News from CRIS: Trending - Chlorpyrifos

September 6, 2021

What is chlorpyrifos? Why was it used? 

The U.S. Environmental Protection Agency (EPA) defines chlorpyrifos as an organophosphate insecticide, acaricide, and miticide used to control foliage and soil-born insect pests.

In common terms, chlorpyrifos is a pesticide used primarily in agricultural settings to kill pests, like insects, that can impact crop growth (1).

Manufacturers also used chlorpyrifos in cattle ear tags. They infused cattle ear tags with a small amount of chlorpyrifos, which slowly distributed the ingredient over the animal to help control pests (1,2).

Farmers used the ingredient from 1965 until August 2021 (1,2). 


How does chlorpyrifos work?

Farms applied manufacturer-recommended and legally allowed amounts of chlorpyrifos to crops such as corn, soybeans, cotton, and fruit and nut trees.

When pests come into contact with the ingredient on the crop, chlorpyrifos blocks the enzyme acetylcholinesterase. The enzyme is required for controlling messages between nerve cells. Without the enzyme the pest’s nervous system malfunctions, leading to the pest’s death (1,2). 


To continue reading the entire blog post, visit: