Neem oil is a naturally occurring pesticide found in seeds from the neem
tree. It is yellow to brown, has a bitter taste, and a garlic/sulfur smell. It has been used for hundreds of
years to control pests and diseases. Components of neem oil can be found in many products today. These
include
toothpaste,
cosmetics, soaps, and pet shampoos. Neem oil is a mixture of components. Azadirachtin is the most active
component for repelling and killing pests and can be extracted from neem oil. The portion left over is
called
clarified hydrophobic neem oil.
Neem oil and some of its purified components are used in over 100 pesticide products. They are applied to a
wide
variety of crops and ornamental plants for insect control. Neem oil can be formulated
into granules, dust, wettable powders or emulsifiable
concentrates.
IMPORTANT: Always follow label instructions and take steps to minimize exposure. If any exposures occur, be sure to follow the First Aid instructions on the product label carefully. For additional treatment advice, contact the Poison Control Center at 800-222-1222. If you wish to discuss a pesticide problem, please call NPIC at 800-858-7378.
Neem oil is made of many components. Azadirachtin is the most active.
It reduces insect feeding and acts as a repellent. It also interferes
with insect hormone systems, making it harder for insects to grow and lay eggs. Azadirachtin can also repel
and
reduce the feeding of nematodes. Other components of neem oil kill insects by hindering their ability to
feed.
However, the exact role of every component is not known.
People can be exposed to chemicals by eating them, breathing them
in, through skin contact and eye contact. Since neem oil is used on a variety of crops, people are mainly
exposed to
neem oil in their diet. People who apply neem oil may also be exposed if they inhale the mist or dust, let
the
product
touch their skin, or fail to wash their hands before eating or smoking. However, the label includes
directions
for keeping
exposure low. For example the label might require applicators to wear protective clothing.
What are some signs and symptoms from a brief exposure to neem oil?
Neem oil can be slightly irritating to the eyes and skin. Azadirachtin, a component
of neem oil, can be very irritating to the skin and stomach. The remaining portion
of neem oil is made of fatty acids, essential oils and other substances that are commonly
eaten in a normal diet. These substances are generally recognized as safe
(GRAS) by the United States Food and Drug Administration.
In other countries, neem oil has been used on cats for
flea control. Some adverse
reactions have been reported. Symptoms include feeling sluggish, excessive salivation,
impaired movement, trembling, twitching, and convulsions. Some of the cats
died. However, most of them recovered within 1 to 5 days.
Clarified hydrophobic neem oil (without azadirachtin) is made of fatty acids and glycerides. These substances
are
commonly found in food. When they enter the body, they are broken down, used for energy, and incorporated
into
cells.
In one study, scientists injected insects with azadirachtin. They found 90% of the dose in the insects' feces
within 7
hours. The remaining portion lingered in the insects' bodies for 24 days after the injection.
No. People have been exposed to neem oil in many ways for hundreds of years. During this time no association
with
increased cancer risk has been found. Studies showed that neem oil
did not alter or damage genes. In laboratory tests,
animals were fed neem oil for 90 days. They did not have increased cancer rates.
Further, one study found that certain components of neem oil caused cancer cells in hamsters to stop growing
or
die.
Another study looked at prostate cancer cells from humans. Researchers found that neem leaf extract was able
to
slow their growth.
In general, children
may be
especially sensitive to pesticides compared to
adults. When rats were fed neem oil in one
study, their pregnancies ended. In another study, rats were fed azadirachtin in their diet throughout their
lives. No
effects to their offspring were found. Additionally, neem oil is used in toothpaste, cosmetics, soaps and
traditional
medicines around the world. Therefore, people of all ages are commonly exposed to neem oil. No data were
found
to
show that children are more sensitive than adults to neem oil.
What happens to neem oil in the environment?
Azadirachtin, a major component of neem oil, is rapidly broken down.
Microbes and light break down the pesticide in soil, water and on plants.
The half-life
of
azadirachtin
in soil ranges from 3-44 days. In water, the
half-life ranges from 48 minutes to 4 days. It also rapidly breaks down on plant leaves; the half-life
is 1-2.5
days. The remaining components of neem oil are broken down by microbes in most soil and water
environments.
Neem oil is practically non-toxic to birds, mammals, bees and plants.
Neem
oil is
slightly toxic to fish and other aquatic organisms.
Azadirachtin, a component of neem oil, is moderately toxic to fish and other aquatic animals. It is
important to
remember that insects must eat the treated plant to be killed. Therefore, bees and other pollinators are
not
likely to be harmed.
Where can I get more information?
For more detailed information about neem oil please visit the list of referenced
resources or call
the National Pesticide Information Center, Monday - Friday, between 8:00am - 12:00pm Pacific Time
(11:00am -
3:00pm Eastern Time) at 1-800-858-7378 or visit us on the web at
http://npic.orst.edu.
NPIC
provides objective, science-based
answers to
questions about pesticides.
Date Reviewed: March 2012
Please cite as: Bond, C.; Buhl, K.; Stone, D. 2012
Neem Oil General Fact Sheet;
National
Pesticide
Information Center, Oregon State University Extension Services. npic.orst.edu/factsheets/neemgen.html.
References:
Pesticide Product Information System; U.S. Environmental Protection
Agency, U.S.
Government Printing
Office: Washington, DC, 2012.
Neem Oil; Tolerance Exemptions. Fed. Regist. December 13, 1995, 60
(239),
63950-63953.
Azadirachtin Summary Document Registration Review;
EPA-HQ-OPP-2008-0632-0002;
U.S. Environmental
Protection Agency, Office of Pesticide Programs, Biopesticides and Pollution Prevention Division,
U.S.
Government Printing Office: Washington, DC, 2008.
Biopesticides Registration Action Document (BRAD) Cold Pressed Neem
Oil;
EPA-HQ-OPP-2007-0996-0002; U.S.
Environmental Protection Agency, Office of Pesticide Programs, Biopesticides and Pollution
Prevention Division,
U.S. Government Printing Office: Washington, DC, 2009.
Cold Pressed Neem Oil; Exemption from the Requirement of a Tolerance. Fed.
Regist. October 28, 2009, 74
(207), 55458-55463.
Krieger, R. I. Handbook of pesticide toxicology, 2nd ed.; Academic
Press: San
Diego, 2001; pp 130-134.
National Research Council. Neem : a tree for solving global
problems; National
Research Council; National
Academy Press: Washington, DC, 1992; p 141
Reigart, J. R., Roberts, J. R. Recognition and Management of Pesticide
Poisonings, 5th ed.; U.S.
Environmental Protection Agency; Office of Prevention, Pesticides, and Toxic Substances, U.S.
Government
Printing Office: Washington, DC, 1999; p 63
Schmutterer, H. The neem tree : Sources of unique natural products for
integrated pest
management, medicine,
industry, and other purposes; VCH Publishers, Inc.: New York, 1995.
Sutton, N. M.; Bates, N.; Campbell, A. Apparent adverse reactions to neem (margosa) oil in cats.
Vet.
Rec. 2009, 164 (19), 592-593.
Harish Kumar, G.; Vidya Priyadarsini, R.; Vinothini, G.; Vidjaya Letchoumy, P.; Nagini, S. The neem
limonoids
azadirachtin and nimbolide inhibit cell proliferation and induce apoptosis in an animal model of
oral
oncogenesis. Invest. New Drugs 2010, 28 (4), 392-401.
Kumar, S.; Suresh, P. K.; Vijayababu, M. R.; Arunkumar, A.; Arunakaran, J. Anticancer effects of
ethanolic neem
leaf extract on prostate cancer cell line (PC-3). J. Ethnopharmacol.
2006, 105,
246-250.
Srivastava, M. K.; Raizada, R. B., Lack of toxic effect of technical azadirachtin during postnatal
development
of rats. Food Chem. Toxicol. 2007, 45 (3), 465-71.
NPIC fact sheets are designed to answer questions
that
are
commonly
asked by the general public about pesticides that are regulated by the
U.S. Environmental Protection Agency (US EPA). This document is
intended to be educational in nature and helpful to consumers for
making decisions about pesticide use.
