Glyphosate’s Impact on Human Health and Safety
Glyphosate-based herbicides are among the most widely-used crop protection products in modern agriculture, so it’s understandable that people have questions about their safety, the impact they have on our food supply and our health.
All crop protection products, including glyphosate, are subject to rigorous testing and oversight by regulatory agencies. Glyphosate, given its effectiveness and wide adaptation, is one of the most studied herbicides in the world.
There is an extensive body of research on glyphosate and Bayer’s glyphosate-based herbicides, including more than 800 studies submitted to the U.S. Environmental Protection Agency (EPA), in connection with the registration process, which confirms these products can be used safely and that glyphosate does not cause cancer..
More information on glyphosate’s safety profile is included in the sections below:
The widespread adoption of glyphosate-based products is due not only to their effectiveness and extensive economic and environmental benefits, but also due to the strong safety profile of these products.
When it comes to safety assessments, glyphosate is among the most extensively tested pesticides on the market. Evaluations spanning more than 40 years, and the overwhelming conclusion of experts and regulators worldwide, support the safety of glyphosate and that glyphosate does not cause cancer.
Regulatory authorities routinely review all approved pesticide products. Most recently, in January 2020, the U.S. EPA published its Interim Registration Review Decision on glyphosate and stated “EPA has thoroughly evaluated potential human health risk associated with exposure to glyphosate and determined that there are no risks to human health from the current registered uses of glyphosate and that glyphosate is not likely to be carcinogenic to humans.”
The EPA’s latest decision on glyphosate adds to the overwhelming consensus among leading expert health regulators worldwide for more than 40 years that these products can be used safely, and that glyphosate does not cause cancer. In addition to the U.S. EPA, the European Food Safety Authority (EFSA), the European Chemicals Agency (ECHA), and the leading health authorities in Germany, Australia, Korea, Canada, New Zealand, Japan, and elsewhere around the world continue to conclude that glyphosate-based products are safe when used as directed and that glyphosate does not pose a carcinogenic risk.
What the Experts Say:
Additionally, the most comprehensive epidemiologic study – the independent 2018 National Cancer Institute-supported Agricultural Health Study that followed over 50,000 licensed pesticide applicators for more than 20 years and was published after the IARC monograph – found no association between glyphosate-based herbicides and cancer.6
Glyphosate’s Classification by IARC
One non-regulatory organization presented a classification of glyphosate that was inconsistent with experts and regulatory authorities around the world – this organization was the International Agency for Research on Cancer (IARC), a sub-agency of the World Health Organization (WHO). In March 2015, IARC gave glyphosate a classification of “Category 2A: probably carcinogenic” despite evidence to the contrary. IARC is one of four programs within the WHO that has reviewed glyphosate, and the only one to have made such a finding.
IARC is not a regulatory authority and conducted no independent studies. IARC is the same organization that determined beer, meat, cell phones and hot beverages cause cancer or are likely to cause cancer.
IARC’s opinion is inconsistent with the overwhelming consensus of regulatory authorities and other experts around the world, who have assessed all the studies examined by IARC – and many more – and found that glyphosate presents no carcinogenic risk. Since IARC classified glyphosate in March 2015, regulatory authorities in the United States, Europe, Canada, Korea, Japan, New Zealand and Australia have publicly reaffirmed that glyphosate-based herbicides can be used safely and that glyphosate does not pose a carcinogenic risk.
In January 2020, the U.S. EPA explained that “EPA considered a significantly more extensive and relevant dataset than the International Agency on the Research for Cancer (IARC). EPA’s database includes studies submitted to support registration of glyphosate and studies EPA identified in the open literature. For instance, IARC only considered eight animal carcinogenicity studies while EPA used 15 acceptable carcinogenicity studies. EPA does not agree with IARC’s conclusion that glyphosate is ‘probably carcinogenic to humans.’ EPA’s cancer classification is consistent with other international expert panels and regulatory authorities, including the Canadian Pest Management Regulatory Agency, Australian Pesticide and Veterinary Medicines Authority, European Food Safety Authority, European Chemicals Agency, German Federal Institute for Occupational Safety and Health, New Zealand Environmental Protection Authority, and the Food Safety Commission of Japan and the Joint Food and Agriculture Organization/World Health Organization (FAO/WHO) Meeting on Pesticide Residues (JMPR).”
Before crop protection products like glyphosate can be approved for use, scientific evaluations are conducted to determine potential risk of residues. If the risk is too high, the product never makes it to market.
For products that pass scientific evaluation, the next step is to submit the studies to government regulators who review them and establish their own safe levels of residues, and then constantly monitor harvests to ensure those levels are not exceeded.
All crops will contain trace amounts of elements that are used or present in the environment in which they are grown. Thanks to incredible advances in technology, experts are now able to detect certain substances in units as small as one part per billion. For context, part per billion would be the equivalent of one drop of water in an Olympic-size swimming pool. These advances give scientists great confidence in their ability to ensure that food is safe.
When it comes to pesticide residues, regulatory authorities have strict rules. In fact, the EPA and the EFSA set daily exposure limits 100 times below levels shown to have no negative effect in safety studies.7,8 In the U.S., the Food and Drug Administration (FDA) monitors food to ensure levels stay below the EPA’s limits.
The levels sometimes found in food are incredibly small and nowhere near any level of concern. On Sept. 13, 2019, the U.S. FDA published the results of its annual Pesticide Residue Monitoring Program. The FDA found that all detectable glyphosate residue levels “were below tolerance levels set by the EPA.” Regarding data for pesticides as a whole, the FDA stated that “The findings in this report demonstrate that generally levels of pesticide chemical residues measured by the FDA are below EPA’s tolerances, and therefore at levels that are not concerning for public health.” The FDA’s results are consistent with the findings of other regulatory authorities around the world.
The Basics: Acceptable Daily Intake and Maximum Residue Limits
Acceptable Daily Intake (ADI) , Maximum Residue Limit (MRL), or equivalent limits are established thresholds to help assess any potential risks that could arise from consuming food with residues from certain substances.
- The Acceptable Daily Intake (ADI) value represents the amount of residue that, if ingested daily over a person’s lifetime, is considered to be without significant health risk.
- The Maximum Residue Limit (MRL) value reflects the enforceable maximum level of pesticide residues that are permitted in food or feed based on recommended use.
Any real danger from a potentially toxic substance depends on the dose or the levels at which the substance is present in our environment. While some chemicals, like botulin, are poisonous in small doses; others, like caffeine, are only dangerous at higher doses. Just because a chemical is present does not mean that it is harmful. For example, apple seeds, pears, potatoes and courgettes/zucchini all contain natural chemicals that are potentially toxic to humans. In each of these cases, however, they are usually present in amounts that are far below harmful toxicity levels.
Given the sophisticated technology available, glyphosate has been detected in incredibly small amounts in some foods. The limit on the amounts found in foods (tolerances/MRLs) are not based on safety. They are the maximum amount that can be on the harvested commodity following the approved use from the label. These residue levels are combined with consumption data for the specific crop and added into data for other crops to determine whether human exposures will exceed safe levels. Based on the miniscule amounts in which glyphosate is sometimes found in food, a person would have to consume an incredible amount to get anywhere close to a potentially hazardous level.
Have more questions about glyphosate and our food supply? Keep reading.
- Slate discusses thresholds for which chemicals can become dangerous in food.
- NBC News examines scientific risk assessments and what that means for human health.
- Best Food Facts explores the uses of glyphosate and food safety testing.
- McGill University offers clarity on the science behind evaluating toxicity levels in food and wine.
For farmers working regularly with glyphosate in the field, it’s important to know exactly what impact – if any – this will have on their health.
25-Year Study Follows 50,000 Pesticide Applicators
For more than 20 years, the Agricultural Health Study (AHS)9 has monitored health information from approximately 50,000 pesticide applicators. The study on glyphosate was conducted by independent researchers in academia and/or the U.S. government, and was publicly funded by the National Cancer Institute, the National Institute of Environmental Health Sciences and the National Institute for Occupational Safety and Health, among others – all governmental bodies in the United States.
This particular study was commissioned by the United States government in order to determine the impact of agricultural practices, lifestyle and genetic factors on the health of farmers and their families. In the long-term study, researchers found no association between glyphosate use and cancer.2
Some additional facts about glyphosate safety testing:
- Glyphosate and glyphosate-based herbicides, which have been on the market around the world for more than 40 years, are among the most rigorously studied products of their kind.
- In addition to the rigorous registration that it has goes through in the U.S. and the EU, over its 40 plus year history, glyphosate has been approved for use in 160 countries.
Other resources on this topic:
1 https://www.epa.gov/pesticides/epa-releases-draft-risk-assessments-glyphosate [Retrieved February 12, 2019]
2 https://academic.oup.com/jnci/article/110/5/509/4590280 [Retrieved February 12, 2019]
3 https://www.efsa.europa.eu/sites/default/files/170523-efsa-statement-glyphosate.pdf [Retrieved February 12, 2019]
4 https://www.canada.ca/en/health-canada/news/2019/01/statement-from-health-canada-on-glyphosate.html [Retrieved February 12, 2019]
5 https://www.who.int/foodsafety/jmprsummary2016.pdf?ua=1 [Retrieved February 12, 2019]
6 https://www.ncbi.nlm.nih.gov/pubmed/29136183 [Retrieved February 12, 2019]
7 https://www.epa.gov/iris/reference-dose-rfd-description-and-use-health-risk-assessments[Retrieved February 12, 2019]
9 https://aghealth.nih.gov/ [Retrieved February 12, 2019]