Registered as a U.S. pesticide in 1993. Reregistered in 2006. Currently under registration review.


Chlorpyrifos-methyl is used in the United States.

Geographic usage data for chlorpyrifos-methyl is not available.

See detailed maps of usage by state and county for other organophosphate pesticides.

Human Health Effects

Even at low levels of exposure, chlorpyrifos-methyl can lead to serious negative health effects.

Neurodevelopmental Harm

High Risk Exposure Routes

People are exposed to chlorpyrifos-methyl through food and drinking water, even if they don’t live near areas where pesticides are sprayed. Details.

Food and/or Drinking Water

Pesticide HandlersPeople involved in pesticide application process. Details.

High Residue Foods

Where residue levels of chlorpyrifos-methyl exceeded allowable limits or were not legally allowed to have residues. Details.

[No high residue foods were specifically identified]

No detection does not necessarily mean there are no residues of concern. A relatively small sample of food products is tested and not all organophosphate pesticides are tested for.

Moreover, current U.S. pesticide tolerance levels are not protective against neurodevelopmental harm in children, so detections at or below tolerance levels do not indicate no harm.

Registered Uses

Where EPA allows chlorpyrifos-methyl to be used.


Grain Sees

Grain Storage Facilities

Additional Information

U.S. Tolerances Categories & Commodities for Chlorpyrifos-methyl

The U.S. EPA sets maximum residue limits — known as “tolerances” — on the amount of chlorpyrifos-methyl that may remain in and on foods. The tolerance is the residue level that triggers enforcement actions.

Tolerances have been set for chlorpyrifos-methyl for: Agricultural Commodities and Milk Eggs Meat and/or Poultry. Maximum residue limits have been set for chlorpyrifos-methyl by the U.S. EPA for the following commodities:


U.S. EPA Human Health Risk Assessments for Chlorpyrifos-methyl

Human Health Risk Assessments are conducted by the U.S. EPA to estimate the nature and probability of harmful health effects in people who may be exposed to pesticide. They are used to make informed decisions about approving new pesticides and new uses of registered pesticides, and during our regular review of existing pesticides. Read the assessment for chlorpyrifos-methyl.