New Safety Measures for Herbicide Paraquat

By Amit Jhala and Jennifer Weisbrod

Paraquat is applied annually to control weeds and invasive plants before planting or after harvest in several crops — including cotton, corn and soybeans. Paraquat is also applied as a desiccant and defoliant in a number of crops. 

As a non-selective contact herbicide, it is also applied to terminate crops and provides quick killing of vegetation through immediate contact and translocation within the plant. Paraquat is a valuable crop protection tool and immediate alternatives are not currently available. Because paraquat products are Restricted Use Products, they can only be applied by certified pesticide applicators.

The United States Environmental Protection Agency (EPA) evaluates pesticide registrations on a regular basis but it has taken a proactive approach to this process to ensure Paraquat is used according to the label. This includes a campaign driven by the EPA to promote safety awareness. Additional steps have been taken, including label changes and updates to product packaging that end unsafe and improper use of the product, which have previously caused poisonings and death. Additional training that is specialized for applicators that wish to purchase or use paraquat was provided to ensure the correct use of this herbicide.

The U.S. EPA is proposing new measures to reduce risks associated with paraquat in order to protect human health and the environment. These measures include:

• Prohibiting aerial application for all uses and use sites except cotton desiccation.
• Prohibiting pressurized handgun and backpack sprayer application methods on the label.
• Limiting the maximum application rate for alfalfa to one pound of active ingredient per acre.
• Requiring enclosed cabs if area treated in 24-hour period is more than 80 acres.
• Requiring enclosed cabs or PF10 respirators if area treated in 24-hour period is 80 acres or less.
• Requiring a residential area drift buffer and 7-day restricted entry interval (REI) for cotton desiccation.
• Requiring a 48-hour REI for all crops and uses except cotton desiccation.
• Adding mandatory spray drift management label language.
• In addition, U.S. EPA is proposing to allow truck drivers who are not certified applicators to transport paraquat when certain conditions are met.