The Glyphosate Debate

September 14, 2018

Written by Joseph Marchinchin, Turf Care Supply Corp. Agronomist


If you’ve been watching the news as of late, you probably heard about a record lawsuit in California.  A state court recently ordered Monsanto to pay $289 million in damages to a groundskeeper who developed non-Hodgkin’s lymphoma (a form of cancer).  In the landmark case, the plaintiff argued that decades of exposure to RoundUp™ (the trade name for Monsanto’s glyphosate chemistry) led to his medical condition.  After listening to arguments from both sides, a jury of 12 sided with the plaintiff.  Monsanto has already stated multiple times that it will 1.) appeal the decision and 2.) continue to defend the position that glyphosate is a safe chemistry that has been used for decades.  As of September 5, 2018, over 8700 lawsuits have been filed against Monsanto. Regardless of anyone’s opinion on the verdict, there can be no doubt the floodgates have been opened to many more impending lawsuits.  Right now, glyphosate is in the hot seat, but one has to wonder if other pesticides will be next.

Even though Turf Care Supply Corp. does not, and has never offered glyphosate in any of its products, this trending topic has led to a significant increase in customer questions.  Many customers have also inquired whether or not glyphosate is safe to use. Since there are multiple opinions on the topic, we decided to only provide the facts. This way you can decide whether you think it’s safe after we reveal the details of the Glyphosate Debate.

In this feature, we’ll learn how glyphosate works and why it’s been a frequently used tool in ag for many years.  Most importantly, we’ll examine what authoritative bodies have to say regarding whether or not glyphosate is safe.  We’ll also review the precautions consumers should take should they decide to use this herbicide. 



What is glyphosate?

Glyphosate is a non-selective, broad spectrum, systemic herbicide designed to kill most plants.  Glyphosate is an organophosphonate that inhibits an enzyme found only in plants called 5-enolpyruvylshikijmate-3-phosphate synthase.  Essentially, glyphosate prevents plants from being able to synthesize three key aromatic amino acids.  Since amino acids are the building blocks of proteins, and proteins are what catalyze metabolic reactions in all organisms, once plants can no longer synthesize these amino acids, they starve and eventually die.  Glyphosate is applied foliarly and translocated to mitotic sites in the plant. Glyphosate begins to desiccate many plants within 6-12 hours and can kill smaller weeds in only a few days. 


How Did Glyphosate Impact the Ag Industry?

Glyphosate was introduced to the market in 1974 as a means of killing weeds in farm fields.  A few decades later, Monsanto came out with Round-Up™ Readycrops.  These genetically modified crops were given genes that essentially made them resistant to the effects of glyphosate.  The release of RoundUp™ Readycrops was a monumental game changer in ag worldwide; farmers could now spray their fields with glyphosate and effectively kill all the weeds that were competing for space and nutrients withoutharming the crops.  As a result, crop yields increased significantly.  RoundUp™ Ready crops are used all over the world today, and are a key component to helping farmers deliver consistently high yields. 

The success of this technology has also brought about a few challenges. As is with any population within species, genetic variation exists from one organism to another.  Applying this principal on a large scale, it is expected that some weeds are naturally more resistant to glyphosate than others.  For example, in a field of millions of weeds (assuming all of the same species), if a few hundred weeds are glyphosate-resistant, these weeds will breed and produce an entire generation of glyphosate-resistant weeds; hence the problem ofherbicide resistance.  When this occurs, glyphosate’s efficacy becomes markedly reduced or completely inhibited.  Agronomists, geneticists, molecular biologists, and chemists are constantly trying to stay ahead of the resistance curve, as this problem extends to all classes of pesticides (including insecticides and fungicides).  Many are concerned about proliferation of “super-weeds” (or super-resistant weeds) in the ecosystem, making the use of glyphosate on a large scale a topic of controversary.  Although this concern merits discussion, glyphosate is currently in the hot seat because of the accusation that it causes cancer, not that it results in the release of super weeds into the environment. 



Is Glyphosate DANGEROUS or Safe?  Learn what authoritative bodies have to say about it...

Given the recent news, the one lingering question on everyone’s mind is: “Is glyphosate safe?”  In other words, “Does short or long term exposure to glyphosate cause cancer or other adverse effects?” You be the judge! Review the results and responses of authoritative bodies below on the amount of risk they have found glyphosate has to human health (when used as directed). 

IMPORTANT! - As stated before, Turf Care Supply does not offer glyphosate in its product lineup, and thus will reserve an official position on this issue.  We do, however, recommend that you scrutinize these authoritative agencies’ positions, as well as others with differing opinions, and then formulate your own conclusions based on science and factual findings.  The entities listed below were selected without bias. 

  1. Environmental Protection Agency


The draft human health risk assessment concludes that glyphosate is not likely to be carcinogenic to humans.  The Agency’s assessment found no other meaningful risks to human health when the product is used according to the pesticide label.  The Agency’s scientific findings are consistent with the conclusions of science reviews by a number of other countries as well as the 2017 National Institute of Health Agricultural Health Survey.”


  1. National Pesticide Information Center


“Is glyphosate likely to contribute to the development of cancer?

 When high doses were administered to laboratory animals, some studies suggest that glyphosate has carcinogenic potential. Studies on cancer rates in people have provided conflicting results on whether the use of glyphosate containing products is associated with cancer. Some studies have associated glyphosate use with non-Hodgkin lymphoma.

Has anyone studied non-cancer effects from long-term exposure to glyphosate?

Glyphosate exposure has been linked to developmental and reproductive effects at high doses that were administered to rats repeatedly during pregnancy. These doses made the mother rats sick. The rat fetuses gained weight more slowly, and some fetuses had skeletal defects. These effects were not observed at lower doses.  No information was found linking exposure to glyphosate with asthma or other diseases.

Are children more sensitive to glyphosate than adults?

While children may be especially sensitive to pesticidescompared to adults, there are currently no data showing that children have increased sensitivity specifically to glyphosate.”


  1. Canada Pest Management Regulatory Agency


“The overall finding from the re-examination of glyphosate is highlighted as follows:

Glyphosate is not genotoxic and is unlikely to pose a human cancer risk.

Dietary (food and drinking water) exposure associated with the use of glyphosate is not expected to pose a risk of concern to human health.

Occupational and residential risks associated with the use of glyphosate are not of concern, provided that updated label instructions are followed.

The environmental assessment concluded that spray buffer zones are necessary to mitigate potential risks to non-target species (for example, vegetation near treated areas, aquatic invertebrates and fish) from spray drift.

When used according to revised label directions, glyphosate products are not expected to pose risks of concern to the environment.

All registered glyphosate uses have value for weed control in agriculture and non-agricultural land management”



  1. German Federal Institute for Risk Assessment


“The pesticide active ingredient glyphosate has been evaluated by the authorities responsible for the health assessment in national, European and other international institutions, including the WHO / FAO Joint Meeting on Pesticide Residues (JMPR).  After considering all available studies, [glyphosate is] not causing cancer.   This risk is derived from three epidemiological studies from the USA, Canada and Sweden. However, this assessment has not been confirmed in a large cohort of well-cited “Agricultural Health Study” and other studies.  In the current report of the BfR (German Federal Institute for Risk Assessment) in the EU, over 30 epidemiological studies were evaluated. In the overall assessment, there was no validated relationship between Glyphosate exposure and an increased risk of Non-Hodgkin lymphoma or other cancers.”



  1. World Health Organization’s International Agency for Research on Cancer


[As it pertains to glyphosate in drinking water and likelihood of causing different kinds of cancer in human tissues]…

“Because of [glyphosate’s] low toxicity, the health-based value derived for AMPA alone orin combination with glyphosate is orders of magnitude higher than concentrations of glyphosate or AMPA normally found in drinking-water. Under usual conditions, therefore, the presence of glyphosate and AMPA in drinking-water does not represent a hazard to human health. For this reason, the establishment of a formal guideline value for glyphosate and AMPA is not deemed necessary.”




6.1 Cancer in humans

There is limited evidence in humans for the carcinogenicity of glyphosate. A positive association has been observed for non-Hodgkin lymphoma.

6.2 Cancer in experimental animals

There is sufficient evidence in experimental animals for the carcinogenicity of glyphosate.

6.3  Overall evaluation

Glyphosate is probably carcinogenic tohumans (Group 2A).

6.4 Rationale

In making this overall evaluation, the Working Group noted that the mechanistic and other relevant data support the classification of glyphosate in Group 2A. In addition to limited evidence for the carcinogenicity of glyphosate in humans and sufficient evidence for the carcinogenicity of glyphosate in experimental animals, there is strong evidence that glyphosate can operate through two key characteristics of known human carcinogens, and that these can be operative in humans.

Specifically:  There is strong evidence that exposure to glyphosate or glyphosate-based formulations is genotoxic based on studies in humans in vitro and studies in experimental animals.”



  1. European Chemicals Agency


“RAC assessed glyphosate’s hazardousness against the criteria in the Classification, Labelling and Packaging Regulation. They considered extensive scientific data in coming to their opinion. The committee concluded that the scientific evidence available at the moment warrants the following classifications for glyphosate according to the CLP Regulation:

Eye Damage 1; H318 (Causes serious eye damage)

Aquatic Chronic 2; H411 (Toxic to aquatic life with long lasting effects)

RAC concluded that the available scientific evidence did not meet the criteria in the CLP Regulation to classify glyphosate for specific target organ toxicity, or as a carcinogen, as a mutagen or for reproductive toxicity.”




No Matter the Level of Risk you Decide, Taking Proper Precautions is Best

As is with any pesticide, if you chose to use it, make sure you follow the instructions on the label precisely to ensure maximum efficacy and safety. If you have any questions, contact the manufacturer.  Most glyphosate labels will contain the following language:

  • Avoid contact with eyes or clothing.
  • Wear personal protective clothing (wear long-sleeve shirts, pants, socks and shoes).
  • Wash hands thoroughly before eating or drinking
  • Pets:glyphosate is generally non-toxic to dogs, cats, and most domestic animals, however ingestion may lead to mild gastrointestinal irritation.  If swallowed provide animal with adequate drinking water and consult a veterinarian if symptoms persist more than 24 hours
  • Keep container stored away from water, food, feed, or seed. Avoid spills and surface contamination.



Reference images:

Glyphosate 01 (RoundUp) -

Glyphosate 02 (U.S. weed resistance) -

Glyphosate 03 (mode of action) -

Glyphosate 04 (RoundUp Ready Crops) -

Glyphosate 05 (Glyphosate Ruling) -

Glyphosate 06 (how glyphosate resistant crops are made) -

EPA logo -

NPIC logo -

CPMA logo -

German Federal Institute For Risk Assessment logo -

WHO Cancer Research logo -

European Chemicals Agenecy logo -

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