Picking the right fire extinguisher

When supplying a building with fire extinguishers and suppressants, ensuring the security of the entire structure is extremely important. As mentioned in NFPA 10 Chapter 1, portable fire extinguishers are intended to be the first line of defense for fires of a limited size and can be used in several areas including vehicle repair, aircraft and marine servicing, cooking areas, and storage and m...

11/01/2008


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When supplying a building with fire extinguishers and suppressants, ensuring the security of the entire structure is extremely important.

As mentioned in NFPA 10 Chapter 1, portable fire extinguishers are intended to be the first line of defense for fires of a limited size and can be used in several areas including vehicle repair, aircraft and marine servicing, cooking areas, and storage and manufacturing processes (painting, dipping, coating, and the handling of flammable liquids). The following steps will help you determine the right fire extinguishers and agents for your own building.

1. Perform a site survey

In order to properly classify the right extinguisher necessary and where it should be located in a room, a thorough site survey must be completed. This should be conducted with a facility representative that is well-versed in the layout, O&M, and processes of the building.

In addition, it is helpful to have detailed sketches of the building layout including specifications on doorways, aisles, stairways, interior structures, machinery, and equipment locations—all places that may not be initially considered. Having floor plans handy also is helpful and recommended because it helps visualize the entire floor layout, and can be helpful later on when determining the distribution of fire extinguishers.

When analyzing, identify potentially hazardous conditions such as liquids, chemicals, and atmospheric gases. Evaluate the potential severity of a resulting fire and make sure that you have both the personnel and equipment to handle it. Keep staff members trained on how to handle equipment as well as potential operational hazards.

2. Selecting the proper type of extinguisher

When selecting a fire extinguisher, special thought should be given to the potential occupancy hazards within the facility that might require additional protection. Keep in mind the manufacturing processes that are taking place in the building, as well as flammable liquid handling and storage areas. This can help determine the potential severity of a fire, which is key when deciding the type of extinguisher required. Mixing volatile chemicals in an area can either start or add to the intensity of a fire. Other potential hazards in the building that would require special attention are equipment repair areas, which are potential areas for 3-D class B fires; gases in the atmosphere; and areas that have pressurized flammable liquids and gases.

There are five classifications of extinguishers (see Table 1) that are used to put out different types of fires. When considering the best fit for your building, determine which class of fire extinguisher and type of discharge works best.

3. Distributing and placing fire extinguishers

When taking into account the number of extinguishers to use and where to place them, the most important factors to consider are location, even distribution, accessibility, placement, visibility, and hazardous conditions.

First, fire extinguishers should be evenly distributed throughout the facility, with at least one per floor. Fires can break out at any part of a building, making it necessary to have proper extinguishers easily accessible from anywhere on the floor.

Moreover, accessibility is just as important as placement, meaning extinguishers need to be within reach without obstacles that make them difficult to grab in a hurry. Additionally, placing extinguishers near normal paths of travel add to the tool's visibility and will also likely make response times to fires quicker. Lastly, positioning extinguishers near entrances and exits can enable people to escape if necessary should a fire block a door or stairway.

Protecting extinguishers is another key to fire safety. When identifying potential locations, ensure that extinguishers are clear of any hazards such as mobile equipment that may damage or block the extinguisher during an emergency. Ordinarily, fire extinguishers can be placed on a standard hanger hook. However, if an extinguisher is to be placed in an area where it could be dislodged, it should be protected by securing it in a strap bracket or placing it in a cabinet.

4. Maintenance of extinguishers

After you have selected and installed the extinguishers for your building, proper maintenance will ensure their effectiveness. According to NFPA's manual, “extinguishers are to be maintained regularly, not more than one year apart, unless otherwise specified in the manual.” It is recommended that in addition to yearly checks, there should be monthly checks (see Figure 2), which can be conducted by a trainer. The purpose here is to reassess the effectiveness of the placement of the extinguisher, its visibility, accessibility, and the level on the pressure gauge.

A yearly examination consisting of a complete check the externals of the unit should be conducted by someone who is fully trained, and in some jurisdictions, a certified extinguisher distributor. The goal is to determine if there are any repairs, recharging, or replacement of equipment necessary. If so, old extinguishers that no longer function must be replaced by a spare of the same type with at least equal ratings.

5. Disposal

Once it's been determined that an extinguisher needs to be disposed, follow the protocol below to avoid pollution and further accidents. It is recommended that you contact your local authorized distributor to see if they handle the disposal of extinguishers. Usually they are trained to handle this and it is also usually covered in their service.

If disposing dry chemical, you need to obtain the material safety data sheets so that you can find out which chemicals are in the agent and their potential toxicity—information that could be required by a waste disposal company. Lastly, if you choose to dispose the extinguishers on your own, which is not recommended, destroy the shell by drilling holes of at least 9/16 inch so that it cannot be reused. This is mandatory because unused or empty shells gather rust and corrosion over time which makes them unsafe for use.

Class

Use

Agent types

Typical applications

Source: Tyco Fire Suppression & Building Products

A

Common combustibles

%%POINT%% Water (typically used for wood, paper, or grass) %%POINT%% Multipurpose dry chemical (typically used for paper, wood, and tires; in garages, schools, and hospitals)

Paper, cloth, wood, tires, rubber, plastics, garbage, and grass

B

Flammable liquids and gases

%%POINT%% Dry chemical (garages, service shops, factories, delivery vehicles, cars)

Gasoline, diesel, hydraulic oil, paint thinner, flammable gas, and grease

C

Energized electrical equipment

%%POINT%% Dry chemical (offices, warehouses, factories) %%POINT%% Carbon dioxide (electrical cabinets, electrical generators, clean rooms) %%POINT%% Clean agent (computer rooms, electrical cabinets, hospitals, telecommunication equipment, laboratories)

Computers, power cords, telecommunication equipment, and lights

D

Burning metals

%%POINT%% Class D dry powder (machine shops, factories working with turning/cutting metals, municipal fire trucks, auto body shops)

Potassium, magnesium, sodium, lithium, and titanium

F

Combustible cooking oils

%%POINT%% Wet chemicals (commercial kitchens)

Oils and fats used in cooking


Author Information

Beranek is the standard products marketing manager for Tyco Fire Suppression & Building Products. He has been involved in portable extinguisher marketing for the past 10 years. He is an active member and current president of the Fire Equipment Manufacturers Assn. and serves as vice-chair for the group's Government Relations Group.




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