Malathion poisoning
Carbofos poisoning; Compound 4049 poisoning; Cythion poisoning; Fosfothion poisoning; Mercaptothion poisoning
Malathion is an insecticide, a product used to kill or control bugs. Poisoning may occur if you swallow malathion, handle it without gloves, or do not wash your hands soon after touching it. Large amounts can be absorbed through the skin.
This article is for information only. DO NOT use it to treat or manage an actual poison exposure. If you or someone you are with has an exposure, call the local emergency number (such as 911) or the local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.
Poisonous Ingredient
Malathion is the poisonous ingredient in these products.
Where Found
Malathion is used in agriculture to kill and control insects on crops and in gardens. Government agencies also use it to kill mosquitoes in large outdoor areas.
Malathion may also be found in certain products used to kill head lice.
Symptoms
Below are symptoms of malathion poisoning in different parts of the body.
AIRWAYS AND LUNGS
- Chest tightness
- Difficulty breathing
- Wheezing
- Increased airway secretions or mucus
- No breathing
BLADDER AND KIDNEYS
- Increased urination
- Inability to control urine flow (incontinence)
EYES, EARS, NOSE, AND THROAT
- Increased salivation
- Increased tears in the eyes
- Small pupils
- In some cases, pupils may be dilated and do not react to light
HEART AND BLOOD
- Low or high blood pressure
- Slow heart rate
- In some cases, heart rate may be rapid
- Weakness
NERVOUS SYSTEM
- Agitation
- Anxiety
- Coma
- Confusion
- Convulsions
- Dizziness
- Headache
- Muscle twitching
SKIN
- Blue lips and fingernails
- Sweating
STOMACH AND GASTROINTESTINAL TRACT
- Abdominal cramps
- Diarrhea
- Loss of appetite
- Nausea and vomiting
Home Care
Call the poison control center for treatment information. If malathion is on the skin, wash the area thoroughly for at least 15 minutes.
Throw away all contaminated clothing. Follow instructions from the appropriate agencies for getting rid of hazardous waste. Wear protective gloves when touching contaminated clothing.
Before Calling Emergency
Have this information ready:
- Person's age, weight, and condition
- Name of the product (ingredients and strength, if known)
- Time it was swallowed
- Amount swallowed
Poison Control
The local poison control center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline will let you talk to experts in poisoning. They will give you further instructions.
This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.
You can also get online poison help now at
What to Expect at the Emergency Room
Take the container with you to the hospital, if possible.
People with malathion poisoning will likely be treated by first responders (firefighters, paramedics) who arrive when you call the local emergency number. These responders will decontaminate the person by removing the person's clothes and washing them down with water. The responders will wear protective gear. If the person is not decontaminated before getting to the hospital, emergency room personnel will decontaminate the person and provide other treatment.
Your health care provider at the hospital will measure and monitor your vital signs, including temperature, pulse, breathing rate, and blood pressure. You may receive:
- Blood and urine tests
- Breathing support, including oxygen, or a tube that goes through the mouth into the lungs, and attachment to a breathing machine (ventilator)
- Chest x-ray
- Head CT (computerized tomography) scan
- Electrocardiogram (ECG)
- Intravenous fluids (fluids given through a vein)
- Medicine to reverse the effects of the poison, which may include atropine or pralidoxime
- Tube placed down the nose and into the stomach (sometimes)
- Washing of the skin (irrigation) and eyes, perhaps every few hours for several days
Outlook (Prognosis)
People who continue to improve in the first 4 to 6 hours after receiving medical treatment usually recover. Prolonged treatment often is needed to reverse the poisoning. This may include staying in the hospital intensive care unit and getting long-term therapy. Some effects of the poison may last for weeks or months, or even longer.
Keep all chemicals, cleaners, and industrial products in their original containers and marked as poison, and out of the reach of children. This will reduce the risk of poisoning and overdose.
References
Agency for Toxic Substances and Disease Registry (ATSDR) website. Toxic substances portal: toxicological profile for malathion.
Aminoff MJ, So YT. Effects of toxins and physical agents on the nervous system. In: Jankovic J, Mazziotta JC, Pomeroy SL, Newman NJ, eds. Bradley and Daroff's Neurology in Clinical Practice. 8th ed. Philadelphia, PA: Elsevier; 2022:chap 86.
Welker KL, Thompson TM. Pesticides. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 152.
Version Info
Last reviewed on: 4/8/2025
Reviewed by: Jesse Borke, MD, CPE, FAAEM, FACEP, Attending Physician at Kaiser Permanente, Orange County, CA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
