NEW: EPA Announces Revocation of All Tolerances for Food and Feed Uses of Chlorpyrifos

In a final rule effective October 29, 2021, the EPA announced that the agency is revoking all tolerances for chlorpyrifos. This has the effect of cancelling its use on food and feed crops. The tolerances for all commodities expire on February 28, 2022. A “tolerance” represents the maximum level of pesticide residue legally allowed in or on raw agricultural commodities and processed foods.

For more information visit: EPA Announces Revocation of All Tolerances for Food and Feed Uses of Chlorpyrifos

NEW: Final Scoping Document for Chlorpyrifos Special Registration Review Posted

Chlorpyrifos is a pesticide widely used in Minnesota to manage a variety of arthropod pests. Chlorpyrifos is also a source of contamination in multiple surface water bodies in Minnesota and can pose a substantial risk to human health and the environment. As of June 2020, 13 surface water bodies in Minnesota were proposed for designation by the Minnesota Pollution Control Agency (MPCA) or designated as impaired by the EPA due to chlorpyrifos water quality standard violations. In 2012, the Commissioner of Agriculture designated chlorpyrifos as a “surface water pesticide of concern.” Chlorpyrifos exposure can lead to acetylcholinesterase (AChE) inhibition and neurodevelopmental effects in humans. Thus, the Commissioner of Agriculture has directed the Pesticide and Fertilizer Management Division to conduct an in-depth special registration review of chlorpyrifos.

The MDA wrote a draft scoping document in collaboration with the Minnesota Pollution Control Agency, Minnesota Department of Health, and the University of Minnesota to define the focus and topics for consideration of the special registration review of chlorpyrifos. The draft scoping document was made available for a 60-day public comment period (from July 20 to September 17, 2020). The MDA received public comments from 11 groups or individuals. They were thoroughly reviewed, and minor revisions were made to the scoping document. The revised, final, scoping document will be used to guide the review. Documents related to the scoping document can be found below.

Questions and/or requests for more information may be emailed to:

Chlorpyrifos is a broad-spectrum insecticide used on agricultural crops, nursery plants, ornamentals, wood structures, cattle, and other habitats in Minnesota. It can also be used in greenhouse and nursery production, wood products, and roach bait stations. Most chlorpyrifos products are restricted use pesticides (RUPs). Applicators must be certified or licensed by the MDA to use products carrying the RUP designation.


Pesticide Type Insecticide (Group 1B)
Chemical Class Organophosphate
Common Trade Names* Warawk, Pilot, Chlorpyrifos 4E AG
Registration Status EPA: Registered since 1965
MN: Registered
diagram of chlorpyrifos chemical structure
*No endorsement is implied in the referencing of trade names.

The MDA created the webinar video “Chlorpyrifos Use in Minnesota” for applicators, farmers, and agricultural professionals which provides information on proper use of chlorpyrifos, label requirements, soybean aphid control, and pyrethroid-resistant soybean aphids.

Chlorpyrifos has been detected in surface waters in Minnesota through the MDA’s Ambient Water Monitoring Program and is currently designated as a “Surface Water Pesticide of Concern.” Select water bodies in the state have also been listed as “impaired” due to elevated detections of chlorpyrifos. The MDA has developed water quality best management practices and increased education and outreach efforts focused on chlorpyrifos.