Methomyl

Methomyl is a carbamate insecticide used to control foliage and soil-borne insect pests on a variety of food and feed crops.

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Basic Information

Methomyl has been used as a pesticide since 1968.

There are no residential uses of methomyl.

Methomyl is used mostly in agriculture, and is currently registered for use on field vegetables like lettuce, orchard crops like oranges, and on turf (sod farms only). Some agricultural uses are being canceled or reduced during 2015.

The only non-agriculture use of methomyl is as fly bait product, which is not a restricted use.

Using Methomyl Products Safely

Methomyl is extremely toxic if ingested and moderately toxic if inhaled. It is a cholinesterase inhibitor in humans at high enough doses; that is, it can overstimulate the nervous system resulting in nausea, dizziness, confusion, and at very high exposures (e.g., accidents or major spills), respiratory paralysis and death.

To minimize health impacts, EPA classified methomyl products used in agricultural settings as “restricted use,” meaning they can be used only by or under the direct supervision of specially trained and certified applicators. Learn more about restricted use pesticides.

Methomyl dissolves in water and breaks down rapidly in soil, so it has a low persistence in the environment.

All registered methomyl products can be safely used by following label directions.

When handling methomyl products, users must follow the safety precautions found on the product label. These include:

  • wearing protective clothing and eyewear at all times;
  • distancing yourself from the chemical when mixing it;
  • using personal protective equipment like a respirator during application; and
  • observing re-entry intervals.

EPA Actions

The following actions are part of EPA’s efforts to reduce carbamate use, which includes methomyl, thereby protecting people’s health, especially the health of children who may be more sensitive to pesticides. From 1995 to 2013, exposures from food to carbamates has fallen by approximately 70%.

In January 2015, manufacturers agreed to voluntarily cancel certain uses of methomyl because of EPA’s estimates of the drinking water risks for the use of methomyl in agricultural settings. Actions taken include:

  • canceling the use of methomyl on barley, oat, and rye; 
  • limiting its use on wheat to Idaho, Oregon, and Washington;
  • reducing the number of applications for corn, celery, and head and leaf lettuce; and
  • reducing the number of applications and the seasonal maximum application rate for peppers.

Also in January 2015, EPA and manufacturers reached an agreement to stop making and selling some fly bait products and to add label language that clarifies the approved uses. EPA believes that these changes will reduce the illegal use of methomyl fly bait products to kill wildlife, an issue that has been reported to EPA by a number of states.

Methomyl is currently undergoing registration review, a program that re-evaluates all pesticides on a 15-year cycle. EPA plans to release methomyl’s draft risk assessment in 2016. All documents related to the registration review can be located in docket number EPA-HQ-OPP-2010-0751 located at www.regulations.gov.

Additional Information

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