The paradox of the precautionary principle. How scare stories about crop chemicals outlive the science

 

Joseph Maina

​​

October 2025

Science for Sustainable Agriculture

Despite overwhelming global scientific consensus affirming the safety of the herbicide glyphosate, activist narratives continue to portray it as dangerous, amplifying a 2015 IARC hazard classification that ignored exposure context. This distortion stems from Europe’s politicised ‘precautionary principle’, which prioritises perceived hazards over proven risks. Activist NGOs and journalists exploit it to sustain headlines and funding, eroding public trust in science. The result: evidence-based regulation is displaced by emotion, undermining both sustainable agricultural innovation and prospects for global food security, writes freelance journalist Joseph Maina.

 

For years, glyphosate has been the world’s most litigated molecule. The herbicide, first brought to market in 1974 under the brand name Roundup, has been reviewed and cleared by regulators on every continent — reaffirmed repeatedly as safe when used as directed.

 

Over the last decade, there have been more than two dozen formal reviews of glyphosate by globally-respected risk agencies, and none has concluded it poses a risk of cancer either to applicators or from micro-trace amounts in our food. That includes assessments by Codex Alimentarius, the FAO, WHO, and regulators from the United States, Canada, Japan, Brazil, New Zealand, Australia, and South Africa.

 

The most extensive review of all was released in 2023 by the European Commission. It took four years to assess more than 180,000 pages of evidence, including 2,500+ scientific studies and the evaluation of more than 12,000 articles. It distilled assessments by both the European Food Safety Authority (EFSA) and the European Chemicals Agency (ECHA).

 

EFSA concluded: “The assessment of the impact of glyphosate on the health of humans, animals and the environment did not identify critical areas of concern.” According to EFSA, “..classifying glyphosate as a carcinogen is not justified.”

 

The evidence is so consistent and overwhelming as to the weedkiller’s comparative safety, that Health Canada wrote in its final report:

 

“No pesticide regulatory authority in the world currently considers glyphosate to be a cancer risk to humans at the levels at which humans are currently exposed.”

 

Still, one would hardly know the overwhelming scientific consensus from the media coverage and blurbs on Facebook, Instagram and TikTok. Rather than quoting the consensus, many journalists, spurred by activist propaganda, describe glyphosate as “probably carcinogenic to humans”—a phrase lifted from a single 2015 “hazard assessment” by the International Agency for Research on Cancer (IARC). That classification never evaluated real-world exposure —what’s called a risk assessment—which is the state-of-the-art evaluation done by every other agency in the world.

 

Examples of five things classified in the same 2A category as glyphosate: eating a hamburger or a pork chop, drinking hot tea or coffee, night work, and visiting your local barbershop or hair stylist.

 

What’s considered even more hazardous, classified as 1? A glass of wine or beer, munching on morning bacon or eating a Christmas ham dinner, or normal outdoor exposure from the sun.

 

In other words, IARC’s assessment are meaningless in assessing real-world risk, as Health Canada wrote in dismissing its finding that glyphosate poses a cancer harm:

 

“Hazard classifications are not the same as health risk assessments. Hazard classifications established by the World Health Organization do not take into account the levels of human exposure, which determines the actual risk.”

 

As part of the re-evaluation decision for glyphosate, Health Canada reviewed the dietary exposure to glyphosate and found that the levels found in food would not be a health risk to Canadians.

 

Yet despite the overwhelming science consensus that glyphosate does not pose a cancer risk, IARC’s misleading hazard assessment has outlived every other piece of science-based evidence.

 

Why do these scare narratives persist?

Part of the answer lies in the structure of modern communication. The first accusation always spreads further than any retraction. The glyphosate scare coincided with a surge in social media activism, where algorithms reward outrage and simplicity over nuance. NGOs and campaign groups seized on the carcinogen label and built entire fundraising and mobilisation campaigns around it.

 

Tort lawyers have scored hundreds of millions of dollars in settlements by convincing scientifically unschooled jurists that IARC’s hazard rating was more credible than the risk assessments of every other science organisation in the world. Their views were propagated by sympathetic journalists, who saw in the controversy a broader moral story about corporate power and environmental neglect.

 

The framing was irresistible: powerful companies versus ordinary citizens. The nuances of toxicology — dose, exposure, and probabilistic risk — did not fit neatly into that template, so they simply ignored it in their reporting. What began as a technical debate became a parable about good and evil.

 

Precautionary principle distorts hazard assessments

But the endurance of misinformation is not just about media incentives. It also reflects Europe’s deeper political identity crisis over the very notion of precaution. Alone among major regulatory blocs, the European Union has moved away from traditional chemical risk assessment — which weighs hazard against real-world exposure — and instead enshrined the precautionary principle as its guiding doctrine.

 

It’s an entirely political choice, which has shaped European policy on chemicals, GMOs, and crop protection products. Activist groups have learned to weaponise this principle, framing every precautionary withdrawal as proof of danger.

 

When regulators withdrew atrazine in 2004 over groundwater concerns, the decision was rooted in environmental persistence, not acute toxicity. But the distinction vanished in activist messaging. “Banned in Europe” became shorthand for “toxic everywhere.” This conflation fostered a moral hierarchy in which Europe’s caution became universal truth, while the rest of the world’s risk-based systems — including those endorsed by FAO and — were recast as reckless or captured by industry. For activist NGOs around the world, stoking outrage about “greedy, chemical-promoting corporations” has become a multi-billion dollar windfall.

 

A similar dynamic unfolded with neonicotinoids, the insecticides blamed for bee declines. Early laboratory studies suggested risks to pollinators, prompting sweeping EU restrictions beginning in 2013. Subsequent field trials revealed a far more complex picture — with factors such as habitat loss, parasites, and viral infections playing significantly larger roles — yet the narrative had already hardened. Headlines still equate neonicotinoids with ecological collapse, even as countries like Canada, Australia, and the U.S. still widely use them under managed conditions.

 

Eroding trust in science

These distortions persist because they are emotionally satisfying. They reinforce a worldview in which precaution equals virtue, industry equals danger, and developing regions that import European or global products are patronisingly portrayed as passive victims rather than sovereign regulators. For campaigners, this framing sustains funding and moral relevance. For journalists, it provides narrative clarity. For policymakers under pressure, it provides the illusion of decisive action.

 

The danger is that such simplifications erode trust in science itself. In Kenya, for example, activists petitioned in 2019 to ban glyphosate and dozens of other pesticides. Agronomists and farmer groups warned of severe yield losses and higher prices. The debate devolved into slogans, drowning out the fact that these same products had been assessed and approved by international agencies operating under WHO–FAO risk frameworks. Similar debates now ripple through Latin America, where precautionary rhetoric imported from Europe is increasingly clashing with local food security needs.

 

The persistence of these myths also reflects a psychological asymmetry: fear is sticky, reassurance is not. Once a compound is branded “carcinogenic” or “bee-killing,” it maintains a cultural life independent of data. Each new lawsuit or NGO campaign revives the stigma, while the science fades into the background. Even when EFSA and ECHA issued what scientists universally hailed as the definitive review of glyphosate in 2023 and found no evidence of genotoxicity or endocrine disruption, few headlines followed and journalists, by and large, continued to push the IARC-activist narrative.

 

Institutional inertia at deepens the problem. NGOs that built their reputations on anti-pesticide campaigns cannot easily pivot when they’ve tied chemophobia to their fundraising. In that sense, the endurance of the glyphosate myth mirrors the persistence of other debunked fears — from GMOs and talc to Tylenol and vaccine conspiracies — each blending genuine concern with symbolic politics.

 

Waking up to conspiracy narratives

Europe’s policymakers may be starting to sense the cynical trap. The EU’s Farm to Fork strategy, which once sought to halve pesticide use (including the use of safe chemicals like glyphosate) by 2030, has been quietly scaled back amid warnings of reduced yields and rising food insecurity. Farmers’ protests across the continent forced the European Parliament to reconsider. The lesson was clear: precaution untethered from evidence can undermine the very sustainability goals it claims to advance.

 

And yet the mythmaking machinery continues to grind on. New campaigns now target what campaigners call “synthetic” agriculture, framing chemical inputs as relics of a toxic age. The implication — that natural equals safe and synthetic equates with dangerous —is scientifically indefensible, although still culturally powerful. It ignores that many of the most toxic substances known are natural, while modern synthetic products are among the most rigorously tested in history, and are, in most cases, less hazardous to farmers and the environment.

 

The endurance of these distortions, then, is not accidental; it reflects a feedback loop between activism, media, and politics, each amplifying the other. Activists supply the narrative, the journalist the platform, and the policymaker the validation. Science becomes a spectator sport.

 

In a world facing food insecurity and shrinking amounts of arable land, the cost of this misperception is not theoretical. When evidence loses to ideology, farmers lose their most effective tools and societies lose resilience. When precaution is weaponised into fear, even legitimate caution begins to look like hysteria.

 

That is the paradox of the pesticide debate: the precautionary principle was meant to protect public confidence in safety. Instead, in the hands of its loudest proponents, it has become a tool of distortion — a principle undermined by those who claim to uphold it.

 

Joseph Maina is an independent journalist based in Naivasha, Kenya.

 

A version of this article was first published by the Genetic Literacy Project here and is reproduced with kind permission.