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Fire
Extinguisher Safety
Poison Control
The Bottom Line
Proper use of fire
extinguishers is generally safe; however, there is some risk for mild
respiratory, skin, or eye irritation.
Use in areas with
poor air flow, use with intent to harm someone, or intentional inhalation of
fire extinguishers can produce serious toxicity and would require medical
evaluation.
The Full Story
Debate continues
about when humans first started using fire, but controlling and extinguishing
fires were natural developments shortly afterward.
Fire extinguishing
methods in ancient Egypt and Rome included use of hand water pumps and bucket
brigades.
Technology has
advanced considerably to include other fire suppression techniques but still
centers around removal of heat and/or oxygen from a fire and by interrupting
the chemical reaction responsible for the fire.
Today's portable
fire extinguishers are pressurized canisters that release a variety of fire
suppressants including powders, gases, and water.
Most fire
extinguishers should be operated using the PASS technique: Pull out
the safety pin, Aim the extinguisher at the base of the fire, Squeeze
the handle, and Sweep the spray from side to side.
In the US, fires
have five main classifications, and fire extinguisher ratings are based on the
kind of fire they are intended to put out.
Class A fires
involve ordinary materials that easily burn, such as paper, cloth, and some
plastics.
Class B fires are
from flammable liquids such as gasoline, non-cooking oils, solvents, and
alcohols.
Class C fires
involve electrical equipment such as appliances, computers, and power tools
that are plugged into a live/hot electrical outlet.
Typical household
fires are usually class A, B, or C.
Class D fires
involve combustible metals such as lithium, titanium, and zirconium and are
associated with manufacturing facilities.
Class K fires are
due to cooking oils and grease used in deep fat fryers in commercial kitchens.
This article will
focus on portable fire extinguishers typically found in homes and offices.
Many fire
extinguishers release a fine powder. The most common is the multipurpose dry
chemical type, which is used for Class A, B, and C fires.
These contain
monoammonium phosphate, which comes out as a yellow powder. The yellow color
helps to distinguish it from other non-multipurpose extinguishers.
Ordinary dry
chemical extinguishers are used for Class B and C fires only. They often
contain sodium bicarbonate (baking soda), which comes out as a white powder.
Inhalation of
monoammonium phosphate and sodium bicarbonate can cause mild irritation to the
nose, throat, and lungs and results in symptoms like shortness of breath and
coughing.
Dizziness and
headache are also possible. These symptoms usually resolve quickly with fresh
air.
Ongoing minor
irritation often improves after a steam treatment, such as a steamy shower.
People with lung
conditions like asthma or someone deliberately sprayed at close range can have
more serious respiratory effects and might need medical attention.
Contact of these
powders with the eyes, nose, throat, and skin can cause irritation, which
should improve after rinsing the exposed area.
Deliberate
inhalation or ingestion can cause serious symptoms such as pneumonia, seizures,
irregular heartbeat, and kidney failure.
People with more
than mild symptoms or anyone with a deliberate exposure should be managed in a
healthcare facility.
Carbon dioxide (CO2)
fire extinguishers are used for Class B and C fires.
They emit
pressurized CO2 gas, which smothers the fire by blocking the
oxygen that the fire needs.
Unlike the dry
chemical types, this nonflammable gas quickly evaporates leaving nothing
behind. Because the gas is under pressure, pieces of dry ice (solid CO2)
might be emitted.
CO2 is
not to be confused with carbon monoxide.
Carbon monoxide is
a very toxic gas that is generated by burning fuels and can be produced by
faulty gas appliances, car exhaust, and fires.
CO2 is
a naturally occurring gas and is part of the air we breathe. CO2 is
also found in carbonated beverages.
Toxicity from
inhaled CO2 only occurs with very high concentrations.
In most situations,
there is enough oxygen in the area to prevent toxicity. However, toxicity can
occur if a CO2 extinguisher is used in a small, poorly
ventilated area.
Inhalation of
concentrated CO2 causes the same symptoms as not having enough
oxygen, including difficulty breathing, dizziness, and loss of consciousness.
Anyone exposed to
concentrated CO2 should seek fresh air immediately. Medical
attention would be needed for effects that do not resolve quickly or for anyone
who loses consciousness.
Direct contact of
the skin with the pressurized CO2 can cause frostbite.
The damage to the
skin can be limited to mild redness, but blisters are also possible. Damage to
the eyes can also occur with direct exposure.
· Know
how to properly use a fire extinguisher including the "PASS"
technique (pull, aim, squeeze, and sweep).
· Air
out any area where a fire extinguisher has been discharged before reentering
it.
· Never
use a carbon dioxide extinguisher in a confined space with people present
without proper respiratory protection.
· Do
not let children play with fire extinguishers.
· Keep
one or more fire extinguishers in your home. Read the instructions and
understand how to use them before a fire occurs.
This Really
Happened
Case 1. A school nurse
called Poison Control because a child sprayed an ABC-rated fire extinguisher
toward several students and teachers. Some of them had shortness of breath and
coughing while others had nausea, headaches, or irritated eyes. Poison Control
instructed the nurse to have everyone get fresh air and to rinse the eyes of
anyone with redness or irritation. Poison Control determined that the
extinguisher contained monoammonium phosphate and only mild, brief effects were
anticipated. A follow-up call to the nurse was made later in the day, and the
teachers and students were all OK.
Case 2. A 20-year-old
man developed first- and second-degree frostbite injury to his right hand after
using a CO2-containing fire extinguisher. His hand was in prolonged
contact with the CO2 due to a leaky gas valve. The man needed
treatment by a burn specialist.
Case 3. The following
product review was noted on an online retailer website for an ABC-rated fire
extinguisher. "I opened the package and was hit in the face with a
cloud of yellow powder. This was my first fire Extinguisher purchase and I had
no idea what the powder was so I called poison control and learned the thing
had completely discharged in the package. I wish I had read the other reviews
more carefully because it looks like this is not an uncommon occurrence with this…" Needless
to say, the product only received a 1-star rating!
If you suspect
someone has inhaled spray from a fire extinguisher, get them to fresh air
immediately. Exposure of the eyes or skin to any of the dry chemical fire
extinguishers should be treated by immediate rinsing of the affected areas.
After this initial treatment has been performed, check the webPOISONCONTROL® online
tool for guidance or call Poison Control at 1-800-222-1222.
Karen D. Dominguez, PharmD
Certified Specialist in Poison Information
Certified Specialist in Poison Information
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