An organophosphate insecticide used on home
and public lawns, gardens, trees and shrubs, as
well as on cotton and some food crops. Malathion
is also sprayed, aerially, over cities, suburbs
and farmland to control mosquitoes and
Mediterranean fruit flies. Some head lice
treatments may also contain malathion.
Immediate Health Effects
- If SWALLOWED, malathion is Moderately
- If ABSORBED THROUGH SKIN, malathion is
- If INHALED (SNIFFED OR BREATHED IN),
malathion is Slightly Toxic
Longterm or Delayed Health Effects
- This chemical is considered an
Unclassifiable Carcinogen by the World
Health Organization, the U.S. Environmental
Protection Agency, or another agency.
- Neurotoxin = Can harm brain and central
- Suspected Endocrine Disruptor = May
interfere with, mimic or block hormones
- Asthma Trigger
- Can affect the brain and nervous system.
- Immediate effects may include nausea,
dizziness, numbness, tingling sensations,
pinpoint pupils, incoordination, headache,
tremor, nausea, abdominal cramps, sweating,
teary eyes, salivation, blurred vision, slow
- At very high exposures, can cause
respiratory paralysis and death.
- Can cause skin rashes or irritation
(redness, itchy or burning), hives or eye
irritation (redness, tearing, swelling,
- There is some evidence that malathion
can cause cancer, based upon animal studies.
See �Other� section for details.
- Inorganic mercury can be corrosive and
causes burns to skin, eyes, and respiratory
How Exposures Occur
Absorption through the skin
- Children can be exposed by touching
recently treated garden vegetables and
fruits. Surfaces in homes, on playground
equipment, recently treated lawns are other
sources. Lawns and outdoor surfaces
down-wind of farms that have sprayed
malathion may also contain harmful residues.
Lawns and outdoor surfaces may become
contaminated when malathion is applied
aerially. The U.S. EPA considers that there
is a concern for toddlers who may be exposed
after application to lawns or other turf
Lice shampoos containing malathion can be
absorbed through the scalp.
- Children may ingest traces of malathion
in foods that have been treated with it.
Malathion residues have been found on
samples of bell peppers, celery, cherries,
grapes, nectarines, peaches, pears,
raspberries, spinach, and strawberries,
among other foods.
- Children may breathe in malathion while
it is being applied to nearby lawns, gardens
or farms, or aerially for med-fly or
- Children may accidently eat malathion by
putting grass or soil into their mouths, or
by touching contaminated surfaces and
putting fingers in their mouths.
Nearly 17 million pounds of malathion are
applied annually in the U.S., primarily to
control boll weevils on cotton.
Overview of Malathion Risk Assessment.
U.S. Environmental Protection Agency Office of
Pesticide Programs, November 6, 2000.
10,637 cases of malathion-related illness
reported to Poison Control Centers between 1985
Review of Malathion Incident Reports.
U.S. Environmental Protection Agency Office of
Prevention, Pesticides, and Toxic Substances,
August 18, 1998.
After malathion was sprayed aerially in
several counties in Florida in 1998 to control
the Mediterranean fruit fly, 123 people reported
illness that was considered probably or possibly
related to the spraying.
�Surveillance for Acute Pesticide-Related
Illness During the Medfly Eradication Program
Florida, 1998,� Journal of the American
Medical Association Morbidity and Mortality
Weekly Report, Vol. 282, No. 23 (December
How to detect malathion
- There are over 250 products containing
malathion on the market. Read labels to
determine if the pesticide products and lice
shampoos in your home are among them.
You can also find out if malathion is an
ingredient in a pesticide product or lice
shampoo on Pesticide Action Network
- If your district resorts to aerial or
ground spraying near your home for mosquito
or other pest control, contact your local
health department to find out which
chemicals are being used.
- Food: There is no way for parents to
determine exactly how much malathion may be
in their children’s food. You can get a
rough idea of the fruits and vegetables that
may contain malathion from:
The Environmental Working Group’s
Report Card: Pesticides in Produce
Do You Know What You’re Eating? by
Update on Pesticides in Children’s Food
How to minimize exposure to malathion
- Avoid the use of pesticides whenever
possible, especially near children. If you
do have pesticides in your home, keep them
tightly closed and out of the reach of
- Contact your local sanitation department
or hazardous waste disposal program to find
out how to dispose of pesticides properly.
Earth 911 lists hazardous waste disposal
sites by zip code.
- Prevent your home and lawn from becoming
a breeding ground for mosquitoes. Unclog
roof gutters, and remove all sources of
standing water, such as old tires, bird
baths, wading pools, and flowerpots.
How To Keep Mosquitos From Biting for
more tips on preventing and avoiding
- Choose least-toxic pest control methods
for your home garden, lawn and shrubs. Adopt
Integrated Pest Management practices.
- If your area will be sprayed with
malathion (or other chemicals), demand to be
notified at least 24 hours in advance to
keep children, pets and people with asthma
or allergies inside. Close all windows and
doors, and switch off air conditioning
during spraying. Keep laundry or toys
inside. Cover lawn furniture and swingsets,
or rinse them afterwards.
- Buy certified organic foods, which are
grown without synthetic pesticides, when you
10 Fruits and Vegetables to Buy Organic.
Otherwise, wash fruits and vegetables well
and peel them.
- The most effective means of treating
lice is the removal of nits (egg sacks) by
hand. There are anedoctal reports of
success of food-grade oils used to smother
lice and ease the removal of nits. Special
lice combs also aid in lice and nit removal.
Avoid using lice shampoos containing
pesticides, such as malathion, permethrin
and lindane! Shampoos made with enzymes from
natural vegetable extracts are a safe and
effective alternative to toxic pesticides.
The enzymes loosen the “glue” that holds
nits in the hair so that they can be combed
For More information
Books, articles, factsheets and reports
Chemical Watch Factsheet: Malathion.
Beyond Pesticides/National Coalition Against the
Misuse of Pesticides.
Brenner, Loretta. �Malathion,� Journal of
Pesticide Reform, Vol. 12, No. 4 (Winter
Head Lice Information. Harvard School
of Public Health, Updated August 9, 2000.
Rumsey, Kay. "Dealing with Head Lice,"
Journal of Pesticide Reform, Vol. 18, No. 2
Olkowski, William, Sheila Daar, and Helga
Olkowski. Common-Sense Pest Control: Least
Toxic Solutions for Your Home, Garden, Pets, and
Community. Newton, Conn,: Taunton Press,
OVERKILL: Why Pesticide Spraying for West
Nile Virus May Cause More Harm Than Good.
Toxics Action Center and Maine Environmental
Policy Institute, July 2001
Head-lice shampoos can be dangerous,
Consumer Reports (September 2003).
Other government agencies
National Pesticide Information Center
Oregon State University
333 Weniger Hall
Corvallis, OR 97331-6502
U.S. Environmental Protection Agency
Office of Pesticide Programs
Ariel Rios Building
1200 Pennsylvania Ave. NW
Washington DC 20460
Beyond Pesticides/National Coalition Against
the Misuse of Pesticides (NCAMP)
701 E Street SE, Suite 200
Washington, DC 20003
Northwest Coalition for Alternatives to
P.O. Box 1393
Eugene, OR 97440
Pesticide Action Network North America
49 Powell Street, Suite 500
San Francisco, CA 94102
The National Pediculosis Association
P.O. Box 610189
Newton, MA 02461
Pesticide Action Network Pesticide Database
Malathion Medical Research Index
Pesticide Action Network Pesticide Advisor
The cancer-causing potential of malathion has
been debated among U.S. EPA staff and other
scientists. In EPA�s original February 2000 risk
assessment of malathion, the agency classified
malathion as a �likely human carcinogen.� This
status was changed in April 2000, when EPA
downgraded malathion to �suggestive evidence of
carcinogenicity but not sufficient to assess
human carcinogenic potential.� This lesser
regulatory status results in fewer restrictions
on the pesticide�s use.
Several dissenting EPA scientists and scientific
advisors believe that the downgrade of this
classification by EPA was in response to
industry pressure. In order to achieve a lower
status, it is alleged that test data was
manipulated to reflect a lower incidence of
cancer in animals exposed to malathion. The
changed decision did not reflect any new data.
Letter from EPA Senior Toxicologist Dr. Brian
Dementi Concerning Cancer and Non-Cancer
Toxicology Issues. U.S. Environmental
Protection Agency, November 8, 2000.