- What are naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
- What happens to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene when they enter the environment?
- How might I be exposed to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
- How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene enter and leave my body?
- How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene affect my health?
- How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene affect children?
- How can families reduce the risk of exposure to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
- Is there a medical test to determine whether I have been exposed to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
- What recommendations has the federal government made to protect human health?
- Where can I get more information?
Public Health Statement for Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene
Spanish: Naftalina, 1-Metilnaftalina y 2-Metilnaftalina
CAS#: Naphthalene 91-20-3; 1-Methylnapthalene 90-12-0; 2-Methylnapthalene 91-57-6
PDF Versionpdf icon[153 KB]
This Public Health Statement is the summary chapter from the Toxicological
Profile for Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene.
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 1-800-232-4636.
This public health statement tells you
about naphthalene, 1 methylnaphthalene, and 2 methylnaphthalene
and the effects of exposure to these chemicals.
The Environmental Protection Agency (EPA)
identifies the most serious hazardous waste sites in the nation.
These sites are then placed on the National Priorities List
(NPL) and are targeted for long-term federal clean-up activities.
Naphthalene, 1 methylnaphthalene, and 2 methylnaphthalene
have been found in at least 654, 36, and 412, respectively,
of the 1,662 current or former NPL sites. Although the total
number of NPL sites evaluated for these substances is not
known, the possibility exists that the number of sites at
which naphthalene, 1 methylnaphthalene, and 2 methylnaphthalene
are found may increase in the future as more sites are evaluated.
This information is important because these sites may be sources
of exposure and exposure to these substances may harm you.
When a substance is released either from
a large area, such as an industrial plant, or from a container,
such as a drum or bottle, it enters the environment. Such
a release does not always lead to exposure. You can be exposed
to a substance only when you come in contact with it. You
may be exposed by breathing, eating, or drinking the substance,
or by skin contact.
If you are exposed to naphthalene, 1
methylnaphthalene, or 2 methylnaphthalene, many factors will
determine whether you will be harmed. These factors include
the dose (how much), the duration (how long), and how you
come in contact with them. You must also consider any other
chemicals you are exposed to and your age, sex, diet, family
traits, lifestyle, and state of health.
What are naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
Naphthalene is a white solid that evaporates
easily. It is also called mothballs, moth flakes, white tar,
and tar camphor. When mixed with air, naphthalene vapors easily
burn. Fossil fuels, such as petroleum and coal, naturally
contain naphthalene. Burning tobacco or wood produces naphthalene.
The major commercial use of naphthalene is to make other chemicals
used in making polyvinyl chloride (PVC) plastics. The major
consumer products made from naphthalene are moth repellents,
in the form of mothballs or crystals, and toilet deodorant
blocks. It is also used for making dyes, resins, leather tanning
agents, and the insecticide carbaryl.
Naphthalene has a strong but not unpleasant
smell. Its taste is unknown, but it must not be unpleasant
since children have eaten mothballs and deodorant blocks.
You can smell naphthalene in the air at a concentration of
84 parts naphthalene per one billion parts (ppb) of air. You
can smell it in water when 21 ppb are present.
1 Methylnaphthalene is a naphthalene-related
compound that is also called alpha methylnaphthalene. It is
a clear liquid. Its taste and odor have not been described,
but you can smell it in water when only 7.5 ppb are present.
Another naphthalene-related compound,
2 methylnaphthalene, is also called beta methylnaphthalene.
It is a solid like naphthalene. The taste and odor of 2 methylnaphthalene
have not been described. Its presence can be detected at a
concentration of 10 ppb in air and 10 ppb in water.
1 Methylnaphthalene and 2 methylnaphthalene
are used to make other chemicals such as dyes, and resins.
2 Methylnaphthalene is also used to make vitamin K. All three
chemicals are present in cigarette smoke, wood smoke, tar,
asphalt, and at some hazardous waste sites.
What happens to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene when they enter the environment?
Naphthalene enters the environment from
industrial uses, from its use as a moth repellent, from the
burning of wood or tobacco, and from accidental spills. Naphthalene
at hazardous waste sites and landfills can dissolve in water
and be present in drinking water. Naphthalene can become weakly
attached to soil or pass through the soil particles into underground
Most of the naphthalene entering the
environment is from the burning of woods and fossil fuels
in the home. The second greatest release of naphthalene is
through the use of moth repellents. Only about 10% of the
naphthalene entering the environment is from coal production
and distillation. Less than 1% of the naphthalene released
to the atmosphere can be attributed to the losses from naphthalene
production. Cigarette smoking also releases small amounts
of naphthalene into the air.
Naphthalene evaporates easily. That is
why you can smell mothballs. In the air, moisture and sunlight
make it break down, often within 1 day. Naphthalene can change
to 1 naphthol or 2 naphthol. These chemicals have some of
the toxic properties of naphthalene. Some naphthalene will
dissolve in water in rivers, lakes, or wells. Naphthalene
in water is destroyed by bacteria or evaporates into the air.
Most naphthalene will be gone from water in rivers or lakes
within 2 weeks.
Naphthalene binds weakly to soils and
sediments. It easily passes through sandy soils to reach underground
water. In soil, some microorganisms break down naphthalene.
When near the surface of the soil, naphthalene will evaporate
into air. Microorganisms present in the soil will break down
most of the naphthalene in 1-3 months.
Naphthalene does not accumulate in the
flesh of animals and fish that you might eat. If dairy cows
are exposed to naphthalene, some naphthalene will be in their
milk; if laying hens are exposed, some naphthalene will be
in their eggs. Naphthalene and the methylnaphthalenes have
been found in very small amounts in some samples of fish and
shellfish from polluted waters.
Scientists know very little about what
happens to 1 methylnaphthalene and 2 methylnaphthalene in
the environment. These compounds are similar to naphthalene
and should act like it in air, water, or soil.
How might I be exposed to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
You are most likely to be exposed to
naphthalene, 1 methylnaphthalene, or 2 methylnaphthalene from
the air. Outdoor air contains low amounts of these chemicals.
Burning of wood or fossil fuels and industrial discharges
adds these chemicals to the environment. Automobile exhaust
contributes naphthalene among other chemicals to air pollution
in the cities. Typical air concentrations for naphthalene
are low, 0.2 ppb or less. Studies of outdoor air reported
concentrations of 0.09 ppb 1 methylnaphthalene and 0.011 ppb
2 methylnaphthalene. In homes or businesses where cigarettes
are smoked, wood is burned, or moth repellents are used, the
levels of naphthalene, 1 methylnaphthalene, and 2 methylnaphthalene
in the air are higher. Studies of indoor air typically report
that average indoor air concentrations of these contaminants
are less than 1 ppb.
You are not likely to be exposed to naphthalene,
1 methylnaphthalene, or 2 methylnaphthalene by eating foods
or drinking beverages. These materials are unlikely to come
in contact with naphthalene or methylnaphthalenes during production
or processing. Naphthalene and the methylnaphthalenes are
also unlikely to be present in tap water.
If you live near a hazardous waste site
and have a well used for drinking water, you might be exposed
to naphthalene, 1 methylnaphthalene, or 2 methylnaphthalene.
For this to happen, the chemicals must pass through the soil
and dissolve in the underground water that supplies your well.
Children might also contact these chemicals by playing in
or eating the dirt near a waste site.
Work using or making moth repellents,
coal tar products, dyes, or inks could expose you to naphthalene,
1 methylnaphthalene, and 2 methylnaphthalene in the air. Working
in the wood-preserving, leather tanning, or asphalt industries
could expose you to naphthalene.
Using moth repellents containing naphthalene
in your home will expose you to naphthalene vapors. Your skin
can come in contact with naphthalene via the use of naphthalene-treated
clothing, blankets, or coverlets. You can breathe in the naphthalene
vapors that are present in clothes and linen stored with moth-balls.
Smoke from cigarettes can also expose you to naphthalene,
1 methylnaphthalene, or 2 methylnaphthalene. The highest airborne
naphthalene concentrations in indoor air occur in the homes
of cigarette smokers.
How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene enter and leave my body?
Naphthalene, 1 methylnaphthalene, or
2 methylnaphthalene can enter your body if you breathe air
that contains these chemicals, if you smoke, if you eat mothballs,
if you drink water that contains these chemicals, or if they
touch your skin. These chemicals are most likely to enter
your body through the air you breathe into your lungs. Naphthalene
can also enter your body through your skin when you handle
mothballs, particularly if you have used an oil-based skin
lotion. You can also breathe in naphthalene vapors from clothes
that have been stored in mothballs.
Once naphthalene, 1 methylnaphthalene,
or 2 methylnaphthalene enter your body, small amounts will
dissolve in your blood. Your blood carries them to your liver
and other organs. These organs change them so that they pass
through your body, mainly into your urine. Some naphthalene,
1 methylnaphthalene, or 2 methylnaphthalene, and their breakdown
products can be present in your stool. Naphthalene also has
been found in some samples of fatty tissue and breast milk
taken from the general U.S. population, but the concentrations
of naphthalene were low. Most naphthalene, 1 methylnaphthalene,
or 2 methylnaphthalene that enters your body is expected to
leave quickly within 1-3 days.
How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene affect my health?
Scientists use many tests to protect
the public from harmful effects of toxic chemicals and to
find ways for treating persons who have been harmed.
One way to learn whether a chemical will
harm people is to determine how the body absorbs, uses, and
releases the chemical. For some chemicals, animal testing
may be necessary. Animal testing may also help identify health
effects such as cancer or birth defects. Without laboratory
animals, scientists would lose a basic method for getting
information needed to make wise decisions that protect public
health. Scientists have the responsibility to treat research
animals with care and compassion. Scientists must comply with
strict animal care guidelines because laws today protect the
welfare of research animals.
Exposure to a large amount of naphthalene
may damage or destroy some of your red blood cells. This could
cause you to have too few red blood cells until your body
replaces the destroyed cells. This problem is called hemolytic
anemia. People, particularly children, have developed this
problem after eating naphthalene-containing mothballs or deodorant
blocks. Anemia has also occurred in infants wearing diapers
that have been stored in mothballs. If your ancestors were
from Africa or Mediterranean countries, naphthalene may be
more dangerous to you than to people of other origins. These
populations have a higher incidence of problems with an enzyme
that usually protects red blood cells from damage created
by oxygen in the air.
Some of the symptoms that occur with
hemolytic anemia are fatigue, lack of appetite, restlessness,
and a pale appearance to your skin. Exposure to a large amount
of naphthalene, such as by eating mothballs, may cause nausea,
vomiting, diarrhea, blood in the urine, and a yellow color
to the skin. If you have these symptoms, you should see a
Anemia is a common condition in pregnancy
that can be due to causes other than naphthalene exposure.
However, if you are a pregnant woman and are anemic due to
naphthalene exposure, then it is possible that your unborn
child may be anemic as well. Naphthalene can move from your
blood to your baby's blood. Once your baby is born, naphthalene
may also be carried from your body to your baby's body through
your milk. It is not completely clear if naphthalene causes
reproductive effects in animals; most evidence says that it
Laboratory rabbits, guinea pigs, mice,
and rats sometimes develop cataracts (cloudiness) in their
eyes after swallowing naphthalene at high dose levels. It
is not certain whether cataracts also develop in humans exposed
to naphthalene, but the possibility exists.
When mice or rats breathed in naphthalene
vapors daily throughout their lives (2 years), cells in the
lining of their noses or lungs were damaged. Some exposed
female mice also developed lung tumors. Some exposed male
and female rats developed nose tumors. When mice or rats were
fed naphthalene in their food for 13 weeks, no tumors or other
tissue changes were found. The only effect found was decreased
body weight in rats that were fed naphthalene.
Based on these results from animal studies,
the U.S. Department of Health and Human Services concluded
that naphthalene is reasonably anticipated to be a human carcinogen.
The International Agency for Research on Cancer (IARC) concluded
that naphthalene is possibly carcinogenic to humans, because
there is enough evidence that naphthalene causes cancer in
animals, but not enough evidence about such an effect in humans.
Under the EPA 1986 cancer guidelines, naphthalene was assigned
to Group C - possible human carcinogen.
When mice were fed food containing 1
methylnaphthalene or 2 methylnaphthalene for most of their
lives (81 weeks), the gas-exchange part of the lungs of some
mice became filled with an abnormal material. This type of
lung injury is called pulmonary alveolar proteinosis. A few
mice also had lung tumors, but the numbers of mice with lung
tumors were not enough to conclude that 1 methylnaphthalene
or 2 methylnaphthalene caused the tumors. Pulmonary alveolar
proteinosis has been seen in some people, but the cause of
this uncommon lung disease in humans is unknown.
How can naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene affect children?
This section discusses potential health
effects in humans from exposures during the period from conception
to maturity at 18 years of age.
Hospitals have reported many cases of
hemolytic anemia in children, including newborns and infants,
who either ate naphthalene mothballs or deodorant cakes or
who were in close contact with clothing or blankets stored
in naphthalene mothballs. Newborns or infants are thought
to be especially susceptible to this effect on the blood,
because their bodies are less able to get rid of naphthalene
Newborn mice appear to be more susceptible
to lung injury than adult mice, when they are injected with
naphthalene. These results suggest that children may be more
susceptible to lung injury from naphthalene than adults. Scientists
do not know if lung injury from breathing in naphthalene in
childhood may lead to lung disease later in life.
There are no reports that prenatal or
postnatal exposure to naphthalene has caused developmental
problems in human offspring. When pregnant mice, rats, or
rabbits were fed naphthalene during their pregnancy, the development
of their offspring was normal. Normal offspring development
occurred even when the amounts of naphthalene given were large
enough to prevent the pregnant animals from gaining their
normal amount of weight.
There are no studies in humans or animals
indicating whether or not children are more susceptible to
health effects from 1 methylnaphthalene or 2 methylnaphthalene.
How can families reduce the risk of exposure to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
If your doctor finds that you have been
exposed to substantial amounts of naphthalene, 1 methylnaphthalene,
and 2 methylnaphthalene, ask whether your children might also
have been exposed. Your doctor might need to ask your state
health department to investigate.
The most important way that families
can reduce the risk of exposure to naphthalene, 1 methylnaphthalene,
or 2 methylnaphthalene is to avoid smoking tobacco, generating
smoke during cooking, or using fireplaces or heating appliances
in their homes. If families use naphthalene-containing moth
repellants, the material should be enclosed in containers
that prevent vapors from escaping. The containers should not
be accessible to young children. Blankets and clothing stored
with naphthalene moth repellents should be aired outdoors
to remove naphthalene odors and washed before they are used.
To further minimize the risk of exposure to naphthalene, families
should inform themselves of the contents of air deodorizers
that are used in their homes, and refrain from using deodorizers
Is there a medical test to determine whether I have been exposed to naphthalene, 1-methylnaphthalene, and 2-methylnaphthalene?
Several tests determine whether you
have been exposed to naphthalene, 1 methylnaphthalene, or
2 methylnaphthalene. These tests include measuring naphthalene,
1 methylnaphthalene, 2 methylnaphthalene, or their breakdown
products in samples of urine, stool, blood, maternal milk,
or body fat. These tests require special equipment, which
is not routinely available in a doctor's office. Body fluids,
urine, stool samples, or tissue samples can be sent to a special
laboratory for the tests. These tests cannot determine exactly
how much naphthalene, 1 methylnaphthalene, or 2 methylnaphthalene
you were exposed to or predict whether harmful effects will
occur. If the samples are collected within a day or two of
exposure, then the tests can show if you were exposed to a
large or small amount of naphthalene, 1 methylnaphthalene,
or 2 methylnaphthalene.
What recommendations has the federal government made to protect human health?
The federal government develops regulations
and recommendations to protect public health. Regulations
can be enforced by law. The EPA, the Occupational Safety and
Health Administration (OSHA), and the Food and Drug Administration
(FDA) are some federal agencies that develop regulations for
toxic substances. Recommendations provide valuable guidelines
to protect public health, but cannot be enforced by law. The
Agency for Toxic Substances and Disease Registry (ATSDR) and
the National Institute for Occupational Safety and Health
(NIOSH) are two federal organizations that develop recommendations
for toxic substances.
Regulations and recommendations can be
expressed as "not-to-exceed" levels, that is, levels
of a toxic substance in air, water, soil, or food that do
not exceed a critical value that is usually based on levels
that affect animals; they are then adjusted to levels that
will help protect humans. Sometimes these not-to-exceed levels
differ among federal organizations because they used different
exposure times (an 8-hour workday or a 24-hour day), different
animal studies, or other factors.
Recommendations and regulations are also
updated periodically as more information becomes available.
For the most current information, check with the federal agency
or organization that provides it. Some regulations and recommendations
for naphthalene, 1 methylnaphthalene, and 2 methylnaphthalene
include the following:
The federal government has developed
regulations and advisories to protect individuals from the
possible health effects of naphthalene in the environment.
OSHA set a limit of 10 parts per million (ppm) for the level
of naphthalene in workplace air over an 8 hour workday. NIOSH
set a limit of 500 ppm for the level of naphthalene in workplace
air expected to be immediately dangerous to life or health.
Exposure to workplace air concentrations above this limit
for more than 30 minutes would be expected to impair a worker's
ability to escape the contaminated workplace.
EPA recommends that children not drink
water with over 0.5 ppm naphthalene for more than 10 days
or over 0.4 ppm for any longer than 7 years. Adults should
not drink water with more than 1 ppm for more than 7 years.
For water consumed over a lifetime (70 years), EPA suggests
that it contain no more than 0.1 ppm naphthalene.
Industrial releases of naphthalene into
the environment of more than 100 pounds must be reported to
There are no regulations or advisories
for 1 methylnaphthalene or 2 methylnaphthalene.
Agency for Toxic Substances and Disease Registry (ATSDR). 2005. Toxicological profile for Naphthalene, 1-Methylnaphthalene, and 2-Methylnaphthalene. Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service.
Where can I get more information?
If you have questions or concerns, please contact your community or state health or environmental quality department or:
For more information, contact:
Agency for Toxic Substances and Disease Registry
Division of Toxicology and Human Health Sciences
4770 Buford Highway
Chamblee, GA 30341-3717
Phone: 1-800-CDC-INFO 888-232-6348 (TTY)
Email: Contact CDC-INFO
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.