1945 –    U.S. Patent No 2,390,941 is issued for 2,4-D to plant physiologist Dr. Franklin D. Jones of the American Chemical Paint Company.
1964 –    54 million pounds of 2,4-D produced as farmers and homeowners alike discover the benefits of effective weed control. Studies at the time found that weeds typically destroyed 30 – 35 percent of crop yields.
1970 –    Plant scientists continue to find new uses for 2,4-D in protecting crops, such as plant growth regulator on potatoes and weed control for blueberries, cranberries, raspberries and strawberries.
1986 –    EPA issues preliminary notification of Special Review.
1988 –    Beginning of reregistration data development by the 2,4-D Task Force and review by EPA.
1996 –    World Health Organization completes its toxicological review of 2,4-D and determines the compound does not present a risk to human health.
2001 –    European Commission completes its toxicological and environmental assessment of 2,4-D and states “. . .that the plant protection products containing 2,4-D will fulfill the safety requirements laid down in the Directive 91/414/EEC.”
2004 –    The Henry Ford organization in Dearborn, Michigan declares 2,4-D one of the 75 most important innovations in the previous 75 years.
2005 –    Health Canada’s Pest Management Regulatory Agency (PMRA) issues “Proposed Acceptability for Continued Registration” and determines 2,4-D can be used safely on lawn and turf when label directions are followed.
2005 –    EPA releases 2,4-D Reregistration Eligibility Decision (RED). EPA’s review of human health and environmental data concludes that the use of 2,4-D does not pose an unacceptable risk to human health when product instructions are followed.
2007 –    EPA determines the existing data do not support a conclusion that links human cancer to 2,4-D exposure and issues “Decision Not to Initiate a Special Review” after more than 21 years of research and agency review.
2008 –    PMRA issues final re-evaluation decision on 2,4-D and determines it is safe to use according to label directions.
2012 –    EPA rejects NRDC petition: “. . . the Agency concluded that the science behind our current ecological and worker risk assessments for 2,4-D is sound and there is no basis to change the registrations.”