2,4-Dichlorophenoxyacetic acid, more commonly referred to as 2,4-D, is one of the most widely used herbicides in the world to control weeds in agricultural crops, forests and turf grass as well as invasive species in environmentally sensitive areas.
2,4-D was the first selective herbicide. It controls broadleaf plants (dicots – plants with two seed leaves) and does not harm thin leaf plants (monocots – plants like wheat, corn, rice, and many others).
The EPA states that “2,4-D products can be safely used by following label directions.” https://www.epa.gov/ingredients-used-pesticide-products/24-d
Health Canada’s Pest Management Regulatory Agency (PMRA) has determined that 2,4-D may be used safely according to label directions. With specific regard to use on lawns, the PMRA stated:
“Health Canada has determined that 2,4-D meets Canada’s strict health and safety standards. Risks to homeowners and their children from contact with treated lawns and turf are not of concern.”
The European Food Safety Authority concluded in 2015 that “based on the available data, no chronic or acute concerns were identified for consumers.” The latest reassessment in 2023 confirms this.
No, 2,4-D is not an endocrine disruptor. The Environmental Protection Agency (EPA) has reviewed this in its 2005 decision, and reassessed during its most recent NRDC petition response. In both instances the EPA determined that 2,4-D was not an endocrine disruptor. “No convincing evidence of potential interaction with estrogen, androgen or thyroid pathways,”
This evaluation was last revisited and confirmed by the European Food Safety Authority in 2023 and by the EPA in 2017.
Worldwide, no pesticide regulatory agency classifies 2,4-D as a human or animal carcinogen.
Over 75 years of ongoing research have conclusively shown that the weight of evidence finds no correlation between 2,4-D and cancer.
Homeowners should continue to use herbicides in accordance with label directions and restrict access during and immediately following the application of products containing 2,4 D to maximize its efficiency and limit potential exposure.
Worldwide, no pesticide regulatory agency classifies 2,4-D as a human or animal carcinogen.
Multiple studies, including the 1999 study conducted at the School of Veterinary Medicine at Michigan State University, conclude that there is no correlation between 2,4-D and canine cancer. Regulatory decisions around the world confirm that 2,4-D is not an animal carcinogen.
Homeowners should continue to use herbicides in accordance with label directions and restrict access during and immediately following the application of products containing 2,4 D to maximize its efficiency and limit potential exposure.
No, 2,4-D is not harmful to children when used in accordance with label directions. Specific risk assessments for children, taking into consideration their unique physiology, diets, behaviors and play-habits (including their body weight and hand-to-mouth contact while playing on treated grass), are undertaken before a pesticide is granted a registration in both the United States and Canada.
Yes, 2,4-D is heavily researched. More is known about 2,4-D and how it works than almost any other crop protection tool.
The toxicology database alone exceeds 4,000 peer-reviewed, published studies, plus hundreds of scientific studies that manufacturers of 2,4-D must provide to regulatory agencies throughout the world so registrations of products containing 2,4-D are kept current. There are now more than 160 peer-reviewed, published epidemiologic (human) studies pertinent to 2,4-D. The 2,4-D Research Task Force has taken the additional steps of publishing the research data submitted to regulators in peer-reviewed journals.
Back in 2015, the organization IARC assembled a working group to review a number of compounds including 2,4-D. They voted to classify 2,4-D a ‘2B – Possible’ carcinogen, the same ranking they have given to, among other things, coffee, pickles, and being a hairdresser. The panel concluded, “there is inadequate evidence in humans for the carcinogenicity of 2,4-D” because “epidemiological studies did not find strong or consistent increases in risk of NHL or other cancers in relation to 2,4-D exposure.”
No. EPA has called equating 2,4-D with Agent Orange “an urban myth,” noting that the Agency “cancelled the component of Agent Orange that made it dangerous” 40 years ago. 2,4-D was not the ingredient of concern and EPA “considers it [2,4 D] safe when used according to EPA-approved labeling.”
The most recent research demonstrates that there were no detectable exposures for bystanders who reside in homes of homeowner or commercially treated lawns or for barefoot, barelegged bystanders who actively walked or sat on turf grass for one hour 24 hours after application.
Several researchers at the University of Guelph, in Canada, have completed studies on human exposure to applications of 2,4-D for the Ontario Ministry of the Environment. These studies show the highest observed exposures for homeowners and commercial applicators were well below the lifetime ADI (acceptable daily intake) as established by the World Health Organization.
No, the rapid breakdown of 2,4-D minimizes the potential for movement in soil, and greater than 90 – 95 percent dissipates in the top six inches of soil.
Eventually 2,4-D breaks down to CO2 and is integrated into other carbon compounds in the soil. Any findings of 2,4-D in ground water have been extremely rare. These have been attributed to spot contamination or spills near water wells or unique soil conditions with high rainfall or irrigation shortly following application.
