The chemical known as 2,4-D has been around for decades, long before Dow AgroSciences began marketing it as a new weed killer called Enlist Duo in 2014.
Iowa farmer George Naylor recalls using an herbicide containing a potent chemical combination of both dicamba and 2,4-D about forty years ago on his soybean and cotton fields, "because it was the most powerful herbicide you could get.” He remembers seeing the product volatilize into the air, run with water and crinkle the leaves of his soybean plants.
He eventually stopped spraying that herbicide “because all the other herbicides basically made it obsolete.” Since the 1990s, Monsanto’s Roundup herbicide, containing the chemical glyphosate, has taken over as the weed killer of choice on industrial farms, but that’s about to change.
Data that reporters and analysts have obtained from government agencies shows that the spraying of glyphosate herbicides has increased with the planting of soybean and cotton seeds that are genetically modified to resist glyphosate.
That, in turn, has likely led to an epidemic of super-weeds, in which weeds evolve to survive spraying. With super-weeds estimated to wreak havoc on tens of millions of acres of farmland, the agrochemical industry has presented a solution: more potent herbicides. Now, weed killers containing the older chemicals 2,4-D and dicamba are once again being heavily marketed to farmers.
EPA pulls Enlist Duo's approval, but Trump's EPA brings it back
“Take control of weeds like never before,” Dow writes in one online advertisement for Enlist Duo. The herbicide, which is meant to be sprayed on cotton and soybean seeds also developed by Dow, genetically modified to withstand both glyphosate and 2,4-D, was pulled from the market in 2015 after environmental and food safety groups sued the Environmental Protection Agency under the Obama administration.
After a year of litigation, the EPA said it had revoked the registration for Enlist Duo over concerns that it may may be more drift-prone, more potent, and more toxic than previously thought. But the EPA under President Trump decided to give Enlist Duo another chance. In January, the agency approved the marketing of the Enlist herbicide and its accompanying seeds in a total of 34 states.
"From its initial approval in 2014, EPA consistently acknowledged that Enlist Duo will damage crops,” Center for Food Safety staff attorney Sylvia Wu tells ConsumerAffairs. But because it was mostly small farmers who would be affected by the crop damage, the EPA approved Enlist anyway, Wu says. "Unfortunately, with both administrations, the pesticide and chemical industry has been very effective with lobbying at the federal level.”
A coalition of advocacy groups -- the Center for Food Safety, the Pesticide Action Network, Beyond Pesticides, the Center for Biological Diversity, Family Farm Defenders, and the National Family Farm Coalition -- on March 21 filed a new federal lawsuit against the Trump administration for approving Enlist Duo once again. They charge that the EPA violated the Endangered Species Act and other federal laws when approving the Enlist technology in 34 states.
The groups overall object to the increased dependence on herbicides in industrial farming. "Roundup was initially touted as a replacement for older, more dangerous chemicals like 2,4-D,” Jim Goodman, an organic farmer with the group Family Farm Defenders, says in a news release. “Now that Roundup, the widely used carcinogenic pesticide is failing to kill weeds, Dow is bringing back 2,4-D and teaming them up to create a more toxic mix than ever.” (The official stance from federal regulators is that glyphosate is not carcinogenic, but the issue is a matter of intense debate).
Dow did not return an interview request from ConsumerAffairs. “Adding tolerance to a new 2,4-D, the Enlist weed control system advances herbicide and trait technology by building on the glyphosate and glufosinate systems,” Dow tells farmers in online advertising.
Warning label on product meant to assuage concerns
The EPA’s document explaining its reasons for the “Final Registration of Enlist Duo,” included as part of the lawsuit, sometimes reads like a document arguing against the approval of Enlist Duo. “This pesticide is toxic to fish and aquatic invertebrates….Drift or runoff may adversely affect aquatic invertebrates and non-target plants...Application around a cistern or well may result in contamination of drinking water or groundwater...Small amounts of spray drift that may not be visible may injure susceptible broadleaf plants.”
The EPA multiple times describes the risk of drift, or the chemical drifting from its intended target and killing other plants, or worse. “Without considering mitigation measures, it is reasonable to assume spray drift may be a potential source of exposure to residents nearby to spraying operations... Sprays that are released and do not deposit in the application area end up off-target and can lead to exposures to those it may directly contact....residues can eventually lead to indirect exposures (e.g., children playing on lawns where residues have deposited next to treated fields).”
For studies conducted on rats, meant to evaluate the effect that dietary exposure to the herbicide could have on human females of child-bearing age, “fetal skeletal malformations (14th rudimentary ribs) were observed,” the EPA writes. Studies meant to evaluate the effect on the general population found “an increased incidence of incoordination and slight gait abnormalities (forepaw flexing or knuckling) and decreased motor activity.” Inhalation was linked with “increased mixed inflammatory cells within the larynx, which was not totally resolved following a 4-week recovery period.”
"The toxicity profile of the active ingredient 2,4-D shows that the principal toxic effects are changes in the kidney, thyroid, liver, adrenal, eye, and ovaries/testes in the rat following exposure to 2,4-D via the oral route at dose levels above the threshold of saturation of renal clearance,” the EPA says. “Maternal and developmental toxicity were observed at high dose levels exceeding the threshold of saturation of renal clearance.”
But the agency ultimately determined in the same document that the toxic effects only occurred at exposure levels that they estimated were well above what people would likely be exposed to.
"A premise of compliant applications"
More important, according to the EPA, is that a warning label on the product itself should reduce the risk of both drift and toxicity. The EPA writes that its evaluation into the risk of spray drift “is based on a premise of compliant applications which, by definition, should not result in direct exposures to individuals because of existing label language and other regulatory requirements intended to prevent them.”
Following the label, the EPA says, will “reduce exposures off-site to levels well below risk concern levels for both birds and mammals, thereby limiting any potential risks of concern to the treatment site itself.”
The Enlist Duo label instructs farmers not to spray “during a local, low level temperature inversion because drift potential is high.” Farmers are also instructed to avoid spraying if rain is expected in the next 24 hours and to maintain a 30-foot buffer between their field and everything else. “Do not apply under circumstances where spray drift may occur to food, forage, or other plantings that might be damaged or crops thereof rendered unfit for sale, use or consumption,” the label instructs. “Do not apply at wind speeds greater than 15 mph.”
To combat the growing problem of herbicide resistance, particularly concerns that weeds may eventually develop a resistance to 2,4-D, the EPA has put Dow in charge of investigating. Dow AgroSciences “must investigate any reports of lack of herbicide efficacy and submit annual reports to the EPA,” the EPA says. “The initial mechanism users can use for communicating directly with DAS is a toll-free number to get advice on how to resolve any uncontrolled weeds.”
Pushing the limit on labels
George Naylor, the cotton and soybean farmer from Iowa, says that farmers are under so much pressure to keep up with the demands of industrial farming that they often do not follow labels as closely as they should. “I think every farmer has probably pushed the limit on windspeed, because they want to get those weeds sprayed before they get too big,” Naylor tells ConsumerAffairs.
"The cost squeeze gets me and other farmers to do something they know they shouldn't be doing...it's been our national policy for a long time to put farmers in that squeeze.” Additionally, he says, “more and more of the spraying is done by third parties, either the local co-op or a private applicator.” For those and other reasons, he says it has become a very common phenomenon for sprays from neighboring farms to damage another farmer’s crop.
But Naylor counts himself as among the more fortunate. While most farmers work on land that they are renting, and therefore face constant pressure from landlords and competitors, Naylor works on family land that he inherited. As other farmers turned to genetically modified seeds in the 1990s, he continued using traditional seeds, and in 1999 even filed a class-action lawsuit against Monsanto, alleging that the company’s GM seeds were contaminating his own fields.
As a past president of the National Family Farm Coalition, one of the organizations now suing the EPA for approving Enlist Duo, Naylor sees a future in which all farming will be completely industrialized, with everything in the hands of corporations rather than small farmers. Naylor, on the other hand, is trying to convert his own farm to an organic one, but the process has not been easy.
"If you create insecurity in their [farmers'] lives, they will have to make as much money each year as they possibly can, and to do that, you use whatever technology Monsanto or Dow or DuPont put out there,” he says. “The average farmer out there today farms on too big a scale to even think about going organic.”
Farmers didn't follow instructions for dicamba technology
The recent lawsuit that conservation groups filed against EPA for approving Enlist Duo follows similar litigation that they have filed over Monsanto’s Dicamba technology. In that case, the EPA under Obama allowed Monsanto to begin selling Dicamba-resistant seeds before the accompanying herbicide, which is supposed to come with a special nozzle to reduce the risk of drift, was approved. Farmers as a result then turned to other, unapproved dicamba sprays, leading nearby peach farmers and grape growers to complain that their livelihood was being destroyed by dicamba-drift.
One farmer in Missouri was even murdered over fights about drifting dicamba. The complaints led the EPA to launch criminal investigations into dicamba misuse, putting the blame on non-compliance rather than with the product itself. It is an approach that doesn't sit will with people like Sylvia Wu, the attorney with the Center for Food Safety. "Farmers end up with the blame,” she tells ConsumerAffairs, “and the financial harm of misused pesticides.”