Roundup Revealed: Glyphosate in our Food System

Executive Summary

Glyphosate, the key ingredient in the widely used herbicide Roundup®, has sparked a battle over the future of food. Over the past decade, it has become the most widely used and heavily applied herbicide in history.

The majority of genetically engineered (GE) crops in the U.S. are designed to survive direct applications of glyphosate. As use of GE crops has increased, use of the herbicide has skyrocketed.

A lesser-known use of glyphosate is also attracting scrutiny as it becomes more widespread. Glyphosate is increasingly sprayed on crops like wheat, oats, and beans days prior to harvest to desiccate the plants so harvest operations are easier and can be started earlier. Pre-harvest use results in much higher residues of glyphosate in foods. To address this increase in residues, regulators have consistently raised the legal limits of glyphosate on food crops, despite vigorous public opposition.

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Glyphosate use in the U.S. rose nearly 15-fold between 1996 and 2012.

Source: fotokostic for iStock.

Glyphosate use in the U.S. rose nearly 15-fold between 1996 and 2012.

Two years ago, the World Health Organization’s cancer authority classified glyphosate as a probable human carcinogen. Many countries, communities, and businesses have taken or are considering action to restrict glyphosate use. However, national regulators in the U.S. and EU have historically maintained that glyphosate is safe.

The controversy over glyphosate is located at the nexus of several important trends. Recently, the handful of firms that control world markets in proprietary seeds and pesticides have further consolidated. Some of these companies are staking their futures on new GE crops that are engineered to tolerate not only glyphosate but herbicides that are even more dangerous and volatile. These manufacturers’ goals are in sharp contrast to consumer movements that increasingly value fresh, healthy, and socially beneficial food.

This report tells the story of glyphosate – how and why it is used, what we know about it, and what we do not. It focuses on human health concerns, such as increasing dietary exposures linked to pre-harvest use of glyphosate and the mounting criticism of current U.S. pesticide regulation. The final section outlines our recommendations.

The modern industrial food system, which heavily uses herbicide-resistant GE crops, is increasingly understood to be unsustainable. Investors, companies, and communities will all benefit from a more sustainable food system that will feed the planet today and for generations to come with reduced human and environmental impact.

Key Findings  

Genetically engineered crops are the largest driver of glyphosate sales. Although GE crops were promised to decrease pesticide use and provide a multitude of other benefits, the vast majority of GE crops grown in the U.S. are engineered to tolerate direct applications of glyphosate or to produce Bt insecticide.

Pre-harvest use of glyphosate significantly increases residues of glyphosate in food.

Pre-harvest use of glyphosate significantly increases residues of glyphosate in food. This growing practice increases public health risks, provides farmers with marginal benefit, and has been banned by Germany and Austria. We estimate that 28% of U.S. wheat was treated with glyphosate in 2015, and much of this use may be pre-harvest. As You Sow is working with leading food companies to investigate this practice. For instance, Kellogg Company has agreed to investigate pre-harvest glyphosate use in its supply chain.

The World Health Organization’s (WHO) International Agency for Research on Cancer (IARC), classified glyphosate as a probable human carcinogen in 2015. Research also suggests that glyphosate may have other health impacts including disruption of the endocrine system and other biological processes. These impacts can be amplified by the “inert” ingredients in Roundup and other herbicide products. Independent scientists recommend a limit on glyphosate exposure at least 17 times lower than current U.S. regulation.

Glyphosate is present throughout the food system and our environment. A recent biomonitoring study by UCSF identified glyphosate in 93% of individuals tested and in 60% of surface water in the Midwest. The herbicide has been found to persist in water and soil up to a year in some conditions.


The U.S. Environmental Protection Agency (EPA) maintains that glyphosate is “unlikely to be carcinogenic;” criticism of the EPA’s methods and integrity is growing. In making its determination that glyphosate is unlikely to be carcinogenic, the EPA did not consider the vast majority of academic science and failed to follow its own guidelines, according to its advisory panel. Recently unsealed emails raise concerns about conflicts of interest within the highest levels of the EPA’s Office of Pesticide Programs.

As use of glyphosate has skyrocketed, weeds have developed resistance, with half of U.S. farms reporting glyphosate-resistant “superweeds.” The response of the highly consolidated seed and pesticide industry has been the introduction of new GE crops that are engineered to be used with glyphosate as well as 2,4-D and dicamba. These herbicides are known to be more toxic and volatile than glyphosate. Monsanto, the firm that sells half of the world’s glyphosate, is strategically focused on continuing to sell GE crops that are to be used with herbicides. Now, the company is merging with Bayer, another major seed and pesticide company, which will further decrease competitiveness in the industry and provide greater synergy with the companies’ pesticide sales.

Pesticide-intensive agriculture has been shown to be unnecessary. United Nations food and pollution experts’ 2017 report to the UN Human Rights Council reiterates that pesticides are not necessary to feed the world, warns of catastrophic consequences if current pesticide-intensive farming practices continue, and criticizes pesticide manufacturers for “systematic denial of harms” and “unethical marketing tactics”.

We recommend that investors engage with companies in the food, retail, and restaurant sectors to address the growing risks of glyphosate.

We recommend that investors engage with companies in the food, retail, and restaurant sectors to address the growing risks of glyphosate and other toxic pesticides in the food system. Food companies should mandate reduced use of glyphosate in their supply chains, especially pre-harvest use, and focus on increasing preventive measures such as clear and binding weed resistance prevention plans.

Source: fotokostic for iStock.

Source: fotokostic for iStock.