Marine Fire Extinguishers: Essential Tips and Guidelines
Types of Fire Extinguishers:
Fire Extinguishers are classified by letters and numbers according to the class (type) and the size of fire they can put out. The letter (A, B or C), indicates the class of fire. The number (e.g., 5-B,
20-B, 40-B) refers to the square footage of flammable liquid fire it can extinguish. 5-B is effective on a fire up to 5 square feet in area. A 20-B can handle a fire up to 20 sqft.
Note that Class A uses the equivalent to gallons
of water effectiveness, e.g. 1-A is equivalent to 1.25 gallons of water.
Each class of fire has its own suppression considerations:
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Class A fires involve burning solids such as wood, paper, cloth, rubber and some plastics. These are the only fires which can be extinguished with water. Symbol: Green triangle.
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Class B fires are flammable liquids and gases such as gasoline, diesel, kerosene, alcohol, grease, paints, propane, etc. Symbol: Red square.
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Class C fires involve live electrical circuits and include machinery, appliances, electrical panels, and wiring. Symbol: Blue circle.
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Class D fire extinguishers are designed specifically for fires involving combustible metals, such as magnesium, titanium, sodium, and lithium. Symbol: Yellow five-pointed star
Most marine fire extinguishers are rated B:C (for fighting Class B or C fires), or A:B:C (for fighting all classes of fires). These extinguishers often contain an inert, “dry” chemical extinguishing agent, such as sodium bicarbonate, which physically coats the fuel and prevents it from accessing oxygen, thereby extinguishing the fire.
B:C and A:B:C extinguishers may also contain inert gases, such as CO2, FE-241, FM-200, or Halotron. These work by displacing the oxygen-containing air around the fire, thus smothering it. Unlike dry chemicals, these gases leave no residue and make for an easier cleanup.
Class D extinguishers use dry powder agents that smother the fire by separating the fuel from oxygen and absorbing heat. They are commonly used in industrial settings where metal shavings or reactive alloys are present. Standard extinguishers like Class A, B, or C are ineffective (and can be dangerous) on metal fires.
The following table shows what typically comes inside a class B extinguisher.
| Class | Foam (gals) | Dry Chemical (lbs) | CO₂ (lbs) |
|---|---|---|---|
| 5-B | 2.5 | 2 | 5 |
| 10-B | 5 | 4 | 10 |
| 20-B | 10 | 8 | 15 |
| 40-B | 15 | 16 | 20 |
| 80-B | 30 | 30 | 35 |
The values are approximate and can vary slightly by manufacturer or extinguisher type.
Coast Guard Boat Fire Extinguisher Regulations and Updates:
In recent years, the regulations surrounding boat fire extinguishers have evolved to enhance safety measures and ensure that all vessels are prepared for fire emergencies. The USCG regularly revises its guidelines to adapt to new safety technologies and findings, making it imperative for boaters to stay informed about these changes. For instance, the adoption of new fire extinguisher types, such as those specifically designed for Lithium Iron Phosphate (LiFePO₄) batteries, has become essential due to the unique fire risks these batteries pose. Additionally, boaters are now encouraged to evaluate the adequacy and condition of their onboard extinguishers more frequently, as regular inspections are crucial for maintaining compliance with updated safety standards. Understanding these regulations and updates not only ensures that your vessel is compliant but also maximizes your safety and readiness in the event of a fire. Staying abreast of these changes may involve consulting the Coast Guard's website or local marine safety authorities, ensuring that your fire safety equipment is always up-to-date and effective.
As you can see from their choice of Class B extinguishers, the Coast Guard's primary concern is that you be able to fight fuel-related fires, including electrical fires, which can't be fought with water, highlighting the importance of proper safety equipment.
The table below shows what is required and refers to any boat with an inboard engine, enclosed spaces where vapors could be trapped, or a permanently installed fuel tank. If a U.S. Coast Guard-approved fixed fire system is installed for the protection of the engine compartment, the required number of handheld fire extinguishers may be reduced in accordance with the chart.
Minimum number of hand portable fire extinguishers required:
| Vessel Length | No Fixed System | With Approved Fixed Systems |
|---|---|---|
| Less than 26 ft | One 5-B or 10-B | None required |
| 26 ft to less than 40 ft | Two 5-B or two 10-B or one 20-B |
One 5-B or one 10-B |
| 40 ft to 65 ft | Three 5-B or three 10-B or one 20-B and one 5-B or one 10-B |
Two 5-B or two 10-B or one 20-B |
| Over 65 ft | USCG fire extinguisher requirements are based on gross tonnage | |
Important Notes:
- Model Year 2018 or Newer: If the boat is a 2018 model year or newer, portable extinguishers must be labeled as 5-B, 10-B, or 20-B. Extinguishers labeled with B-I or B-II only are not acceptable.
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Model Year 2017 or Older: If the boat is a 2017 model year or older, either of the following may be carried:
- Unexpired 5-B or 20-B rated fire extinguishers.
- B-I or B-II rated fire extinguishers that are in good and serviceable condition.
- When the B-I or B-II extinguishers are no longer serviceable, they must be replaced with newer class 5-B or greater extinguishers.
- "Good and Serviceable" Condition: Portable fire extinguishers must be in "good and serviceable" condition, regardless of type or model year.
Fixed fire extinguishing systems deploy automatically when a fire is detected and are usually found in engine rooms. They are particularly effective in the enclosed space of an engine room where they quickly fill the entire volume with a “clean” agent, thus removing the fire's access to oxygen. While not specifically required by the Coast Guard, they are one of the most valuable fire fighting tools you can install on your boat.
Bear in mind that the above minimum requirements are just that….the minimum. This is especially true considering that most people are inexperienced in the proper use of an extinguisher, that a 5-B extinguisher only provides about 8 to 12 seconds of fire fighting capability, and that re-ignition is common. Prudent mariners will install additional and/or larger extinguishers for an extra margin of safety. You should also consider spending the few extra dollars for a tri-class (A:B:C) extinguisher instead of settling for the less expensive B:C unit.
Placement and Use:
The location of your portable extinguishers can be critical in the event of a fire on board. At a minimum, you should never have to travel more than half the length of the vessel to get to an extinguisher, especially since most experts state that new fires can double in size in just 30-60 seconds. It's very important to consider how your path to the extinguisher could be blocked in the event of a fire. Spend time analyzing where fires are most likely to occur and place fire extinguishers strategically while thinking about the direction you may be attacking each fire from. If you can't get to an extinguisher when you need one, it's worthless.
For your safety, we urge you to review the basic rules for deciding how and when to fight fires on your own. The rate with which a fire on a boat can spread, particularly in the presence of highly flammable materials, producing volumes of toxic gases which can quickly overwhelm occupants, is particularly sobering. Boat US and the US Coast Guard are two good resources for educating yourself about boat fires.
If you decide to stay and fight the fire, remember the “PASS” Principle:
- Pull the pin at the top of the cylinder
- Aim the nozzle at the base of the fire
- Squeeze or press the handle
- Sweep the contents from side to side at the base of the fire until it goes out
Remember that even when a fire seems to be out, it may still flare up again. The biggest mistake is usually to stop spraying too soon – so make sure you keep sweeping until you are sure the fire is completely out.
Fire extinguishers Inspection
Regular inspection of your portable extinguishers is vital to ensure they remain functional and effective in emergencies. A thorough inspection should be conducted monthly, focusing on several key aspects. Start by checking the pressure gauge reading to confirm that it indicates the extinguisher is fully charged. A gauge in the green zone signifies that the extinguisher is ready for use. Next, examine the seals to ensure they haven't been tampered with. Broken or missing seals can indicate that the extinguisher may have been previously used or altered, which could compromise its effectiveness.
Additionally, inspect the discharge nozzle and hose for any visible signs of damage, such as cracks or corrosion. A compromised hose or nozzle can hinder the extinguisher's ability to function properly during an emergency. For dry chemical extinguishers, it's important to weigh the unit to verify it meets the minimum weight specified on the label, as this can be an indicator of whether the chemical agent inside is still effective.
When inspecting your fire extinguishers, part of your inspection should include inverting and shaking dry chemical extinguishers to break up any compacted chemical at the bottom. If you have any doubts about the functionality of your extinguishers, have them professionally inspected or replace them. This is cheap insurance against a future fire.
Lastly, remember that if a fire extinguisher has been used, even partially, it should be recharged or replaced immediately. Keeping a close eye on the condition of your fire extinguishers, including checking for visible signs of significant corrosion, not only ensures compliance with safety regulations but also prepares you for any unforeseen events on the water.
Servicing:
Fire extinguishers do age and gauges do fail. Every 5 years you should consider having them re-certified by a professional, even if they are still reading “in the green”. The most reliable method is to have them weighed to assure they are fully pressurized and ready to go to work.
Disposal:
Most fire extinguishers will last approximately 10-12 years if properly maintained. Checking the date of manufacture can help determine their lifespan. If it's time to dispose of your old extinguisher, first call your local fire department to see if they will accept old expired units. If they won't, you will need to take your fire extinguisher to your nearest hazardous waste disposal facility. Even more importantly, replace those fire extinguishers immediately!
While we all hope that we will never have to face a fire on board our boat, it's important to be prepared for the worst. Making sure you have the right equipment on your boat, including a fire extinguisher with a clean discharge nozzle, and knowing how to maintain and use it means you will be ready in the case of an emergency.
Fisheries Supply carries a wide variety of fire extinguishers from all the best manufacturers, including Kidde and Fireboy.
Engine Room Fire Suppression
Fire in a boat’s engine room is one of the most dangerous emergencies a recreational boater can face. Engine compartments contain fuel, electrical wiring, and hot surfaces, creating a high risk for rapid fire spread. Effective fire suppression is essential for safety and to protect your investment.
Automatic Fire Suppression Systems
For most recreational boats, the safest and most effective solution is an automatic fire suppression system installed directly in the engine compartment. These systems detect and extinguish fires quickly, often before the crew is even aware of the danger. This rapid response is crucial, since opening the engine hatch to fight a fire manually can feed the flames with oxygen and worsen the situation. Modern fire suppression systems, like the Fireboy-Xintex MA2 Series, use a FK-5-1-12 clean agent.
How Clean Agents Work
Clean agent fire suppressants, such as FK-5-1-12 (also known as Novec 1230), are popular for marine use because they leave no residue, are safe for electronics, and do not harm people at typical concentrations. They suppress fires by absorbing heat and interrupting the combustion process, not by displacing oxygen, so they are safe to use in occupied spaces. Systems using FK-5-1-12 typically extinguish fires in under 10 seconds, minimizing damage and risk.
FAQs
What fire extinguisher to keep on a boat for LiFePO₄ batteries?
For boats equipped with lithium iron phosphate (LiFePO₄) batteries, the recommended fire extinguisher is one specifically designed for lithium battery fires, using Aqueous Vermiculite Dispersion (AVD) technology. Traditional marine fire extinguishers—such as dry chemical (ABC), CO₂, or foam—are generally ineffective against lithium battery fires and may not prevent re-ignition or thermal runaway.
What would you do during a boat fire?
In the unfortunate event of a boat fire, staying calm and taking quick action is crucial. Here are steps you should follow:- Alert Others: Quickly notify everyone on board about the fire to make sure they can evacuate safely.
- Position the boat so the fire is downwind, keeping smoke and flames away from people and critical areas.
- Assess the Situation: Determine where the fire is located and how severe it is. If it's small and manageable, you might attempt to extinguish it.
- Use Fire Extinguishers: If safe to do so, grab a fire extinguisher and aim it at the base of the flames. Remember to pull the pin, aim low, squeeze the handle, and sweep side to side.
- Evacuate if Necessary: If the fire spreads or becomes uncontrollable, immediately evacuate everyone from the boat using life jackets. Deploy the life raft if one is available.
- Call for Help: Use a radio or mobile phone to call for emergency assistance. Provide your location and details about the situation.
- Get to Safety: Move away from the boat to a safe distance in case of explosions or further danger.
- Follow Up: Once safe, make sure everyone accounted for and await help from emergency services.
We hope you've enjoyed this guide, but if you have any additional questions, please don't hesitate to contact our product experts at (800) 426-6930.