1.1 What is gasoline? |
1.2 What happens to gasoline when it enters
the environment? |
1.3 How might I be exposed to gasoline? |
1.4 How can gasoline enter and leave my
body? |
1.5 How can gasoline affect my health? |
1.6 Is there a medical test to determine
whether I have been exposed to gasoline? |
1.7 What recommendations has the federal
government made to protect human health? |
1.8 Where can I get more information? |
References |
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June 1995 |
Public Health Statement |
for |
Automotive Gasoline |
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This Public Health Statement is the
summary chapter from the Toxicological
Profile for automotive gasoline. It is one in a series
of Public Health Statements about hazardous substances and
their health effects. A shorter version, the ToxFAQs™,
is also available. This information is important because this
substance may harm you. The effects of exposure to any hazardous
substance depend on the dose, the duration, how you are exposed,
personal traits and habits, and whether other chemicals are
present. For more information, call the ATSDR Information
Center at 1-888-422-8737.
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This statement was prepared to give you
information about gasoline and to emphasize the human health
effects that may result from exposure to it. The Environmental
Protection Agency (EPA) has identified 1,397 sites on its
National Priorities List (NPL). Gasoline has been found
in at least 23 of these sites. However, we do not know
how many of the 1,397 NPL sites have been evaluated for gasoline.
As EPA evaluates more sites, the number of sites at which
gasoline is found may change. This information is important
for you to know because gasoline may cause harmful health
effects and because these sites are potential or actual sources
of human exposure to gasoline.
When a chemical is released from a large
area, such as an industrial plant, or from a container, such
as a drum or bottle, it enters the environment as a chemical
emission. This emission, which is also called a release,
may lead to exposure. You can be exposed to a chemical
only when you come into contact with the chemical. You
may be exposed to it in the environment by breathing, eating,
or drinking substances containing the chemical or from skin
contact with it.
If you are exposed to a hazardous chemical
such as gasoline, several factors will determine whether harmful
health effects will occur and what the type and severity of
those health effects will be. These factors include
the dose (how much), the duration (how long), the route or
pathway by which you are exposed (breathing, eating, drinking,
or skin contact), the other chemicals to which you are exposed,
and your individual characteristics such as age, sex, nutritional
status, family traits, lifestyle, and state of health.
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1.1
What is gasoline? |
Gasoline is a complex manufactured mixture
that does not exist naturally in the environment. However,
for the most part, chemicals that are in gasoline are generally
present in several physical states (gaseous, liquid, or others)
in human settlements. Gasoline is produced from petroleum
in the refining process. The gasoline discussed in this
profile is automotive gasoline used as a fuel for engines
in automobiles and other vehicles. Aviation gasoline
and other types of fuels, such as diesel and jet fuels, fuel
oils, and products that result when gasoline is burned, are
not discussed in this profile. The ATSDR toxicological
profiles on jet fuels, Otto Fuels II, and fuel oils have further
information on other types of fuels.
Typically, gasoline contains more than
150 chemicals including small amounts of benzene, toluene,
xylene, and sometimes lead. How the gasoline is made
determines which chemicals are present in the gasoline mixture
and how much of each is present. The actual composition
varies with the source of the crude petroleum, the manufacturer,
and the time of year. Gasoline is a colorless, pale
brown, or pink liquid. Gasoline is very flammable; it
catches on fire quite easily, evaporates quickly, and forms
explosive mixtures with air. Most people can begin to
smell gasoline at 0.25 parts of gasoline per million parts
of air (ppm). Gasoline may be present in the air, groundwater,
and soil. Gasoline does not dissolve readily in water.
However, some of the chemicals that make up gasoline can dissolve
easily in water.
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1.2
What happens to gasoline when it enters the environment? |
Gasoline is a mixture of many different
chemicals. Small amounts of these chemicals evaporate
into the air when you fill the gas tank in your car or when
gasoline is accidentally spilled onto surfaces and soils or
into surface waters. Other chemicals in gasoline dissolve
in water after spills to surface waters or underground storage
tank leaks into the groundwater. The movement of individual
chemicals in gasoline is influenced by physical and chemical
properties, such as how easily they dissolve in water, how
quickly they evaporate, and whether they stick to soil.
In surface releases, most chemicals in gasoline will probably
evaporate; others may dissolve in and be carried away by water;
a few will probably stick to soil. The chemicals that
evaporate are broken down by sunlight and other chemicals
in the air; the completion of this process may take from hours
to weeks. The chemicals that dissolve in water also
break down quickly by natural processes. Most chemicals
in gasoline do not build up to high levels in plants or animals.
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1.3
How might I be exposed to gasoline? |
The most likely way that you might be
exposed to gasoline is by breathing its vapors at a service
station when you are filling your car's fuel tank. If
an attendant fills your car's fuel tank, you may still be
exposed to vapors, but not as much as when you fill it yourself.
If the hose from the gas tank leaks or you overfill your tank,
you may be exposed to more gasoline vapors or some gasoline
may spill on your skin. If you work at a service station,
you will be exposed to more gasoline and its vapors than someone
who just fills the car up occasionally. Air levels as
high as 99 ppm were measured at one gas station during filling
of a car's tank with gasoline. When you use equipment
that runs on gasoline (for example, a lawn mower), you may
be exposed to gasoline or its vapors when you fill the gas
tank (especially when the engine is hot) or operate the machine.
You may also be exposed to gasoline if
you use or drink contaminated water. However, most of
the chemicals in gasoline are usually removed by purification
processes before the water enters drinking water supplies.
Gasoline can seep into groundwater from leaking underground
pipelines or storage tanks. There is no information
on how much gasoline may be in groundwater after a leak, but
in some instances gasoline has been found floating on top
of groundwater that is used to supply drinking water to homes.
According to one estimate, as many as 75,000–100,000 underground
storage tanks leak millions of gallons of gasoline into groundwater
each year. Some of the chemicals making up the gasoline
mix with the water; you would be exposed to these chemicals
when you drink the water, bathe or shower with it, or otherwise
use it.
Another way you might be exposed to gasoline
or its vapors is by being close to a spot where gasoline has
spilled or leaked into the soil. Information on the
amount of gasoline that has seeped into the soil from spills,
storage tanks, or pipelines is not available.
Certain workers have a greater risk of
exposure to gasoline vapors. These include service station
attendants, drivers of gasoline tank trucks, workers at bulk
loading terminals and marine loading docks, workers who remove
and service underground storage tanks and gasoline pipelines,
workers who find and clean up gasoline spills and leaks, and
refinery workers. If you have any of these jobs, you
are probably exposed to small amounts of gasoline vapors every
day you work. If you work at a job using gasoline-powered
equipment or vehicles, you may be exposed to gasoline and
its vapors.
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1.4
How can gasoline enter and leave my body? |
Gasoline can easily enter your body when
you breathe in air or drink water that is contaminated with
gasoline. No information is available on how much gasoline
enters your body when it gets on your skin. When products
like gasoline get on your skin, however, they enter your body
more slowly than when they are taken into your mouth.
Some of the chemicals in gasoline, such as benzene, are expected
to penetrate the skin more easily than some of the other chemicals
in gasoline. Most of the gasoline that you breathe in
or swallow is breathed out unchanged, but some of it can enter
your blood rapidly. Gasoline in your blood travels throughout
your body. When the chemicals in gasoline reach your
liver, they are changed into several different chemical substances.
Most of these new substances travel in your blood until they
reach your kidneys and then leave your body in urine.
However, some of the new substances formed in the liver do
not leave your body as rapidly.
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1.5
How can gasoline affect my health? |
Many of the harmful effects seen after
exposure to gasoline are due to the individual chemicals in
the gasoline mixture, such as benzene and lead in very small
amounts. Inhaling or swallowing large amounts of gasoline
can cause death. The levels of gasoline that killed
people are about 10,000–20,000 ppm when breathed in and about
12 ounces when swallowed. High concentrations of gasoline
are irritating to the lungs when breathed in and irritating
to the lining of the stomach when swallowed. Gasoline
is also a skin irritant. Breathing in high levels of
gasoline for short periods of time or swallowing large amounts
of gasoline may also cause harmful effects on the nervous
system. These effects become more serious as the amount
of gasoline breathed in or swallowed increases. Less
serious nervous system effects include dizziness and headaches,
while more serious effects include coma and the inability
to breathe. Effects on the nervous system have also
occurred in people exposed to gasoline vapors for long periods
of time, either in their jobs or because they intentionally
sniff gasoline for its ability to cause hallucinations.
Harmful effects on the lungs can occur when a person swallows
large amounts of gasoline because the gasoline in the stomach
can enter the lungs during vomiting.
Some laboratory animals that breathed
high concentrations of unleaded gasoline vapors continuously
for 2 years developed liver and kidney tumors. However,
there is no evidence that exposure to gasoline causes cancer
in humans. There is not enough information available
to determine if gasoline causes birth defects or affects reproduction.
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1.6
Is there a medical test to determine whether I have been exposed
to gasoline? |
There are laboratory tests that can determine
if you have been exposed to gasoline. However, these
tests are not generally available in your doctor's office.
The tests involve measuring elevated blood or urine levels
of lead (as an indication of exposure to leaded gasoline only),
benzene, or other substances that may result from exposure
to gasoline or other sources. These methods are sensitive
enough to measure background levels and levels when health
effects may occur. If you have these substances in your
body, however, they may be there as the result of exposure
from sources other than gasoline. Nevertheless, these
tests are useful if exposure to gasoline is suspected.
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1.7
What recommendations has the federal government made to protect
human health? |
The government has developed regulations
and guidelines for gasoline. EPA has established many
regulations to control air pollution. These are designed
to protect the public from the possible harmful health effects
of gasoline. To protect workers, the Occupational Safety
and Health Administration (OSHA) has set a legal limit of
300 ppm for workroom air.
The Occupational Safety and Health Administration
(OSHA) regulates levels of gasoline in the workplace.
The maximum amount of gasoline allowed in workroom air
during an 8-hour workday of a 40-hour workweek is 900 milligrams
of gasoline vapor per cubic meter of air (mg/m³),
or 300 ppm. However, this level is not intended to be
used as a standard for pollutants outside the workplace.
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1.8 Where can I get more information? |
If you have any more questions or concerns, please contact
your community or state health or environmental quality department or:
Agency for Toxic Substances and Disease Registry
Division of Toxicology
1600 Clifton Road NE, Mailstop F-32
Atlanta, GA 30333
Information line and technical assistance:
Phone: 888-422-8737
FAX: (770)-488-4178
ATSDR can also tell you the location of occupational and environmental health
clinics. These clinics specialize in recognizing, evaluating, and treating illnesses
resulting from exposure to hazardous substances.
To order toxicological profiles, contact:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Phone: 800-553-6847 or 703-605-6000
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References |
Agency for Toxic Substances and Disease
Registry (ATSDR). 1995. Toxicological
profile for automotive gasoline. Atlanta, GA: U.S. Department
of Health and Human Services, Public Health Service.
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