Michigan: New Rules for Using Paraquat

Young weeds emerging in carrot row. Photo: Ben Werling, Michigan State University

Young weeds emerging in carrot row. Photo: Ben Werling, Michigan State University

Paraquat, a nonselective contact herbicide, has been registered many years for managing annual weeds in vegetables and tree fruit. Paraquat is sold under several trade names including Gramoxone, Firestorm and Parazone.



Paraquat can have adverse health effects after ingestion, entry through damaged skin or inhalation. It is acutely toxic when ingested—as little as a teaspoon of concentrated paraquat can result in death. Due to this health risk, the Environmental Protection Agency (EPA) has announced new rules and regulations for making paraquat use safer.

To implement these rules, labels for new formulations of paraquat will include the following requirements.

First, only certified applicators can mix, load and apply paraquat. Uncertified applicators cannot use it, even under the supervision of a certified applicator.

Second, applicators need to take an EPA-approved training every three years.

Finally, containers under 120 gallons will come with “closed-system” packaging. These containers are only to be used with closed-transfer systems. Newly produced paraquat, which will carry these label requirements, will be formulated with 3 pounds active ingredient per gallon compared to the older formulations with 2 pounds active ingredient per gallon.

The online training is very easy, completely free and only takes about 45 minutes with a short quiz. At the end of the training, you will get a certificate with your name that you will need to use paraquat products. This training can be found at U.S. Paraquat Training.

Containers for new product will come with a complete seal and no screw caps, adaptors or other way to open and decant. These containers are for use with a closed transfer system that safely transfers a measureable quantity of product into spray tanks. This system will help prevent spills during pouring of the pesticide that could lead to paraquat exposure.

According to EPA, growers are granted discretion in how they use available technology to adapt sprayers for closed-transfer systems. GoatThroat Pumps, a Milford, CT-based pump designer and manufacturer is one company where growers can find more information about closed transfer systems, which comply with the EPA’s new paraquat use requirements.

Source URL: https://www.canr.msu.edu/news/new-rules-for-using-paraquat-in-2020-and-beyond