OPA-87-
014
United States • February
Environmental Protection Agency 1988
Washington DC 20460
Pesticides
OPA-87-014
Termrticides
Consumer
Information
U.S. Environmental Protection Agency
Recion 5, Library {5PL--16)
230 S. Dearborn Sti-ast, Room 1630
Chicago, IL (60604
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Extensive use of chemicals to control termites
began in the late 1940s, following the
registration of chlordane as a pesticide in 1948.
Over the next several years, three additional,
chemically related compounds—heptachlor, aldrin,
and dieldrin—were registered as termite control
pesticides ("termiticides"). All four chemicals were
also registered and used to control other insects in
agriculture and around the home.
By 1983, the U.S. Environmental Protection
Agency (EPA) had cancelled nearly all uses of
chlordane, heptachlor, aldrin, and dieldrin except
for termite control applications. These cancellation
actions were based on evidence that these
chemicals cause cancer in certain laboratory
animals and break down slowly in the
environment. The continued use of these four
compounds for termite control was allowed
because there were no effective alternative
chemicals available at the time of EPA's decisions.
Now, however, effective alternatives for
subterranean termite control are available.
EPA had previously concluded that when
chlordane, heptachlor, aldrin, and dieldrin were
applied correctly for subterranean termite control,
the residents of treated homes would not be
exposed to the pesticide. However, new studies
received in 1987 show that generally most
pesticides used for subterranean termite control
can be found at low levels in the air of properly
treated houses. In some circumstances, air levels
of chlordane, heptachlor, aldrin, or dieldrin may
pose a health risk to occupants.
More details on chlordane, heptachlor, aldrin,
dieldrin, and termiticides in general can be found
in the questions and answers below.
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Q What are chlordane, heptachlor, aldrin, and
dieldrin, and how are they related?
A These four chemicals are pesticides used to kill
subterranean termites. They are organic chemicals
called chlorinated cyclodienes (pronounced
cyclo-rfye-eenz).
Of the cyclodiene termiticides, chlordane is the
most widely used. Other trade names for
chlordane are Gold Crest Termide®, Gold Crest
C-100®, Gold Crest C.I.O.-20®, Chlor-kill®,
Octachlor®, Synklor®, and Topiclore®. Commercial
chlordane products actually contain both
chlordane and heptachlor.
(In this leaflet, we refer to the group—chlordane,
heptachlor, aldrin, and dieldrin—as "cyclodienes,"
rather than repeating the separate chemical
names.)
Q Why are termiticides used?
A Termiticides protect your home from termite
damage. Termites eat wood—in buildings, fence
posts, other wood products, tree roots, and fallen
timber. They can be very destructive. Termites
invade buildings through wood that is close to or
touching the soil, such as wooden porches and
fences. They can also enter through small cracks
or openings in concrete floors and foundations.
Q How are termiticides used?
A Effective chemical control of subterranean
termites requires setting up a chemical barrier
between the building's wood and termites in the
soil. In addition to applying termiticide to the soil
before a house is built, correct treatment may
include:
• Pouring termiticide into a trench dug around
the outside of the house and then backfilling the
trench.
• Injecting termiticide into the soil around the
outside of the house (rodding) or in the inside
perimeter of a crawl space.
• Injecting termiticide into the soil beneath the
house through holes drilled into the building's
foundation or slab.
• Injecting termiticide into holes drilled in
hollow-block walls, allowing the chemical to seep
downward through the hollow areas in the blocks.
Treatment for subterranean termites requires a
large quantity of chemical, special equipment and
application techniques, a knowledge of termite
behavior, and an understanding of the way a
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house is built. Thus, termiticide treatments are
more complicated than treatments for other pests
around the home.
Q Are measures other than extensive chemical
treatment available for termite control?
A Several alternative methods are currently
available to help control termites, and other
alternatives are now under development.
Following are some preventive and remedial
alternatives to chemical termiticide treatment.
Good housekeeping practices: Termite infestations
may be prevented or minimized by such
housekeeping practices as keeping wood
structures (siding, piers, etc.) away from direct
contact with the soil; keeping crawl spaces and
immediate areas surrounding houses free of wood
debris or firewood; and repairing leaky drains,
faucets, gutters, or other faulty fixtures which may
cause water to collect beneath or axound a
foundation. Following new construction, it is
always advisable to remove wood scraps from
around the house before backfill is spread.
Wood treated with borates: Borate-treated wood
may be used to replace damaged wood, or in new
construction. This alternative shows some promise
for the future.
Nematodes: A product containing a certain
nematode worm species that infects termites is
commercially available for termite control in
locations throughout the United States. However,
test data from the U.S. Department of
Agriculture's Forest Products Experiment Station
in Gulfport, Mississippi, have raised questions
about the efficacy of this particular alternative.
Barriers: Commercially available structural barriers
made of steel, copper, or certain plastics can help
block termite access to houses.
Non-wood building materials: Some new houses
are being constructed without wood components
and thus provide no food source for termites.
Bait block: The use of bait blocks—an alternative
that is under development, but not yet
commercially available—would involve the
placement of "traps" (constructed of cellulose and
a termite toxicant) around the perimeter of a
house. Termites, attracted to the cellulose, would
inadvertently consume the toxicant. Possible
toxicants for this purpose include biological
control agents such as antibiotics or growth
regulators.
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Molybdenum: Researchers are in the early stages
of evaluating the efficacy of molybdenum
compounds for termite control. These compounds
kill certain bacteria that play a key role in
providing essential nutrients to termites.
Q How do termiticides get inside houses?
A Vapors of cyclodienes and other termiticides
can enter houses after proper or improper
application.
Proper application: Factors that may contribute
to vapors entering the home include cracks in
concrete floors and walls, floor drains, sumps,
joints, cracks in hollow block walls, and air ducts
(heating, cooling, and ventilation ducts).
Improper application: Indoor contamination can
arise from careless injection of liquid termiticides
directly into the living space of a house, or into air
ducts located in or below the slab. Surface
spraying the soil or the wood in a crawl space'is
illegal in most states. In fact, any indoor surface
spraying of the cydodiene termiticides is an improper
application.
Plenum construction: In this type of
construction, air is circulated without ductwork
through the open area below the house. This
allows chlordane vapors to be drawn out of the
soil and into the air of the house. Many chlordane
labels prohibit application to plenum structures.
Q Once cyclodiene vapors get inside a house,
what happens?
A Chlordane and other cyclodiene vapors tend to
persist inside a house. EPA recently received new
indoor air monitoring studies conducted in homes
properly treated with termiticides. Approximately
90 percent of the homes treated with cyclodienes
had detectable residue levels in the air one year
after treatment. (Dieldrin was not included in
these studies.) These studies also showed that
houses built on slabs (on the surface of the
ground) had lower airborne residue levels than
houses with a basement or a crawl-space.
Basement rooms had the highest levels. Chlordane
has also been found in the soil of treated areas 30
years or more after treatment.
Q Does the existence of cyclodiene vapors inside
my house affect my health?
A Although human exposure to the cyclodienes in
the home may increase the risk of developing
certain health problems, most people who are
exposed are not likely to develop these health
conditions. In fact, the risk to a particular person
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of developing adverse symptoms is low. The
health risks depend on the length of time you are
exposed and the concentration of chemical
involved.
• In humans, exposure to high levels commonly
associated with misuse of the cyclodienes has
produced symptoms like headaches, dizziness,
muscle twitching, weakness, tingling sensations,
and nausea. However, these symptoms may also
indicate a wide variety of illnesses unrelated to
cyclodiene exposure. If you have these symptoms,
you should see your physician.
• EPA also has concerns about long-term damage
to the liver and central nervous system, which
may not produce symptoms you can recognize. In
addition, test results have shown that exposure to
the cyclodienes over a lifetime produces tumors in
laboratory animals. As a result, EPA views the
cyclodienes as probable human carcinogens. These
effects may result from exposure at lower levels
than those likely to result from misuse. EPA
recognizes the uncertainty associated with
inferring human health concerns from animal
studies. However, many scientists believe that
animal tests are the most reliable scientific
evidence now available for estimating human
effects.
EPA also recognizes that each individual's
chances of developing symptoms are low.
However, because of the large numbers of people
exposed to the cyclodienes, the risk is a real one
for a small percentage of the population.
Q How do I know if my house has been treated
with any of the cyclodienes?
A If your house was treated for subterranean
termites prior to 1981, it is likely that chlordane or
one of the other cyclodienes was used. Also, prior
to 1983, these chemicals may have been used in
the interior to control other household insect
pests, such as ants. Although new termiticides
have been developed since 1981, chlordane is still
the most commonly used.
EPA does not inspect homes to determine if
cyclodiene termiticides have been used. Instead,
we recommend that you contact the pest control
company that treated your home, the previous
owner of your home, or its builder.
Q What can I do to improve my indoor air
quality?
A There are several ways to minimize your
exposure to the cyclodienes and other air
pollutants:
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• Increase the circulation of clean air in your
house. When weather permits, periodically open
windows and doors, and use fans to mix the air.
In crawl spaces, clear or add vents and install a
fan to constantly vent crawl space air to the
outside.
• Seal those areas that directly contact treated
soil, using grout, caulk, or sealant. Fill cracks in
basement and ground floors and walls, joints
between floors and walls, and openings around
pipes, drains, and sumps. Periodically check these
areas for signs of new cracks or broken seals since
houses settle over time.
• Install a system that supplies outside air to
appliances like clothes dryers and furnaces that
now draw air from inside the house. Appliances
that use indoor air may actually help draw
chemical vapors from the soil into the house
through walls, floors, and basements.
• Check the condition of ducts in your crawl space
or basement. Use duct tape to seal openings and
joints.
Q Should I have the air in my house tested?
A If you do not suspect misapplication, testing
may be of little value. If your home has been
treated in the last several years, low levels of the
cyclodienes could likely be found. However, these
low air-concentration levels generally would not
warrant corrective actions beyond those suggested
for improving indoor air quality. Additional
preventive measures are expensive, and their
success rate in lowering air concentrations is not
well established for all home construction types
and situations.
If you are still concerned, answering the
following questions may help you to decide
whether to have your air tested:
• Do family members consistently show
symptoms that could be caused by exposure to
pesticides? (Check with your physician first.)
• Are there any obvious, major structural flaws,
like large cracks, in the foundation or basement
near treated soil? Does your basement consistently
leak?
• Do some residents spend almost all of their time
in the basement? For example, do you have
occupied bedrooms in the basement?
Houses with air ducts located in or below the
slab, or in the crawl space, and plenum houses,
are particularly vulnerable to misapplication.
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However, if you have one of these types of
houses, this does not necessarily mean that you
have a misapplication problem.
If you suspect that cyclodienes have been
applied improperly in your home, you should
follow the suggestions for improving air quality
and have your air tested. Indications of
misapplication may include the following:
• The presence of chemical odors inside your
house.
• An increase in such odors when the heating or
cooling system is operating.
• Evidence of a chemical spill, such as puddles or
stains, in your house.
Q How can I have my house tested?
A If you decide to have your house tested, make
sure that the results of such testing are reliable by
having a qualified laboratory collect and analyze
air samples. We recommend that you choose a
laboratory proficient in both indoor air sampling
and pesticide analysis.
This type of sen-ice is generally available only
from commercial laboratories. Costs vary
according to the amount of testing you desire to
have done, but could range from about S50. to
5500. To locate a laboratory in your area, call the
National Pesticide Telecommunications Network
(NPTN) at 1-800-858-7378, or look in the Yellow
Pages under "Laboratories."
When you locate a possible laboratory, ask to
see the company's references and statements of
experience regarding cyclodiene sampling and
analysis.
We recommend that the laboratory use the
general methods described in the EPA Manual of
Analytical Methods for the Analysis of Pesticides in
Human and Environmental Samples, June 1980 (EPA
600/8-80-038). Laboratories can obtain this manual
from: National Technical Information Services,
5285 Port Royal Road, Springfield, Virginia 22161.
Q What do my test results mean?
A In 1982, the National Academy of Sciences
(NAS) published interim guidelines for airborne
levels of certain termitiddes. For example, the
level for chlordane is 5 micrograms per cubic
meter. These NAS guidelines should not be
viewed as critical cut-off points. Additional
corrective action beyond the measures to improve
indoor air quality in homes with air levels at or
below the NAS guideline level is probably not
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warranted even though there is a risk to a small
number of people of developing chronic health
effects.
NPTN (1-800-858-7378) can give you additional
background information on the health risks
associated with a given air level of the
cyclodienes.
Q What further steps can I take to reduce
exposure?
A If you have followed suggestions for improving
indoor air quality, have had the air in your house
tested, and your air sample results are of concern
to you, structural modifications may be useful to
further reduce your exposure to the cyclodienes.
For homes that have been properly treated,
modifications are probably not worth the high
expense. However, for homes with high airborne
levels of cyclodiene residues resulting from
misapplication, building modifications may be
worthwhile. They should be designed on a
case-by-case basis but may include replacing or
relocating air ducts, replacing furnaces or
ventilation systems with air exchangers, and/or
sealing crawl space soil with a layer of concrete.
In cases where the cyclodienes have been
improperly applied, household items may be
contaminated. In these cases, clean or replace
contaminated household items (such as carpets,
carpet pads,'and curtains).
Some authorities have suggested washing
contaminated items several times with ordinary
household detergents. However, information
confirming the effectiveness of cleaning with
detergents is not available. In cases of heavy
contamination, as from a chemical spill, the
National Institute for Occupational Health and
Safety has recommended the use of certain
chemical solvents for surface cleaning. These
solvents can be hazardous when inhaled or
allowed to contact the skin, and they should be
used with caution. For specific information on
these chemical solvents, call NPTN at
1-800-858-7378.
Q How can I find out how to dispose of
unwanted chlordane or other termiticides?
A It is illegal to dump chlordane or other
termiticides into sinks, toilets, storm drains, or
any body of water. Proper disposal is necessary to
prevent damage to fish and wildlife, public water
supplies, and sewage treatment plants.
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Disposal of any unused pesticide or its container
must be done according to both the instructions on the
label and state laws. Some local governments
occasionally sponsor "clean-up days" to help
people dispose of unwanted chemicals and
chemical-contaminated items.
For clarification of label directions, or additional
guidance, call NPTN at 1-800-858-7378, or contact
your state pesticide or environmental control
agency or a hazardous waste representative at the
nearest EPA regional office.
Q What alternative termiticides are available?
A As of October 1987, five alternative
termiticides were registered with EPA:
chlorpyrifos (e.g., Dursbans), permethrin (i.e.,
Torpedo5 and Dragnet5), cypermethrin (i.e.,
Demon5), fenvalerate, and isofenphos (i.e.,
Pryfon 6s, formerly Oftanol 6s). Chlorpyrifos
and isofenphos are organophosphate
pesticides. Permethrin, cypermethrin, and
fenvalerate are synthetic "pyrethroid"
pesticides. EPA has essentially complete health
data bases on all five chemicals and has
concluded that, when used according to label
directions, they do not pose unreasonable risks.
Though effective against termites, none of these
chemicals has the demonstrated persistence of
chlordane, heptachlor, aldrin, and dieldrin.
Q Is EPA planning further regulator}' action on
the cyclodiene termiticides?
A On August 11, 1987, EPA publicly announced
that it is proceeding to cancel all registrations of
aldrin and dieldrin. (Domestic production of both
these chemicals ceased in the 1970s, and product
manufacturers stopped importing these
termiticides into the United States in 1985.)
On the same date, EPA also announced it had
reached an agreement with the major manufacturer
of chlordane and heptachlor (Velsicol Chemical
Co.),which resolved EPA's principal concerns
regarding continued use of these termiticides.
Under the terms of this agreement:
• Velsicol immediately stopped its sales and
distribution of chlordane and heptachlor
termiticides. EPA will permit renewed marketing
of chlordane/heptachlor products—for one or more
specific application methods—only after Velsicol
has conducted air-monitoring studies for each
application method being considered, and only if
such studies demonstrate that no detectable levels
of chlordane/heptachlor are found in houses
experimentally treated by a specific application
method.
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• Velsicol has cancelled those application methods
that pose the greatest potential for misuse, and
those application methods most likely to result in'
detectable indoor levels of chlordane/heptachlor.
Methods that have been cancelled include
applications inside a house or other structure,
treatments using high-pressure injection rodding,
and all applications underneath an existing
structure.
Consumers should be aware of certain
requirements established by EPA on October 1,
1987, governing the sale, distribution, and use of
chlordane/heptachlor products registered by
Velsicol. The following timetable applies to all
Velsicol products that were already in channels of
trade in August 1987, when Velsicol stopped its
own sale and distribution of chlordane and
heptachlor.
Through April 15, 1988, only certified pesticide
applicators (or persons under their direct
supervision) may purchase or use Velsicol
products containing chlordane and heptachlor.
Despite what uses are listed on the label, certified
pesticide applicators may apply Velsicol
chlordane/heptachlor products to existing
structures only in outside, perimeter areas around
homes or other buildings, using only low-pressure
application techniques. Applications to construction
sites (pre-construction treatments) are also
permitted with some additional limitations.
After April 15, 1988, sale, distribution, and use of
chlordane and heptachlor are prohibited.
Chlordane/heptachlor products marketed by other
manufacturers are unaffected by this decision and
may continue to be sold and used.
Q How can I get more information?
A Call NPTN at 1-800-858-7378.
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