Glyphosate has been undes scrutiny since many years. Discovered in 1970 by a scientist at Monsanto, and since commercialization in 1974, its use has grown to dominate the herbicide market.
Over the years, several epidemilogical studies were published, linking the chemical to adverse human health outcomes. Nine epidemiological studies were centered on neurodegenerative outcomes (two high quality), five studies of neurobehavioral outcomes (two high quality), six studies of neurodevelopmental outcomes (none high quality), and five studies of other and mixed neurological outcomes (one high quality). The five high-quality studies showed no association between glyphosate use and risk of depression, Parkinson disease, or peripheral nerve conduction velocity. As for carcinogenicity potential of glyphosate, nine epidemiological studies are published in the public literature, of which 7 case control and 2 cohort. Most studies failed to address potential confounding from other pesticides. Only one study – the US Agricultural Health Study (AHS) – included individuals with relatively frequent exposure to glyphosate and involved comprehensive statistical analyses to address potential confounding by personal factors and other pesticide exposures. The AHS did not find an association between glyphosate and non-Hodgkin’s lymphoma (NHL), even among the most frequently exposed participants (≥ 109 days of use).
In March 2015, the IARC published a summary of their forthcoming monograph on glyphosate, and classified it as “probably carcinogenic in humans” (category 2A) based on epidemiological studies, animal studies, and in vitro studies. It noted that there was “limited evidence” of carcinogenicity in humans for non-Hodgkin lymphoma. It is important to note that the IARC doses not conduct a risk assessment weighing benefits against risk, but rather classifies substances for their carcinogenic potential, only looking at hazards.
Exept for IARC, all other EU and USA agencies did not classified glyphosate as carcinogenic, due to differences in their evaluation of the available evidence. It must be noted that, such agencies also include in their evaluation non-publicly available industry-provided studies (which may be biased in support of their business).
Finally, a recently published landmark long‑term carcinogenicity study by the Ramazzini Institute, referred to Global Glyphosate Study (GGS) has been published. Sprague–Dawley rats were exposed prenatally through adulthood (104 weeks) to glyphosate and two glyphosate‑based herbicides: Roundup Bioflow (EU formulation, POEA‑free) and RangerPro (US form, with POEA) at three doses:
- 0.5 mg/kg bw/day (EU Acceptable Daily Intake, ADI),
- 5 mg/kg bw/day (10× ADI), and
- 50 mg/kg bw/day (the EU NOAEL).
Scientists found out that, even at both the ADI and NOAEL levels, animals displayed statistically significant, dose‑related increases in benign and malignant tumors across numerous tissues: leukemia, skin, liver, thyroid, nervous system, endocrine pancreas, mammary gland, ovary, adrenal, bone, kidney, bladder, spleen, uterus, etc. Interestingly, about 40% of leukemias occurred before age 52 weeks, comparable in human terms to < 35–40 years, a pattern never seen in >1,600 historical controls.
This evidence lends strong support to IARC’s 2015 classification of glyphosate as “probably carcinogenic to humans”, and the authors argue the results now satisfy sufficient evidence in experimental animals.
Additionally, the study found some tumors (eg. adrenal, bladder, kidney) increased only with formulations (GBHs), not glyphosate alone—suggesting co‑formulants might amplify carcinogenic potential.
ADI and NOAEL: What They Are and Why This Study Matters
The EU Acceptable Daily Intake (ADI) for glyphosate is currently set at 0.5 mg/kg bw/day, derived by applying standard uncertainty factors (×100) to a NOAEL of ~50–60 mg/kg in animal studies (53 mg/kg from a dog study; and 59.4 mg/kg from a 2‑year rat study).
The NOAEL reflects the highest dose that did not produce observable adverse effects in standard toxicology testing. In the EU approval process, the NOAEL of ~50 mg/kg bw/day was deemed safe, and the ADI simply divides that by 100 to include human variability and data limitations.
This new study found increased cancer risk at exactly those very doses (ADI and NOAEL), suggesting the current thresholds may no longer be protective, especially considering vulnerable developmental exposures. The fact that both the ADI and the NOAEL induced tumor effects in controlled animal experiments casts serious doubt on the adequacy of the current safety buffer.
Regulatory and Policy Implications in the EU Context
Renewed Approval vs. New Evidence
In 2023, glyphosate was re‑approved for use in the EU until 15 December 2033, following lengthy reviews by EFSA and ECHA which concluded no critical concerns existed under current uses, when good agricultural practices are applied. However, The report also highlighted various gaps in existing data.
Member States may impose additional restrictions, but no outright ban exists at EU‑level. Several countries (e.g. Austria, France, Netherlands) have partial bans in specific settings.
Legal and Scientific Tensions
PAN Europe and associated NGOs filed legal challenges arguing that glyphosate should not have been re‑approved given the available evidence, citing failure to uphold EU law requirements for carcinogenic substances. The Ramazzini data regarging increased blood malignencies were already shared with EU authorities in 2023 but apparently not incorporated into the risk assessment process, as the authoris did not shared the preliminary raw data when requested.
It is also important to notice that the Ramazzini study indicates some tumor types may arise from glyphosate based formulations rather than pure glyphosate alone—meaning EU risk assessments may need to explicitly evaluate full formulations, not just the active substance.
Re‑evaluation
On 25 June 2025, in light of the new results from the Ramazzini study, the European Chemicals Agency (ECHA) formally asked its Committee for Risk Assessment (RAC) to re‑evaluate glyphosate’s classification under Article 77(3)(c) of the REACH Regulation. This mandate reflects newly submitted scientific data—including genotoxicity studies and animal findings not previously assessed—and specifically tasks RAC with reconsidering glyphosate’s classification for carcinogenicity, mutagenicity, and reproductive toxicity under the CLP Regulation (EC No 1272/2008).
RAC has been given a 15-month deadline to deliver its opinion, signalling an expedited process aimed at ensuring EU hazard classification aligns with current scientific evidence.
The mandate covers:
- Evaluation of new in vivo genotoxicity results,
- The Ramazzini-type evidence and other peer-reviewed animal studies,
- A potential recalibration of glyphosate’s hazard classification including carcinogenic (C) and mutagenic (M) categories,
- Possible reconsideration of reproductive toxicity classification.
As of now, glyphosate remains classified only for severe eye damage (H318) and chronic aquatic toxicity (H411); it is not classified as carcinogenic, mutagenic, or repro‑toxic in the EU system.
If RAC recommends classification as a Category 1B carcinogen or mutagen, glyphosate would automatically fail approval criteria under Annex II, points 3.6.2–3.6.4 of the PPP Regulation—unless human exposure can be proven negligible under realistic use conditions.
Final Thoughts
The Ramazzini Institute’s GGS provides robust and alarming evidence that glyphosate, as well as glyphosate-based herbicides, can induce rare and early-onset cancers in animals at exposure levels currently deemed safe in EU regulation. These results challenge the validity of the EU’s existing safety thresholds and open the door to re‑evaluations under pesticide and consumer protection laws. For both policymakers and public health advocates, these findings should act as a catalyst to revisit glyphosate risk assessments and demand greater transparency and precaution in pesticide regulation, particularly in light of real-world evidence linking the compound to adverse health outcomes, like in the case of glyphosate.
Issued by Chiara Gazerro
References:
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European Commission – Glyphosate
ECHA – Note for the attention of Roberto Scazzola, Chairman of the Committee for Risk Assessment
European Food Safety Authority (EFSA), Álvarez, F., Arena, M., Auteri, D., Binaglia, M., Castoldi, A. F., … & Villamar‐Bouza, L. (2023). Peer review of the pesticide risk assessment of the active substance glyphosate. EFSA journal, 21(7), e08164.
EUFIC: Is glyphosate banned in the EU due to its harmful effect, or not?
PAN Europe: New scientific publication confirms glyphosate causes cancer at EU “safe” exposure levels – evidence ignored in EU reapproval.
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