Table 1-2.--Types of Fire Extinguishers

shut off, a potential may remain until an effective

Grasp the horn handle by the insulated

ground is established in some electronic equipment. It

(thermal) grip; the grip is insulated against

is emphasized that the nozzle should not be advanced

possible frostbite of the hand.

any nearer to the power source than 4 feet. Avoid

Squeeze the release lever (or turn the wheel)

prolonged exposure to high concentrations of carbon

to open the valve and release the carbon

dioxide in confined spaces since there is danger of

dioxide; at the same time, direct the discharge

suffocation unless an oxygen breathing apparatus

flow of the carbon dioxide toward the base of

(OBA) is used.

the fire.

ELECTRICAL SHOCK

Aim and move the horn of the extinguisher

slowly from side to side.

As an IC Electrician, you will be working in areas

Do not stop the discharge from the

and on equipment that pose serious shock hazards. If

extinguisher too soon. When the fire has been

you always follow the safety precautions outlined

extinguished, coat the critical surface areas

earlier, you can minimize the risk. However, you

involved with carbon dioxide "snow" to

should remember that the possibility of electrical

smother the fire by displacing oxygen,

shock is always present. If you are at the scene of a

mishap, you will be expected to help the victim as soon

Do not lose positive control of the

bottle.

as possible.

Table 1-2 is a list of the types of fire extinguishers

When 60-Hz ac is passed through a human body

that are normally available for use. Fire extinguishers

and the current is gradually increased from zero, it

of the proper type must be conveniently located near

could cause the following effects:

all equipment that is subject to fire danger, especially

high-voltage equipment. You should be extremely

1 milliampere (0.001 ampere)--shock is

careful when using fire-extinguishing agents around

perceptible.

electrical circuits. A stream of salt water or foam

directed against an energized circuit can conduct

10 milliamperes (0.01 ampere)--shock is of

current. When water is broken into small particles,

sufficient intensity to prevent the voluntary

(nozzle fog patterns), there is little or no danger of it

control of muscles. A person may not be able

carrying electric current under normal conditions of

to release the circuit.

fire fighting if the nozzlers are operated at least 4 feet

100 milliamperes (0.1 ampere)--shock is usu-

from the energized source. Nozzles and Navy

ally fatal if it is sustained for 1 second or more.

all-purpose (NAP) applicators, constitute a shock

hazard to the fire fighter due to accidental shifting to

The danger of shock from 450-volt ac ship's

a solid stream or by touching electrical equipment,

service systems is well recognized by operating

particularly with the applicator. Even after current is

personnel as shown by the relatively few reports of

serious shock received from this voltage. On the other

Table 1-2.--Types of Fire Extinguishers

hand, a number of shipboard fatalities have occured

because of contact with 115-volt circuits. Despite a

widespread but totally unfounded popular belief,

low-voltage (115 volts and below) circuits are very

dangerous and can cause death. Shipboard conditions

contribute to the severity of shock because the body is

likely to be in contact with the ship's metal structure

and the body resistance may be low because of

perspiration or damp clothing.

Keep your clothing, hands, and feet dry if at all

possible. When you must work in a wet or damp

location, use a dry, wooden platform to sit or stand on,

and place a rubber mat or other nonconductive

material between you and the wood surface. When you

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