History of Glyphosate in Timeline

Glyphosate is a broad-spectrum systemic herbicide and crop desiccant, functioning as an organophosphorus compound that inhibits the EPSP synthase enzyme in plants. Primarily used to control annual broadleaf weeds and grasses competing with crops, it was commercialized by Monsanto in 1974 under the name Roundup. The U.S. patent for Glyphosate expired in 2000.

1950: First Synthesis of Glyphosate

In 1950, glyphosate was first synthesized by Swiss chemist Henry Martin at Cilag, though the work was never published.

1970: Independent Discovery at Monsanto

In 1970, Glyphosate was independently discovered in the United States at Monsanto as part of research into water-softening agents.

1970: Antimicrobial Activity of Glyphosate Discovery

Since its discovery in 1970 the antimicrobial activity of glyphosate has been described in the microbiology literature.

1972: Description of Glyphosate's Mechanism of Action

In 1972, the description of glyphosate's mechanism of action was published.

1974: Monsanto Introduces Roundup

In 1974, Monsanto first brought glyphosate to market under the Roundup brand name.

1974: Roundup Introduced

In 1974, Monsanto, an American agricultural company, introduced glyphosate for agricultural use under the trade name Roundup.

1987: Franz Receives National Medal of Technology

In 1987, John E. Franz received the National Medal of Technology of the United States for his discoveries related to glyphosate.

1990: Franz Receives Perkin Medal

In 1990, John E. Franz received the Perkin Medal for Applied Chemistry for his discoveries related to glyphosate.

1991: Expiration of Initial Patent

In 1991, Monsanto's initial patent for glyphosate expired.

1993: EPA Considers Glyphosate Noncarcinogenic

In a 1993 review, the EPA considered glyphosate to be noncarcinogenic and relatively low in dermal and oral acute toxicity, with a "worst case" dietary risk model indicating no adverse health effects under maximum residue conditions.

1994: Glyphosate Use in Colombia's Coca Eradication Programs

Since 1994, glyphosate had been used in aerial spraying in Colombia in coca eradication programs.

1996: Commercial Availability of Genetically Modified Soybeans

In 1996, genetically modified soybeans resistant to glyphosate were made commercially available.

1997: US Government Report on POEA Content in Roundup

In 1997, a US government report indicated that Roundup contained 15% POEA, while Roundup Pro contained 14.5% POEA.

September 2000: Expiration of Monsanto's Isopropylamine Salt Patent

In September 2000, Monsanto's patent on the isopropylamine salt of glyphosate expired, ending their exclusive rights in the United States.

2000: Review of Roundup Effects on Organisms

As of 2000, a review of at least 58 studies on the effects of Roundup on various organisms predicted minimal acute and chronic risk for potentially exposed non-target organisms in terrestrial uses.

2000: Expiration of Monsanto's US Patent

In 2000, Monsanto's last commercially relevant United States patent for glyphosate expired.

2003: Study on Glyphosate Formulations and Aquatic Organisms

A 2003 study of various formulations of glyphosate found that risk to aquatic organisms is negligible or small at application rates less than 4 kg/ha and only slightly greater at application rates of 8 kg/ha.

2005: Emergence of Glyphosate-Resistant Weeds

In 2005, a slow upward trend began with glyphosate-resistant weeds appearing rarely around the world.

2007: Glyphosate's Prominence in US Agriculture

In 2007, glyphosate became the most used herbicide in the United States' agricultural sector.

2007: Glyphosate Use in the United States

In 2007, glyphosate was the most used herbicide in the United States agricultural sector, with 180 to 185 million pounds applied.

2007: EPA Selects Glyphosate for EDSP Screening

In 2007, the EPA selected glyphosate for further screening through its Endocrine Disruptor Screening Program (EDSP) based on prevalence of use, not suspicion of endocrine activity.

2008: USDA ARS Describes Glyphosate

In 2008, scientists at the United States Department of Agriculture Agricultural Research Service (USDA ARS) described glyphosate as a "virtually ideal" herbicide.

2010: Glyphosate Products on the Market

As of 2010, more than 750 glyphosate products were on the market worldwide.

2010: Powles' Statement on Glyphosate

In 2010, Powles stated: "glyphosate is a one in a 100-year discovery that is as important for reliable global food production as penicillin is for battling disease."

2010: Trade dispute filed over glyphosate dumping

In 2010, United States companies cited trade issues related to glyphosate being dumped into western world market areas by Chinese companies, leading to the filing of a formal dispute.

2011: Acceleration of Glyphosate Resistance Globally

In 2011, an inflection point occurred and glyphosate resistance accelerated globally.

2012: Global Consumption of Glyphosate

In 2012, about half of the total global consumption of glyphosate by volume was for agricultural crops, with forestry comprising another important market.

2013: Meta-Analysis of Glyphosate-Based Herbicides on Amphibians

A 2013 meta-analysis concluded that glyphosate-based pesticides were not the major cause of amphibian decline, recommending further study of chronic toxicity, environmental glyphosate levels, and ongoing analysis of data to determine glyphosate's role in amphibian decline, including amphibians in standardized test batteries.

2013: German Institute for Risk Assessment (BfR) Examines Glyphosate Studies

In 2013, the German Institute for Risk Assessment (BfR) examined more than 1000 epidemiological studies, animal studies, and in vitro studies related to glyphosate, finding that "no classification and labelling for carcinogenicity is warranted".

January 2014: German Institute for Risk Assessment (BfR) Provides Review to EFSA

In January 2014, the German Institute for Risk Assessment (BfR) provided a systematic review to EFSA that examined over 1000 studies and found that "no classification and labelling for carcinogenicity is warranted".

December 2014: EFSA Publishes BfR Review

In December 2014, EFSA published the review from the German Institute for Risk Assessment (BfR) that examined over 1000 studies and found that "no classification and labelling for carcinogenicity is warranted".

2014: Chinese Manufacturers as Largest Producers

As of 2014, Chinese manufacturers collectively are the world's largest producers of glyphosate and its precursors, accounting for about 30% of global exports.

2014: Glyphosate-Resistant Weeds Dominate Herbicide-Resistance Research

By 2014, glyphosate-resistant weeds dominated herbicide-resistance research, with 23 glyphosate-resistant species found in 18 countries.

March 2015: California OEHHA Announces Plans to List Glyphosate as a Known Carcinogen

In March 2015, the California Office of Environmental Health Hazard Assessment (OEHHA) announced plans to have glyphosate listed as a known carcinogen based on the IARC assessment.

March 2015: IARC Classifies Glyphosate as Probably Carcinogenic

In March 2015, the International Agency for Research on Cancer (IARC) published a summary of their forthcoming monograph on glyphosate, classifying it as "probably carcinogenic in humans" (category 2A) based on epidemiological studies, animal studies, and in vitro studies, noting "limited evidence" of carcinogenicity in humans for non-Hodgkin lymphoma.

March 2015: IARC Classification of Glyphosate

In March 2015, the World Health Organization's International Agency for Research on Cancer (IARC) classified glyphosate as "probably carcinogenic in humans" (category 2A).

May 2015: Colombia Announces Ceasing Glyphosate Use

In May 2015, Colombia announced it would cease using glyphosate in coca eradication programs by October due to concerns about human toxicity.

June 29, 2015: EPA Releases EDSP Tier 1 Screening Conclusions

On June 29, 2015, the EPA released the Weight of Evidence Conclusions of the EDSP Tier 1 screening for glyphosate, recommending that glyphosate not be considered for Tier 2 testing due to lack of evidence of interaction with estrogen, androgen, or thyroid pathways.

November 2015: EFSA Publishes Conclusion on Glyphosate Carcinogenicity

In November 2015, EFSA published its conclusion in the Renewal Assessment Report (RAR), stating glyphosate was "unlikely to pose a carcinogenic hazard to humans".

November 2015: Scientists Criticize EFSA's Decision and BfR Report

In November 2015, an open letter published by 96 scientists criticized EFSA's decision and the BfR report, stating that the BfR report failed to adhere to accepted scientific principles of open and transparent procedures due to unpublished data, lack of authorship, omitted references, and non-disclosure of conflict-of-interest information.

November 2015: European Food Safety Authority Conclusion

In November 2015, the European Food Safety Authority concluded that glyphosate is unlikely to be genotoxic or to pose a carcinogenic threat to humans.

2015: Monsanto Engages Henry Miller to Challenge IARC Report

In 2015, Monsanto engaged Henry Miller to write an opinion piece in Forbes Magazine challenging the IARC report, with Miller not revealing the connection and Forbes removing his blog once this became public.

2015: POEA Commonly Used in Roundup Formulation

In 2015, Polyethoxylated tallow amine (POEA) was commonly used as a surfactant in the original Roundup formulation.

2015: EPA Initiates Review of Glyphosate's Toxicity

In 2015, the EPA initiated a review of glyphosate's toxicity.

2015: IARC Classification of Glyphosate

In 2015, the International Agency for Research on Cancer classified glyphosate in Group 2A, "probably carcinogenic to humans."

2016: Meta-Analysis of Glyphosate's Effect on Soil

A 2016 meta-analysis concluded that at typical application rates glyphosate had no effect on soil microbial biomass or respiration.

2016: Increase in GBHs Usage

From the late 1970s to 2016, there was a 100-fold increase in the frequency and volume of application of Glyphosate-based herbicides worldwide.

2016: Monsanto Starts Case Against California OEHHA

In 2016, Monsanto started a case against the California Office of Environmental Health Hazard Assessment (OEHHA) and its acting director, Lauren Zeise.

2016: Lawsuits against Quaker Oats and General Mills

In 2016, Quaker Oats faced a lawsuit in New York and California federal district courts after trace amounts of glyphosate were found in oatmeal, alleging false advertising of "100% natural". Also in 2016, General Mills removed the "Made with 100% Natural Whole Grain Oats" label from Nature Valley granola bars after a lawsuit claimed the oats contained trace amounts of glyphosate.

2016: EU and Canada Food Products Analysis

In 2016, The EU analysed 6,761 samples of food products for glyphosate residues and Canada surveyed 7,955 samples of food to find glyphosate.

2016: EPA Reports Glyphosate Likely Not Carcinogenic

In 2016, the EPA reported that glyphosate is likely not carcinogenic.

2016: WHO and FAO Report on Glyphosate

In 2016, the WHO and FAO Joint committee on pesticide residues issued a report stating the use of glyphosate formulations does not necessarily constitute a health risk, giving an acceptable daily intake limit of 1 milligram per kilogram of body weight per day for chronic toxicity.

March 15, 2017: ECHA Announces Recommendations on Glyphosate

On March 15, 2017, the European Chemicals Agency (ECHA) announced recommendations from a risk assessment, maintaining the classification of glyphosate as a substance causing serious eye damage and toxic to aquatic life, but not finding evidence of carcinogenicity, mutagenicity, toxicity to reproduction, or toxicity to specific organs.

March 2017: Monsanto Loses Suit Against California OEHHA

In March 2017, Monsanto lost a suit started in 2016 against the California Office of Environmental Health Hazard Assessment (OEHHA) and its acting director, Lauren Zeise.

April 2017: Canadian Government Report on Glyphosate Use

As of April 2017, the Canadian government's Pest Management Regulatory Agency stated that glyphosate was "the most widely used herbicide in Canada" and that approved glyphosate formulations contained less than 20% polyethoxylated tallow amines (POEA surfactants) by weight, finding no risk to humans or the environment at that limit.

September 2017: European Food Safety Authority Publishes Glyphosate Review

In September 2017, the European Food Safety Authority published a review of glyphosate that showed conclusions similar to those of the EPA report, finding no convincing evidence of potential interaction with the estrogen, androgen, or thyroid pathways.

October 2017: Article Reveals Portier's Consulting Contracts and Changes in IARC Report

In October 2017, an article in The Times revealed that Christopher Portier had received consulting contracts with law firms representing alleged glyphosate cancer victims, and that the IARC final report had been changed from an interim report by removing text saying certain studies had found glyphosate was not carcinogenic, and by strengthening a conclusion of "limited evidence of animal carcinogenicity," to "sufficient evidence of animal carcinogenicity".

November 2017: EU Decision on Glyphosate Use Informed by EFSA Report

In November 2017, the EU made its decision on the use of glyphosate, largely informed by the EFSA report which concluded that glyphosate was "unlikely to pose a carcinogenic hazard to humans".

2017: Glyphosate Listed as Known Carcinogen in California

In 2017, Glyphosate was listed as "known to the State of California to cause cancer", requiring warning labels under Proposition 65.

2017: Evidence Reveals Friendly Relationship Between Monsanto and EPA Official

In 2017, evidence collected in a lawsuit brought against Monsanto revealed company emails that appeared to show a friendly relationship with a senior EPA official.

2017: Monsanto Papers Made Public

In 2017, internal documents from Monsanto were made public by lawyers pursuing litigation against the company, who used the term "Monsanto papers" to describe the documents.

2017: ECHA Classification of Glyphosate

In 2017, the European Chemicals Agency (ECHA) classified glyphosate as causing serious eye damage and as toxic to aquatic life but did not find evidence implicating it as a carcinogen, a mutagen, toxic to reproduction, nor toxic to specific organs.

2017: ECHA Risk Assessment

In a 2017 risk assessment, the European Chemicals Agency (ECHA) noted there is very limited information on skin irritation in humans from glyphosate.

February 2018: Injunction Issued Against California's Carcinogenicity Labeling Requirements

In February 2018, as part of an ongoing case, an injunction was issued prohibiting California from enforcing carcinogenicity labeling requirements for glyphosate until the case was resolved, stating that the majority of agencies that have examined glyphosate have determined it is not a cancer risk.

2018: Le Monde Journalists Win European Press Prize for Monsanto Papers Series

In 2018, two journalists from Le Monde won the European Press Prize for a series of articles on the Monsanto Papers, which described, among other things, Monsanto's lawyers' letters demanding that IARC scientists turn over documents relating to Monograph 112, which contained the IARC finding that glyphosate was a "probable carcinogen"; several of the scientists condemned these letters as intimidating.

2018: Glyphosate cancer lawsuits in the United States

Starting in 2018, numerous court cases in the United States involved plaintiffs arguing that their cancer was caused by exposure to glyphosate in glyphosate-based herbicides produced by Monsanto/Bayer. Bayer, the defendant, has paid over $9.6 billion in judgments and settlements but has also won at least 10 cases, arguing successfully that their herbicides were not responsible for the plaintiff's cancer.

August 2019: EPA Disallows Labels Claiming Glyphosate is a Carcinogen

In August 2019, the EPA also said it no longer allowed labels claiming glyphosate is a carcinogen, as those claims would "not meet the labeling requirements of the Federal Insecticide, Fungicide, and Rodenticide Act" and misinform the public.

2020: Evidence for Glyphosate Increasing Cancer Risk

As of 2020, the evidence for long-term exposure to glyphosate increasing the risk of human cancer remains inconclusive.

2022: ECHA Reiterates Findings on Glyphosate's Lack of Carcinogenic Risk

In 2022, the European Chemicals Agency (ECHA) reiterated its findings in a later review, stating that "classifying glyphosate as a carcinogen is not justified" based on a wide-ranging review of scientific evidence.

July 2023: EFSA Re-evaluates Glyphosate's Impact

In July 2023, after three years of assessment, EFSA re-evaluated the impact of glyphosate on human, animal, and environmental health, identifying no critical areas of concern that would prevent glyphosate's registration renewal in the EU.

2023: Prevalence of Herbicide-Tolerant Crops in the US

In 2023, 91% of corn, 95% of soybeans, and 94% of cotton produced in the United States were from strains that were genetically modified to be tolerant to multiple herbicides, including dicamba, glufosinate, and glyphosate.

2024: Meta-Analysis of Glyphosate Effects on Animals

A 2024 meta-analysis of 121 studies determined that glyphosate and glyphosate-based herbicides effects on animals were generally sublethal, with relatively larger effects in aquatic and marine species, though it also found widespread publication bias that may inflate the reported magnitude of these effects.

Mentioned in this timeline

The United States of America is a federal republic located...

California is a U S state on the Pacific Coast...

Colombia is a country in South America with insular regions...

Cancer is a collection of diseases characterized by the uncontrolled...

The World Health Organization WHO is a specialized agency of...

Canada is a North American country the world's second-largest by...