The information in this profile may be out-of-date. It was last revised in 1996. EXTOXNET no longer updates this information, but it may be useful as a reference or resource.

Please visit the National Pesticide Information Center (NPIC) to find updated pesticide fact sheets. If you don't find a fact sheet related to your question, feel free to call 1-800-858-7378. NPIC is open five days a week from 8:00am to 12:00pm Pacific Time.


Extension Toxicology Network

Pesticide Information Profiles

A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program.

EXTOXNET primary files maintained and archived at Oregon State University

Revised June 1996


Trade and Other Names: Product names include Crisquat, Cyclone, Dextrone, Dexuron, Gramoxone Extra, Herbaxone, Ortho Weed and Spot Killer, and Sweep. The compound may be found in formulations with many other herbicides, including simazine and diquat dibromide.

Regulatory Status: Paraquat is a highly toxic compound in EPA toxicity class I. Products containing it must be is labeled with the Signal Words DANGER - POISON. Paraquat is a Restricted Use Pesticide (RUP). RUPs may be purchased and used only by certified applicators.

Chemical Class: quaternary nitrogen compound

Introduction: Paraquat is a quaternary nitrogen herbicide widely used for broadleaf weed control. It is a quick-acting, nonselective compound, that destroys green plant tissue on contact and by translocation within the plant. It has been employed for killing marijuana in the U.S. and in Mexico. It is also used as a crop desiccant and defoliant, and as an aquatic herbicide.

Formulation: Not Available

Toxicological Effects:

Ecological Effects:

Environmental Fate:

Physical Properties:

Exposure Guidelines:

Basic Manufacturer:

Zeneca Ag Products
1800 Concord Pike
Wilmington, DE 19897


References for the information in this PIP can be found in Reference List Number 10

DISCLAIMER: The information in this profile does not in any way replace or supersede the information on the pesticide product labeling or other regulatory requirements. Please refer to the pesticide product labeling.