Safe to Use as Directed: Understanding Glyphosate Myths

Brian German Agri-Business, Industry

Glyphosate myths continue to remain in the public eye through news reports, social media, and multiple court cases centered on its use in agriculture.  The material that has been around for more than four decades has become a hot topic of debate over the past few years, with supporters of glyphosate products and opponents both adamant in their arguments.  Regardless of the passion surrounding the idea of safety concerning glyphosate or its alleged potential for causing cancer, the scientific verification remains unwavering.   

“There have been multiple studies on glyphosate and glyphosate-based herbicides – so both the formulated product and the just active ingredient – and there is no association between glyphosate and any kind of cancer,” said Liza Dunn, Medical Affairs Lead for Bayer Crop Science.  “This has been looked at by regulatory agencies all over the world.”

Dunn speaking to winegrape growers and pest control advisors in Monterey.

Much of the argument pointing to glyphosate as a carcinogen revolves around an article that was published in a well-respected medical journal in 2015. When the International Agency for Research on Cancer published a monograph on glyphosate in The Lancet, it was misclassified as an insecticide instead of rightfully classifying glyphosate as an herbicide.  The misclassification of glyphosate caused subsequent medical professionals to look at the material with a misunderstanding of its toxicity profile.  The misrepresentation of glyphosate has since helped usher in several lawsuits in recent years asserting that the material caused cancer.

“We are vigorously defending our product because we know it’s not a carcinogen and we know how critical it is for agriculture,” Dunn noted.  “We’ve had the California Medical Association, the California Dental Association, and the California Hospital Association file an amicus brief on our behalf because they understand how important it is to have scientific credibility determine court cases.”


One of the glyphosate myths is that there simply has not been sufficient scientific study that can definitively determine if the material is or is not a carcinogen. Dunn pointed out that the material is registered in more than 160 countries around that world, which requires a review of all the information that is available.  When a product is up for reregistration every ten to 15 years depending on the country, it undergoes yet another review incorporating all the scientific studies related to the material.  “It turns out that glyphosate has been looked at every three to five years because it’s registered in so many countries,” Dunn explained.

The article published in 2015 also prompted the rereview of the material by multiple different agencies.  The U.S. Environmental Protection Agency (EPA) even convened a cancer committee specifically assembled to address the potential that glyphosate might be a carcinogen.  Dunn explained that the committee reviewed hundreds upon hundreds of studies related to the material. Despite the EPA’s review which found glyphosate to be a safe material to use, another one of the glyphosate myths that continues to linger is that EPA will no longer be allowing glyphosate registrations. “That is not true. The EPA has come out publicly and said that glyphosate-based herbicides are not carcinogenic, and they are safe to use as directed.  You don’t need to worry about health effects associated with using glyphosate-based herbicides,” said Dunn.


Glyphosate has been on the market for nearly 45 years and has proved to be an essential material in agricultural systems around the world.  The efficacy of the material in combatting weeds in various types of crops has helped to revolutionize farming in some parts of the world that had previously not experienced that level of agricultural production. Dunn noted that farmers have more than 10,000 years of organic production experience, but it has only been in the last 50 years that there has been food security in the West.  Scientific and technological advancements play a critical role in moving agricultural production forward to be able to meet the needs of an ever-expanding world population. 

“That’s because of the scientific advances in agriculture that have profoundly changed it and glyphosate is one of those key things, key chemicals that’s part of those scientific advances,” Dunn explained.  “Glyphosate actually turns out to be the foundation of American agriculture, both North and South America and indeed worldwide; and it’s as critical to agriculture as antibiotics are to medicine.”

Listen to the interview below.

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Brian German

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Ag News Director, AgNet West