CARBON DIOXIDE AS AN EXTINGUISHING AGENT
The "Kidde" Fire Extinguishing System uses carbon dioxide gas as the extinguishing agent. Carbon dioxide is a
standard commercial product, being most commonly used for carbonating beverages, and is available in most of the large
cities and seaports throughout the world.
Carbon dioxide is normally colorless except that, when discharging, it resembles a cloud of steam. When inhaled
in small amounts, it produces a tingle in the nostrils the same as experienced when drinking soda water. It is a non-
conductor of electricity, is non-corrosive, and non-injurious to all substances, and although heavier than air, it does not
contain oxygen in any form available for supporting combustion or for sustaining human life in breathing.
"Fast" fires such as engine room, oil, or paint fires, are quickly extinguished by flooding the area with carbon
dioxide gas. This reduces the oxygen content and creates an inert atmosphere which smothers the fire. "Slow" or "Deep-
seared" fires, such as fires in paper-clothing or similar substances, are extinguished by prolonged action of a high
concentration of carbon dioxide. In addition to its smothering action, carbon dioxide is aided in extinguishing fire by its
cooling effect.
Since a person will have difficulty in breathing and may suffocate in an atmosphere of carbon dioxide, caution
must be taken before entering any space filled with this odorless gas. Thoroughly ventilate the space into which the gas
has been discharged to make certain that all portions contain only fresh air.
If it be necessary for a person to enter a space before it is thoroughly ventilated, he may do so by using a fresh air
mask or other type of self-contained breathing apparatus. DO NOT USE a filter type of mask or a canister gas mask. No
one should enter such & space without another person as observer and standby outside the space.
Should a person be overcome by carbon dioxide, it is essential that he be immediately rescued from the space
containing the gas. Call a physician. To revive a person so overcome, give him plenty of fresh air and apply artificial
respiration (as in the case of drowning) using oxygen, but do not use carbon dioxide as a stimulant.
An ammonia inhalant may be used and the person should be kept warm (by the application of friction and heat to
the extremities).
The carbon dioxide is stored in liquid form in steel cylinders carefully tested for strength under governmental
supervision. The pressure within the cylinder depends on the temperature, being 504 pounds per square inch at 32
degrees F. and 850 pounds per square inch at 70 degrees F., although the carbon dioxide content is never determined by
using a pressure gauge. The gas content may be determined only by the weighing of the cylinder.
Each cylinder is provided with a safety relief disc which will release the gas before the pressure exceeds the
cylinder test pressure. Cylinders should be stored in a cool place whenever possible. The maximum safe storage
temperature for all cylinders is 130 degrees F. Specially charged cylinders can be supplied for higher storage
temperature.
