Flammable and combustible products are used for a wide variety
of purposes and are commonly found in the home. Gasoline is the most common,
but there are other flammable and combustible liquids and gases used in the
home including:
- paint solvents
- lighter fluid
- dry cleaning agents
- butane
- pesticides
- oil
- spray paint
- kerosene
- propane
- diesel fuel
- turpentine
- nail polish
Many households use natural gas, propane or fuel oil heating.
Each product poses a serious health or fire danger if not used and stored
properly.
Background Information
A flammable liquid in its liquid state will not burn. It only
will ignite when it vaporizes into a gaseous state. All flammable liquids
give off vapors that can ignite and burn when an ignition source such as a
lighted cigarette or spark is present.
To understand the dangers associated with flammable liquids,
it is useful to be familiar with the terms used to describe their chemical
properties. They are:
Flash point - The temperature at which a particular flammable liquid gives off vapors
(vaporizes) and therefore can ignite. The flash point differs for each type
of flammable liquid. Kerosene has a flash point of 110 degrees Fahrenheit.
Gasoline has a flash point of -40 degrees. This means that at 110 degrees
or higher kerosene gives off flammable vapors and can ignite. However, gasoline
requires a temperature of only 40 degrees to vaporize to cause an explosion
or fire. This means that when the temperature is freezing, gasoline still
vaporizes and can cause an explosion and/or fire. At the same temperature,
kerosene cannot ignite. Liquids such as gasoline with a flashpoint below 100
degrees are called flammable liquids. Kerosene and other liquids with
a flash point above 100 degrees are referred to as combustible liquids.
Flammable range refers to the percentage of a flammable liquid, in its gaseous state,
to air to create an explosive mixture. This varies with different flammable
liquids. Gasoline has a flammability range of 1.4 to 7.6 percent. This means
it will ignite when there is 1.4 parts of gasoline mixed with 100 parts air.
With this in mind, 1.4 percent is known as the lower flammable limit and 7.6
percent is the upper flammable limit of the flammable range. A product mixed
with air below the low end of its flammable range is too lean to burn. A flammable
liquid which exceeds its upper flammable limit is too rich to ignite. Ethylene
oxide is extremely flammable. It has a flammable range of 3.6 to 100 percent.
This means it can burn even if there is no air.
Gasoline has a narrow flammable range and is metered precisely
in a vehicle's carburetor to obtain the desired flammable range. A vehicle
will have trouble operating if the carburetor meters too much gasoline. This
is referred to as a rich mixture, which is too concentrated for ignition by
the spark plugs. Too little gasoline in a vehicle's carburetor is called a
lean mixture, which is too diluted for ignition.
The ignition temperature is the temperature required
for a liquid to continue to emmit vapors which can and sustain combustion.
Gasoline will ignite when a heat source or electrical spark of at least 853
degrees comes in contact with it. Natural gas (methane) needs an ignition
temperature of around 1000 degrees and paint thinner 453 degrees.
Vapor density is the weight of a vapor relative to the weight of air. The vapor density
of natural gas causes it to be lighter than air and will rise when exposed
in the open. The vapor density of gasoline is heavier than air and will seek
low points when it is exposed to the air. Products with a high vapor density
(heavier than air) behave much like carbon dioxide gas escaping from a block
of dry ice. (Dry ice is frozen carbon dioxide gas.) A term used in the fire
service is BLEVE. It is an acronym for "Boiling Liquid Expanding Vapor
Explosion." A BLEVE occurs when a confined liquid is heated above its
atmospheric boiling point. The vapors expand and suddenly the container will
explode.
Gasoline and Other Flammable Liquids and Gases
Gasoline
Gasoline is the most common flammable liquid found in the home. Used carelessly
or improperly, it is the main cause of burn injuries among teenage boys. Gasoline
is highly volatile due to its low flash point and easily vaporizes when exposed
to air. Because it is heavier than air, it can seek out ignition sources such
as a pilot light from a water heater, an electical spark from a hand tool,
or a lit cigarette dropped on the ground. Use care when filling lawn mowers,
chain saws and other power tools with gasoline. Don't refill a power tool
with the engine running or while the manifold is hot. Use a funnel to pour
the gas to avoid overfilling and spilling. If gasoline is spilled, allow it
to vaporize completely. This will maintain a dry surface and reduce the chance
of ignition. Never fill gasoline in a confined space, indoors or in a closed
garage.
Never smoke around gasoline or other flammable liquids. Do
not use it as a cleaning solvent or to remove grease and oil from automotive
parts, your hands or clothing. Many people are seriously burned each year
from these mistakes. Do not pour gasoline or other flammable liquids down
the sink or into a storm drain. This creates an explosion potential.
Do not store gasoline in the house. It should be kept in a
detached garage or in an outside storage area. Be absolutely sure it is clear
from any ignition source such as a water heater, washer or dryer. Do not put
gasoline in a cup, glass jug or old bleach bottle. It should be stored in
an approved container, which is of heavy duty construction, has a spring-loaded,
self-closing handle and is equipped with a safety-relief plug.
Don't store gasoline in the trunk or back of the car. If you
need to carry fuel, make sure the cap is tightly closed, and fill the can
only three-fourths full, leaving an air space for vapor expansion.
Kerosene
Kerosene heaters are commonly used in many homes and businesses during colder
months of the year to provide warmth. Kerosene is not as flammable as gasoline
but just as dangerous. Fill a kerosene heater outdoors using a fill spout.
Never fill a heating unit while hot and be sure the area is ventilated. Kerosene
should be stored away from the home and any heat or ignition sources. It should
be stored in an approved container like gasoline.
Other flammable liquids and gases
For health and safety reasons, paint should be used in a ventilated area.
It should be stored in a secured can when not being used. Spray paint and
paint solvents such as lacquer thinner, and paint brush cleaner are highly
flammable and should be stored away from heat or ignition sources. Other cleaners
such as naptha and toluene can be ignited by static electricity from one's
clothing. These products should be stored in secured containers away from
the home in a detached storage area.
You may have a good reason to have benzine in the house - as
a dry cleaning fluid or as a fluid for your cigarette lighter. Even then,
you should keep the smallest quantity possible on hand...in a tightly stoppered
container...stored securely away in a cool place. Benzene (with an "e"),
otherwise known as benzol, is a very serious fire and health hazard (a known
carcinogen). Do not use or store it under any circumstances.
Denatured alcohol may be required for some uses in the home,
perhaps as a rubbing solution. While it is not quite as dangerous as some
of the others, it is nonetheless highly flammable and should be used and stored
with as much caution as any other flammable liquid.
Many pesticides are not only poisonous, but are highly flammable.
When using pesticides, be sure you are away from any heat or ignition source.
Always keep pesticides in their original containers.
Rags which have been used to wipe or clean petroleum products
may spontaneously ignite. Cleaning rags soaked in oil, furniture polish, turpentine,
or paint should be kept in a tightly-sealed metal container or thrown away
immediately after use.
Survival Actions Regarding Flammable Liquids
Even if you have a small spill involving a flammable liquid,
immediately open your windows to ventilate the area. Do not use fans
or other electrical devices, which might provide an ignition source and cause
an explosion. If you get some of the liquid on your skin, remove the affected
clothing and wash your skin with soap and water. Soak your clothes in water
before washing them. If a large spill occurs, evacuate the area immediately
and call 9-1-1.
A small fire involving a flammable liquid can be controlled
with a class B fire extinguisher. Never try to extinguish a flammable
liquid fire with water. This could cause the fire to spread. Do not try to
control a fire involving compressed gases such as butane or propane. They
are extremely dangerous. For a large fire involving a flammable liquid, evacuate
the area and call 9-1-1.
