Types of Fire Extinguishers
Different types of fire extinguishers are designed to fight different types of fire.
Common Extinguisher Types
The three most common types of fire extinguishers are: air pressurized water, CO2 (carbon dioxide), and dry chemical.
Dry Chemical: Dry chemical fire extinguishers use a fine powder agent (typically monoammonium phosphate for multipurpose versions) to suppress fires. They work by coating the fuel with a layer of dust to separate it from oxygen, interrupting the chemical reaction of the fire, and providing some cooling effect.
They are not ideal for lithium-ion battery fires—they may knock down flames initially but often fail to cool the cells enough to prevent thermal runaway/re-ignition. Use specialized agents like AVD, F-500 EA, or FCL-X instead.
Water: These extinguishers contain water and compressed gas and should only be used on Class A (ordinary combustibles) fires.
Carbon Dioxide (CO2): CO2extinguishers are most effective on Class B and C (liquids and electrical) fires. Since the gas disperses quickly, these extinguishers are only effective from 3 to 8 feet. The carbon dioxide is stored as a compressed liquid in the extinguisher; as it expands, it cools the surrounding air. The cooling will often cause ice to form around the horn where the gas is expelled from the extinguisher.
Other Extinguisher Types
Aqueous Vermiculite Dispersion (AVD):This type of extinguisher uses a vermiculite-based mist (vermiculite mineral particles suspended in water) that cools the fire intensely and forms a protective, heat-resistant barrier around burning cells to encapsulate flames, block oxygen, and stop re-ignition. It is widely regarded as one of the most effective extinguisher types for small-to-medium battery fires; tested under standards like the Dutch Technical Agreement (NTA) 8133 with strong results in real-world demos (e.g., in e-bikes, scooters, or electronics).
F-500 Encapsulator Agents (F-500 EA®): F-500 is a specialized proprietary (Hazard Control Technologies), an fluorine-free, biodegradable encapsulator that forms microscopic micelles to encapsulate flammable electrolytes/fuels, rapidly cool (dropping temperatures dramatically in seconds), interrupt chemical chain reactions, and reduce toxic gases/smoke. It is effective on multi-class fires, including lithium-ion (passes NTA 8133 and other tests), and recognized by NFPA for battery hazards.
FCL-X®: This is a proprietary (Full Circle Lithium), non-toxic, PFAS-free, water-based agent optimized for lithium-ion chemistry. It buffers oxidation reactions, forms non-hazardous salts to limit heat/hydrogen production, provides fast knockdown, and prevents re-ignition with minimal cleanup. Available in various extinguisher sizes (retail to industrial) and has passed rigorous tests like NTA 8133.
Hydrogel-Based Agents: Hydrogel agents are thermoresponsive gel formulations (often PFAS-free) that form a sticky, insulating layer on hot surfaces for superior cooling, oxygen isolation, and combustion inhibition. They adhere well to battery packs, excel at halting thermal runaway escalation, and are promoted as next-generation, eco-friendly solutions for lithium fires (used in portable extinguishers and systems).
Halon: The bromochlorodifluoromethane (Halon 1211) fire extinguisher has an agent that is similar to carbon dioxide in that it is suitable for cold weather installation and leaves no residue. Halon fire extinguishers have been phased out due to ozone-depleting substances. Production and new imports of halon (e.g., Halon 1211, 1301, 2402) have been banned since January 1, 1994, in the US and most countries worldwide—no new halon is manufactured.
In the US, full decommissioning is gradual, relying on recycled supplies. Old halon extinguishers (e.g., used in boats, vehicles, or homes/businesses), are still usable until they need service or expire—but they should be replaced with modern alternatives for environmental reasons.
Knowledge Check Choose the best answer for the question.
5-7. Which of the following extinguishers is usually rated for multiple purpose use?
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