so.

Where should FCL-X extinguishers be placed?

Place them near battery charging stations, battery storage and recycling areas, equipment and vehicle bays, and anywhere staff charges e-bikes, scooters, or power tools. A fire protection provider can map placement to your floor plan and existing extinguisher coverage.

Get FCL-X and Lithium-Ion Battery Fire Protection from FireTron

FireTron has provided commercial fire protection and life safety services across Texas since 1990. We help facilities in Houston, Austin, Dallas-Fort Worth, Corpus Christi, College Station, and Victoria assess battery hazards, add FCL-X where it belongs, and keep every extinguisher in the building inspected and compliant through our [fire extinguisher services].

If your facility has added forklifts, charging stations, battery storage, or other lithium-ion equipment, now is the time to review your extinguisher plan. Contact FireTron today to schedule an assessment.