If you’ve watched any television in the past few years, you probably couldn’t have missed getting bombarded with advertisements about class action lawsuits surrounding the Roundup herbicide.  Roundup is one of many popular weed control products on the market today that contains the active ingredient glyphosate.  Because of recent court cases in California, there is a stigma associated with the brand name.  Ironically, no one is talking about the dozens of other brands on the market that carry the exact same chemical, which has been off patent for almost twenty years. 

Glyphosate chemical structure

Glyphosate was discovered in 1950 by a Swiss pharmaceutical company, but had no pharmaceutical properties and was not further pursued for human health purposes. It was ‘rediscovered’ and introduced in the U.S. agricultural market in 1974 as a non-selective herbicide with a new mode of action. Because glyphosate will control broadleaf and grass weeds, it has been used as an integral part of agricultural and landscape weed control for over 40 years with a long-standing history of safe use.

What is the recent controversy about glyphosate? Recently, a California jury awarded $268 million in damages to a plaintiff who claimed that his cancer was caused by glyphosate. This lawsuit is based solely on the opinion of one organization called IARC (International Agency for Research on Cancer, a branch of the World Health Organization). IARC is not a regulatory authority and did no independent studies.

IARC is the same organization that determined beer, meat, cell phones, shift work disorder, working in a salon, and coffee can cause cancer. Investigative reports by Reuters and the Times of London have uncovered that IARC members reviewing glyphosate concealed important scientific data, edited out the conclusions of key studies, and were closely aligned with U.S. trial lawyers.

The National Institutes of Health (NIH) recently reaffirmed glyphosate does not cause cancer. The U.S. Environmental Protection Agency (EPA) and other regulatory authorities in Europe, Canada, Japan, Australia, Korea, and elsewhere routinely review all approved pesticide products and have consistently reaffirmed that glyphosate does not cause cancer.  More than 800 scientific studies, and numerous regulatory authorities around the world have concluded that glyphosate is safe for use and does not cause cancer.

In September of 2016 the U.S. EPA for the third time listed glyphosate as a Group 5 (not likely) carcinogenic substance. This year, glyphosate underwent a U.S. EPA registration review. By law, this occurs for all pesticides on a 15-year cycle to evaluate new scientific data. The results of the re-registration process were that the EPA found – as it has before – that glyphosate is not a carcinogen, and there are no risks to public health when glyphosate is used in accordance with its current label.  It should be obvious the U.S. EPA takes pesticide safety to humans and the environment seriously and is not capricious with their results or rulings. Prior to the U.S. EPA listing glyphosate as a Group 5 substance, in 2015 the European Food Safety Agency (EFSA) “found no grounds to classify glyphosate for carcinogenicity”.

In November 2017 a study was published in the Journal of National Cancer Institute that reviewed the use of glyphosate for 44,932 licensed applicators and users of glyphosate in North Carolina and Iowa. Of the applicators there were 5,779 incidents of cancer, not different from the national average of the population. The authors concluded there was no apparent association “between glyphosate and any solid tumors or lymphoid malignancies overall, including non-Hodgkin’s lymphoma and its subtypes”. 

Does this mean it is safe to use glyphosate? “Safe” is a relative term. All pesticides should be respected and used according to the label. They have been thoroughly tested and reviewed by respectable regulatory agencies (e.g. U.S. EPA and EFSA) for human toxicity and environmental impact. If used correctly, the evidence is that glyphosate is “not likely” to cause issues.  Glyphosate is practically nontoxic to fish, aquatic invertebrates, and honeybees.  In fact, there are several formulations (sold under different brand names) on the market that are labeled for aquatic weed control applications. 

To put all of this into perspective, I like to use this analogy: Does sun exposure cause cancer?  Most people know someone that has gotten skin cancer before.  Just because you’re exposed to the sun (or a pesticide) doesn’t mean you will get cancer.  It all depends on the amount of sun exposure, skin pigmentation, genetics, individual health, severity and frequency of sunburns, etc.  Can you prevent skin cancer?  Absolutely; wear a hat outdoors, where long sleeves, wear sunscreen, eat healthy, and visit a dermatologist periodically. 

These preventative measures for skin cancer aren’t all that different from following the label on many pesticides or pharmaceutical drugs.  Don’t you think it’s a good idea to read and follow the label before taking your medicine?  All pesticides should be treated with the same respect.  Glyphosate is rated as caution, the lowest toxicity rating designated by the EPA.  You still should minimize your exposure and wear gloves and long pants according to the label.  That’s all the label requires, because it’s not any more toxic than many other chemicals or prescription drugs that you’re exposed to every single day. 


Paul Pugliese is the Extension Coordinator and Agricultural & Natural Resources Agent for Bartow County Cooperative Extension, a partnership of The University of Georgia, The U.S. Department of Agriculture, and Bartow County.  For more information and free farm, lawn, or garden publications, call (770) 387-5142 or visit our local website at ugaextension.org/bartow.

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