Selecting Fire Extinguishers


Onboard fires are one of the two most common reasons boaters are forced to abandon ship (other than the obvious one of having your boat sink). Fire extinguishers protect you, but most boaters tend to ignore them. Here’s an opportunity for a quick refresher on this crucial safety gear.

What is the length of your boat?

The Coast Guard requires from one to three extinguishers on pleasure boats, depending on whether they have enclosed engine compartments and if there is a permanently-mounted fixed extinguisher system in the engine room. Like other Federal requirements, these are really minimal. Buy enough to satisfy the requirements and then address the needs of your particular boat.

  • Up to 26': One B-I size extinguisher. Fire extinguishers are not required on outboard-powered pleasure boats less than 26' in length, not carrying passengers for hire, without permanently-installed fuel tanks, that do not have spaces where explosive or flammable gasses or vapors can collect.
  • From 26' to 40': Two B-I extinguishers (or one B-II extinguisher)
  • From 40' to 65': three B-I extinguishers (or one B-I and one B-II)

These are the minimums to pass the Coast Guard inspection if you get boarded, but extinguishers are only effective if you can get to them. We recommend at least one in the cockpit, one in each stateroom and one in the galley area, reachable even if the stove is on fire. Statistically speaking, an onboard fire doubles in size every seven seconds, so having a fire extinguisher readily available may make the difference between inconvenience and catastrophe.

What materials will they extinguish?

The ABCs of fire classification

  • Class A fires leave an ash—all combustible solid materials, such as paper, wood, cloth, rubber, and many plastics including the fiberglass reinforced plastic used for decks and hulls.
  • Class B fires boil—all flammable liquids, including stove alcohol, grease, gasoline, diesel, kerosene, oil, oil based paint, teak oil, paint thinners, acetone, varnishes, and flammable gases or fumes.
  • Class C fires involve a charge—all energized electrical equipment. Class C fires are identified for their potential to electrocute or shock a person if you apply electrically conducting water-based extinguishing agents. Turning off the electricity is the top priority when fighting a Class C fire. Usually you can turn off the main battery switch. Safe and effective circuit protection is likewise crucial for preventing Class C fires. Cutting the power will change the status of a Class C fire to a Class A and/or B fire.

 

Ratings on a fire extinguisher reflect an extinguisher’s ability to combat particular classes of fires. Underwriters Laboratories (UL) uses letters to denote the type of fires the extinguisher is capable of fighting, and numbers to refer to the fire fighting “capacity” relative to other extinguishers. For example, a 1-A;10-B:C extinguisher is effective on Class A, B, and C fires, and a 40-B:C extinguisher isn’t rated for Class A fires, but has four times the extinguishing capacity of a 10-B:C extinguisher.

The Coast Guard quantifies extinguisher abilities differently from UL, and they use the terms B-I and B-II. The difference is that the Coast Guard looks only at the weight of the extinguishing agent, while UL looks at the fire fighting ability.

This table shows how the Coast Guard and UL classifications align, and how much active ingredient is stored in each class.

USCG Class

UL-Listed Equivalent

Foam (gal.)

CO2 (lb.)

Dry Chemical (lb.)

B-I

5-B:C

1.25

4

2

B-II

10-B:C

2.5

15

10

 

What type of extinguishing agent?

Water – Good for Class A fires. Extinguishers are heavy, difficult to store, and are NOT for use on flammable liquid or electrical fires.

Carbon Dioxide (CO2) – Good for Class B and Class C fires. No residue. Easy to use. Useful only in confined interior spaces. Does not cool fire.

HFC-227ea – Relatively non-toxic Halon replacements are effective on all fire classes. Expensive.

Novec™ 1230 – New 3M agent is an environmentally-sustainable replacement for HFC-227 or FM200. No potential damage to the ozone layer or global warming potential. Effective on all fire classes and leaves no residue after use.

Halotron 1 – EPA-approved. Safe for computers, electronics, even clean rooms, and leaves no residue after use.

Dry Chemical – Low toxicity. Inexpensive. Effective on Class B and Class C fires. Not effective on Class A fires. Difficult to clean up.

Tri-Class Dry Chemical – Low toxicity. Inexpensive. Effective on Class B and Class C fires. Moderately effective on Class A fires. Difficult to clean up. Corrosive. Not a good choice for helm or nav station.

Aqueous Foam – This relatively new technology is extremely easy to use effectively on Class A, B, and C fires. Avoid excessive skin or eye contact.

BoatU.S. tested fire extinguishers in 2009. View their highly informative series of seven short videos.

PASS: Fighting a fire with a portable extinguisher

Typical fire extinguishers have a discharge time of only about 10 to 12 seconds, so you have to use them before the fire gets too large. Deep-seated fires that seem to be out may flare up again, and this short discharge time, combined with the possibility of reflash, are important reasons to carry extra extinguishers onboard.

To quickly remember how to fight a fire with a handheld fire extinguisher, use this easy-to-remember acronym called PASS:

  • Pull the pin
  • Aim the fire extinguisher
  • Squeeze the two handles together
  • Sweep across the base of the flames

Where should the extinguishers be located?

Extinguishers are only effective if you can get to them. We recommend at least one in the cockpit, one in each stateroom and one in the galley area, reachable even if the stove is on fire. Statistically speaking, an onboard fire doubles in size every seven seconds, so having a fire extinguisher readily available may make the difference between inconvenience and catastrophe.

 

The information provided here has been reproduced courtesy of US Boats OC Boat Supplies reproduced this information  01/05/2014.