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Methyl Parathion

What is methyl parathion?

Methyl parathion, sometimes called "cotton poison," is a chemical pesticide that should be used only in open fields to control insects. Most commonly, it is used on cotton, soybean and vegetable fields. Methyl parathion is not meant to be used inside buildings or homes. Such use is illegal. Methyl parathion is a brownish liquid that turns milky white when mixed with water. It can leave a yellow stain on areas where it has been sprayed and smells like rotten eggs.

Why can methyl parathion only be used outside?

In the open air, sunlight and rain change methyl parathion into harmless byproducts. However, even outside, workers are told to stay out of fields that have been sprayed for 48 hours. Inside buildings or homes, methyl parathion does not break down quickly, particularly when it is sprayed in high concentrations. Also, people are more likely to come in contact with the chemical in their homes than when it is sprayed on a field.

How can a person be exposed to methyl parathion?

Before any chemical can affect your health, it has to get into your body. Although you might have methyl parathion in your home, you might not have been exposed. Contact with methyl parathion usually occurs by touching surfaces that were sprayed with the chemical. This would include areas such as baseboards, kitchen counters, under the sink and any area with yellow stains. A person also can be exposed to methyl parathion by breathing contaminated air—especially right after the chemical is sprayed—or by eating or drinking contaminated food or water.

What kinds of health problems does methyl parathion cause?

In small amounts, methyl parathion can cause headaches, nausea, vomiting, diarrhea and dizziness. Higher levels of exposure can cause tremors, blurred vision or difficult breathing. If you or anyone else in your home has these symptoms, contact your family physician. You also can call the Illinois Poison Center at 800-942-5969.

Not everyone with methyl parathion in their homes will have symptoms. When small amounts of the chemical are in the home or if a person has very limited contact with the pesticide, the person may have no symptoms.

A single small exposure from which a person recovers quickly is not likely to cause delayed or long-term health effects. After a serious exposure, a person might feel ill for several weeks. Long-term human health effects related to methyl parathion exposure have not been demonstrated or reported.

If people think their homes have been sprayed with methyl parathion, what should they do?

Call the U.S. Environmental Protection Agency at 312-353-2192 or the Illinois Department of Public Health at 217-782-5830. If you are having symptoms, contact your physician. Keep children and pets away from areas likely to have been sprayed or where there are visible yellow stains. Do not try to clean any areas you suspect to have been sprayed since that could increase exposure to you and others in the home.

What should I do if the exterminator left any pesticide behind or if I purchased any of it?

Do not use any methyl parathion you have in your home. Do not dispose of it yourself. Keep the container away from children, pets, food and water until it can be picked up. Be sure to wash your hands thoroughly with hot water and soap if you have to move the container to a safe place.