APHIS Factsheet

Biotechnology Regulatory Services July 2012

Questions and 

Answers: Dow 

AgroSciences’s 2,4-

D Tolerant Soybean 

(Event DAS-44406-6)

APHIS received a petition from Dow AgroSciences 

(DAS), in August 2011, seeking a determination 

of nonregulated status for soybean DAS-44406-6

developed for tolerance to the herbicides 

2,4-dichlorophenoxyacetic acid (2,4-D), glyphosate 

and glufosinate. 

Q: What is Glyphosate?

A: Glyphosate is a commonly used herbicide used 

to kill weeds. When applied to glyphosate resistant 

crops, its helps control weeds without damaging the 

crop.

Q: What is Glufosinate?

A: Glufosinate is an herbicide that controls perennial 

grasses and weeds. It has been used by farmers in 

the United States since 1993.

Q: What is 2,4-D?

A: 2,4-D is approved for use as a pre-plant or postemergent herbicide to control broadleaf weeds on a 

variety of crop and non-crop sites.

Q. Is 2,4-D safe?

A. Yes, 2,4-D herbicide is approved by the 

Environmental Protection Agency (EPA) to control 

broadleaf weeds on a variety of food/feed sites 

including field, fruit, and vegetable crops. It is also 

registered for use on turf, lawns, rights-of-way, 

aquatic sites, forestry applications, and is used as 

a plant growth regulator in citrus. Residents and 

professional applicators may use 2,4-D on home 

lawns.

Q. How long has 2,4-D been used in agriculture?

A. 2,4-D is the most widely used herbicide in the 

world and third most-used in the United States (after 

atrazine and glyphosate). The herbicide has been 

used by farmers in the United States for more than 60 

years. EPA has approved the use of 2,4-D to control 

weeds on a variety of food and feed sites, including field, 

fruit, and vegetable crops. 

Q: Is 2,4-D Agent Orange?

A: No. Agent Orange was the code name for an 

herbicide mixture of 2,4-D and a related herbicide 2,4,5-

T, used by the U.S. military during the Vietnam War as 

an herbicide and defoliant. After its use in the war, it was 

discovered that the synthesis of 2,4,5-T created a highly 

toxic dioxin contaminant. As a result, 2,4,5-T use was 

phased out of most agricultural applications by 1970, 

and EPA ultimately cancelled all remaining uses in 1985. 

Dioxin levels in currently marketed formulations of 2,4-D, 

on the other hand, are either undetectable or well below 

levels considered safe by EPA.

Q. Has APHIS ever granted nonregulated status for 

soybean variety with tolerance to 2,4-D?

A. No. But, should APHIS ultimately grant nonregulated 

status to DAS-44406-6 soybean, it will be the first 

commercially available soybean variety with improved 

tolerance to 2,4-D.

Q: Has soybean DAS-44406-6 been field tested in the 

U.S.?

A: Yes, it has been field tested in the major soybean 

growing regions of the continental United States as well 

as Puerto Rico. All field tests were conducted under field 

permits, including strict movement controls, granted by 

USDA APHIS.

Q: Why is APHIS making this petition available to the 

public?

A: This first comment period provides the public an 

opportunity to review the petition for nonregulated status 

and provide input that will be considered by APHIS as 

it develops its ensuing environmental assessment and 

plant pest risk assessment. APHIS will accept written 

comments regarding the petition for a determination of 

nonregulated status from interested or affected persons 

for a period of 60 days from the date of the Agency’s 

notice in the Federal Register. 

Q: What is the next step following the comment 

period?

A: After the comment period closes, APHIS will carefully 

consider all written comments received during the 
comment period and any other relevant information; 

any substantive issues identified by APHIS based 

on our review of the petition and our evaluation 

and analysis of comments will be considered in 

the development of the Agency’s environmental 

assessment and plant pest risk assessment. 

Q: Under APHIS’ process, what does the Agency 

do after it prepares its draft assessments?

A: After the Agency prepares these documents, it 

makes them publicly available, providing a second 

30-day opportunity for public input. The Agency then 

carefully reviews comments before any determination 

becomes final. 

For more details on the petition process, go to:

http://www.aphis.usda.gov/biotechnology/pet_proc_

imp_info.shtml

Q. How is EPA involved with this environmental 

review process?

A: The EPA has authority over the use of pesticidal 

substances and plant-incorporated protectants under 

the Federal Insecticide, Fungicide, and Rodenticide 

Act (FIFRA) as amended and the Federal Food, Drug, 

and Cosmetic Act (FFDCA). EPA is currently reviewing 

the information submitted by the applicant to evaluate 

the potential human health and environmental risks 

associated with the proposed use of this product on 

soybeans. EPA will base its decision on the best 

available information, and will thoroughly and carefully 

consider the potential impacts to human health and 

the environment. EPA will ensure there are meaningful 

opportunities for public engagement during the 

evaluation process. 

United States Department of Agriculture • Animal and Plant Health Inspection Service • Safeguarding American Agriculture

USDA is an equal opportunity provider and employer.