Fire extinguishers play a crucial role in fire safety, offering a first line of defense against small fires or helping to control them until professional help arrives. While they might not be an everyday topic of conversation, understanding their types, uses, and limitations can be a lifesaver. This article explores the different kinds of fire extinguishers, their applications, pros and cons, and special considerations for marine environments, including pleasure boats.
Fire Basics
You probably remember the “Fire Triangle” from grade school! Fire is a chemical reaction that requires three components to be sustained: Oxygen, Heat, and Fuel. Remove any one of these, and the fire goes out.
Fire extinguishers are designed to remove one of these components. It’s important to understand the various types of fire extinguishers and what types of fires they are designed to address.
The Types of Fires
Fires are grouped into five Classes, primarily based on the Fuel Source.
- Class A: Ordinary combustibles like wood, paper, cloth, upholstery, and boat fiberglass.
- Class B: Flammable liquids and gases like gasoline, diesel, oil, and propane. Lithium batteries also fall into this category; however, because of their electrical component, they can also be considered Class “C.”
- Class C: Electrical equipment.
- Class D: Combustible metals like sodium and magnesium.
- Class K: Kitchen fires from grease, oils, and fats.
Types of Fire Extinguishers and Their Uses
1. Water Extinguishers (Class A)
Water extinguishers are suitable for fires involving ordinary combustibles like wood, paper, and textiles. These are perhaps the most straightforward type of fire extinguisher.
- Pros: Simple to use, effective on common combustible materials, inexpensive.
- Cons: Inappropriate for flammable liquid or electrical fires; using water on these can be dangerous.
2. Foam Extinguishers (Class A and B)
Foam extinguishers are effective for both Class A fires and flammable liquid fires (Class B), such as gasoline or oil.
- Pros: Versatile for different types of fire risks, helps prevent re-ignition.
- Cons: Not suitable for electrical fires.
3. Dry Powder Extinguishers (Class A, B, C)
Also known as ABC extinguishers, dry chemical powder extinguishers are versatile and effective on ordinary combustibles, flammable liquids, and electrical fires.
- Pros: Versatile, effective on a broad range of fire types.
- Cons: They can be messy and potentially damaging to electronic equipment. The powder can be sucked into engines damaging them and is corrosive if left on metal parts.
4. Carbon Dioxide Extinguishers (Class B and C)
CO2 extinguishers are primarily used for electrical fires and flammable liquids.
- Pros: Leaves no residue, minimizing damage to electrical equipment.
- Cons: Short range, can be ineffective in windy conditions. Is extremely cold and can cause thermal cracking damage to hot engine components.
5. Wet Chemical Extinguishers (Class K)
Specially designed for kitchen fires involving oils and fats, these are vital for commercial kitchens but less common in homes.
- Pros: Effective in extinguishing and cooling cooking oil-related fires.
- Cons: Intended for a very specific type of fire, less useful otherwise.
6. Halotron Extinguishers – Clean Agent (Class A, B, C)
Halotron extinguishers are clean agent extinguishers that are particularly useful in areas with sensitive equipment.
- Pros: Leaves no residue, making them ideal for use in environments with valuable electronics like server rooms and aircraft.
- Cons: More expensive than other types, and the gas needs to be completely contained to be fully effective.
Fire Extinguishers in the Marine Environment
When it comes to pleasure boats, fire safety takes on unique challenges. The confined space, presence of flammable liquids, and often limited escape routes make it essential to equip these vessels with appropriate fire safety measures.
The US Coast Guard sets requirements for fire extinguishers on recreational boats based on the vessel’s length and if there are enclosed spaces such as permanently installed fuel tanks, double bottoms, enclosed living spaces, and stowage compartments. Basically, any cruising boat must have fire extinguishers.
This chart shows the number of extinguishers required based on length.
These are the minimum requirements. We strongly urge you to have extra fire extinguishers on board. A fire on board can quickly get out of control, and when you are out on the open water, assistance can be hours away. Even in a marina, your boat can burn to the waterline and take your neighbors with it before fire crews arrive.
General Usage on Boats
A combination of different fire extinguishers is recommended on a boat to manage various types of fire threats.
- ABC dry powder extinguishers are frequently used due to their versatility in handling different fire types that can occur.
- Halotron extinguishers are ideal for protecting onboard electronic systems without causing damage and are often installed as automated fire impression systems in engine compartments.
Regular checks and maintenance of extinguishers ensure they’re ready for use. Remember, organization matters; placement should be strategic for quick accessibility.
Inspection
The US Coast Guard sets out specific requirements for inspection.
Fire extinguishers must:
- Be on board and readily accessible.
- Be of an approved type.
- Not be expired or appear to have been previously used.
- Be maintained in good and serviceable working condition, meaning:
- If the extinguisher has a pressure gauge reading or indicator, it must be in the operable range or position
- The lock pin is firmly in place.
- The discharge nozzle is clean and free of obstruction.
- The extinguisher does not show visible signs of significant corrosion or damage.
On commercial vessels, the extinguishers and any automated shutdown system must be inspected annually by a certified maintenance provider. This is not a requirement for pleasure vessels; however, it is highly recommended that you have your fire and safety systems professionally inspected every few years.
If you have an insurance or boat purchase survey, the Surveyor will perform this task. Otherwise, check with any Fire Systems company near marinas, and they can arrange for an onboard inspection. You can also bring your portable extinguishers to a Fire Systems company, and they will inspect and label them.
The USCG stopped and inspected us a few years ago. As part of the inspection, they checked every fire extinguisher on board. They even sent someone down into the engine room (with the engines running) to inspect our automatic suppression system! (and to make sure our bilge was clean)
Galley-Specific Fire Safety
The galley, or the kitchen area on a boat, is particularly susceptible to fires due to open flames and the presence of oils. A wet chemical extinguisher (Type K) is ideal for handling such fires.
Given the high risk, installing fire blankets alongside extinguishers can add an extra layer of safety. Fire blankets are inexpensive and easy to use. They can quickly snuff out a fire and keep it from spreading.
Engine Room Fire Suppression Systems
Managing fires in an engine room on a pleasure boat is critical. This is where automatic fire suppression systems come into play, often in the form of clean agent systems like FM-200 or Halotron.
Clean Agent Systems are effective and avoid damaging sensitive engine components. Such systems activate automatically to suppress fires without the need for human intervention, providing peace of mind. These systems remove oxygen from the engine room environment by flooding it with an inert gas. These must be integrated with an engine and blower shutdown system so that the gas is not sucked out through the engine room venting system giving it time to work and avoiding introducing new oxygen into the engine room.
If your automatic (or manual) engine room suppression system is activated, you mustn’t open your engine compartment or restart your engines until you are sure that the fire is completely out and that the potential source of the fire is addressed, such as turning off fuel valves and shutting off the power. Opening the engine compartment or starting blowers or engines will introduce oxygen back into the environment. If there is still a fuel and ignition source, it can cause the fire to restart and, in some cases, result in an explosive flashback.
Our Fire Suppression Configuration
First, let me say that I take fire safety very seriously. I’ve seen what a fire on a boat can do and how quickly it can spread on board and to other boats in a marina environment. On our last Loop trip, a boat caught fire at the dock just after we left the marina. The boat was destroyed, and it burned the dock and heavily damaged two other boats before it could be gotten under control.
This is the fire extinguisher configuration we have on our 42-foot Trawler.
- 1 – 4lb ABC Extinguisher in each sleeping berth. (total 2)
- 1 – 4lb ABC Extinguisher on the Flybridge.
- 1- 4lb ABC Extinguisher mounted near the generator.
- 1 – 5lb Halotron Extinguisher mounted near the helm electronics panel.
- 1 – 5lb Halotron Extinguisher mounted near the electrical panel (which is also accessible from the engine room hatch)
- 2 – 2lb Class ABC-K (Kitchen) Extinguisher: one mounted in the salon near the galley, the other on the cockpit near the gas grill.
- 2 – 40″x40″ Fire Blankets: one mounted near the salon, the other in our front berth. (They can also be used to shield yourself from fire to escape)
- 2 – Fireboy 400 Cu.Ft. HFC-227 (Clean Agent) Automatic Fire extinguishers, one mounted outside each engine, and have backup manual triggers near the helm. Note: My engine room is approximately 300 Cu.Ft. I have double the required capacity. The extinguishers are connected to a FireBoy automatic shutdown system.
- 1 – 2lb ABC Fire Extinguisher mounted in the dinghy.
We have hard-wired Marine-Grade Carbon Monoxide detectors in each sleeping berth and in the salon. Don’t rely on home-type CO detectors; they don’t work correctly on boats. Get a hard-wired, 12-volt detector. When we bought our boat, we hired a training captain. One of his absolute requirements was hard-wired 12-volt marine-grade CO detectors in each berth. (That and a good supply of organic eggs and spinach for breakfast omelets! Hi Geoff!)
I have also installed wirelessly linked smoke/fire detectors in each sleeping berth, the engine room, the cockpit near the generator, and the electronics bay. These are residential units. If one goes off, they all go off.
Engine room automatic fire impression systems should be sized and installed by a professional installer. You can find out more information at: Fireboy.com
Is this excessive? Probably. Have I ever used any of them aboard? Almost. Is it good insurance? You bet!
Fire Strategy
Fire safety equipment onboard a boat is designed to help you perform three key goals:
- Stop a small fire from becoming a big fire.
- Get everyone safely off the boat in the event of a big fire.
- Make the Coast Guard happy if
If your boat has a major fire, the likelihood of saving it is slim to none. Get everyone safely off the boat and away from the fire. Once fiberglass catches fire, it will move fast, and the toxic fumes will overcome you quickly. Live to tell the story and collect on your insurance.
I have had suggestions and seen some boaters carry a “Smoke Hood.” My theory is that if you have time to put on a smoke hood, you have time to get off the boat. GET OFF THE DAMN BOAT!
Fire extinguishers are essential for ensuring safety on land or at sea. Understanding different systems’ specific needs and benefits can help make informed decisions about which types of extinguishers and suppression systems to use, particularly on pleasure boats. Regular maintenance and strategic placement are key elements in effective fire safety planning. Whether in your home, workplace or on the water, being prepared and knowledgeable can make all the difference in the event of a fire.
Are you prepared for a fire onboard? When was the last time you inspected your systems?
Let us know in the comments below! 
Here Are Links To The Products We Use
These are affiliate links. If you make a purchase, we may earn a commission.
Automatic Generator Cabinet Extinguisher
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