Part 3 of our 3-part mini-series on glyphosate, regulatory failure, and why it’s all happening again.
We’ve covered a lot of ground in this mini-series — from the 2017 review the Environmental Protection Authority (EPA) quietly set aside, to the regulatory coziness that shaped how glyphosate was evaluated in New Zealand. And as we arrive at the final chapter, something becomes clear: the issues raised eight years ago aren’t historical footnotes. They’re shaping the EPA’s 2025 legal defence in ways that feel unsettlingly familiar.
The science has moved on.
Public expectations have shifted.
Independent researchers have raised new red flags.
Yet the EPA’s position — the foundation it laid in 2016 and defended again in 2017 — looks much the same today. The same overseas agencies are being relied on. The same assumptions are being repeated. The same gaps remain unaddressed.
It creates a sense of déjà vu, but not the harmless kind.
Because when a regulator keeps returning to the same conclusions despite years of new evidence, it’s no longer just a historical problem — it’s a structural one.
And that’s what this final article explores:
why the EPA’s 2025 court defence echoes the past, and what that says about the future of chemical oversight in New Zealand.
How We Got Here: The Glyphosate Foundation the EPA Never Fixed
In Part 1 – The Review They Ignored, we looked at how the EPA responded after glyphosate was classified as a “probable carcinogen” by the International Agency for Research on Cancer (IARC). Instead of a full, independent reassessment, New Zealand leaned on overseas regulators and declared there was “no new evidence” of risk.
In Part 2 – The Coziness Problem, we dug into how that decision was made — the reliance on industry-aligned agencies, the underfunding, the absence of formulation testing, and a regulatory culture that has quietly come to mirror the language and assumptions of the pesticide industry.
The 2017 Browning–Brunning review [PDF] pulled all of this together and put it on the public record. It didn’t just criticise one decision; it warned that the structure of New Zealand’s chemical oversight would keep producing the same outcomes.
Fast forward to 2025, and we’re watching that prediction play out.
The EPA’s current defence of its glyphosate position still rests on the same foundation it built almost a decade ago. The same reliance on overseas assessments. The same confident assurances that the science has been “carefully reviewed”. The same silence on the formulations actually used here.
The problem isn’t just that those foundations were weak in 2016.
It’s that they’ve never been meaningfully rebuilt.
The 2025 EPA Glyphosate Court Case: What’s Really on Trial?
The Environmental Law Initiative (ELI) case isn’t only about glyphosate.
At its core, it’s asking a bigger question:
Can New Zealand’s regulator rely on inherited overseas decisions, built on industry-supplied data, and still claim to have done an independent, up-to-date assessment for the New Zealand public?
The Court is being asked to examine things like:
- How the EPA weighed independent science versus industry studies and unpublished data
- Whether the 2016 review adequately considered risk, including evidence available at the time
- What has (and hasn’t) been done since — especially as new research has emerged
- Whether the EPA can defend its position today without ever properly examining the formulations actually used in New Zealand
On the surface, it’s a technical case about process.
Underneath, it’s about trust.
Because if the EPA’s original glyphosate decision was built on selective evidence, borrowed conclusions, and untested assumptions, then the problem isn’t just historic. It’s embedded in every reassurance that followed.
That’s what makes this case different from a normal “review and move on” moment.
For once, the EPA isn’t just explaining itself to ministers or the media.
It’s being asked to explain itself to a Court.
Old Glyphosate Conclusions in a New Science Landscape
One of the most striking things about revisiting glyphosate in 2025 is how much the science has moved — and how little the EPA’s position has.
When the EPA decided in 2016 that glyphosate was safe and required no new controls, the conversation was largely framed around:
- cancer
- genotoxicity
- high-dose toxicity
Since then, entire research areas have expanded:
- Endocrine disruption – evidence that glyphosate and some formulation ingredients can interfere with hormones at very low concentrations.
- Reproductive and developmental impacts – studies pointing to effects on fertility, sperm quality, and early embryo development.
- Oxidative stress and mitochondrial dysfunction – mechanisms that can underpin chronic health conditions.
- Gut microbiome disruption – growing concern that glyphosate may affect gut bacteria in ways regulators never evaluated.
- Formulation toxicity – new research showing that surfactants and additives can significantly increase toxicity compared to glyphosate alone.
None of this fits comfortably inside a 2016 conclusion that there was “no new evidence” to worry about — yet the EPA’s public messaging has barely shifted.
The scientific lens has widened.
The regulator’s lens hasn’t.
And that gap keeps getting harder to ignore.
Why Borrowed Glyphosate Assessments Don’t Match New Zealand’s Reality
Another thread running from 2017 to 2025 is New Zealand’s heavy dependence on overseas regulators.
On the surface, it sounds reasonable:
“New Zealand is small. Why redo work already done by larger agencies?”
But as the Browning–Brunning review highlighted — and as the 2025 ELI case is now bringing back into view — this approach rests on assumptions that simply don’t hold. It assumes:
- the products are the same
- the formulations are the same
- the exposure patterns are the same
- the underlying science is transparent and independent
We now know they’re not.
Different countries allow different surfactants and additives. Some formulations sold overseas have been withdrawn or restricted. Others have shifted quietly, with little public documentation. Two herbicides can share the same active ingredient — even the same brand name — yet behave very differently in the body or the environment.
Layer on New Zealand’s own reality — our soils, climate, farming practices, council spray programmes, and lack of ongoing monitoring — and the gaps become even clearer.
So when the EPA leans on overseas summaries that never tested the exact products used here, it isn’t just borrowing science.
It’s inheriting someone else’s blind spots.
Which might be convenient for keeping the system moving.
But it’s not the same as protecting people here.
The Risk of an EPA Stuck Defending the Past
At the heart of all this lies a simple but uncomfortable reality:
A regulator that becomes too attached to its past conclusions stops reviewing and starts defending.
Instead of asking,
“What do we know now?”
it defaults to,
“What did we say before?”
That mindset shows up in subtle ways:
- Framing new evidence as “not enough to change the conclusion” rather than “grounds to revisit the conclusion”
- Treating earlier assessments as settled rather than provisional
- Presenting certainty in public messaging even when the underlying data is incomplete or contested
- Failing to reopen evaluations even as new risk areas — like endocrine disruption — gain scientific recognition
From the outside, it looks like stability.
From the inside, it starts to look like inertia.
The 2017 Browning–Brunning review warned about this exact pattern.
The 2025 court case is, in many ways, a test of whether anything has changed since.
What This Means for Public Trust in Glyphosate Regulation
Most people in New Zealand still assume that:
- regulators test the actual formulations used here
- new science prompts new reviews
- long-term health effects and everyday exposures are fully accounted for
Those assumptions are reasonable.
They’re just not matched by the reality.
When the public finds out that:
- formulations were never properly assessed,
- key decisions relied on overseas agencies later criticised in court,
- and new science has been largely absorbed rather than acted upon,
trust doesn’t erode slowly — it fractures.
That’s why this isn’t “just” about glyphosate.
It’s about whether New Zealanders can believe what they’re told about any chemical regulation.
If a flagship herbicide like glyphosate can go decades without full formulation-level review, while being sprayed around parks, farms, and school grounds, what else has slipped through the cracks?
Where Glyphosate Oversight Leaves New Zealand — and What Needs to Change
The 2025 ELI case is not a magic fix. A single court decision can’t rewrite an entire regulatory culture.
But it can do something important:
force a hard look at the foundations.
If we genuinely want to avoid repeating this history, some changes are hard to avoid:
- Fund the EPA to be independent
Chemical companies should cover the full cost of assessing and reassessing their products. Not as a favour — as a condition of selling them here. User-pays should mean the public doesn’t subsidise safety shortcuts. - Require formulation-level testing
No more pretending that assessing glyphosate on its own tells us what Roundup® or other glyphosate-based weedkillers do in real-world use. The actual products on our shelves and roadsides need to be tested as they’re sold and used. - Build a system that revisits decisions
When new science emerges, reassessment shouldn’t be optional or purely discretionary. There should be clear triggers — like new IARC classifications, major reviews, or significant new evidence of harm. - Reduce dependence on overseas conclusions
International science matters. But New Zealand needs the ability to interrogate, adapt, and, when necessary, disagree — especially when local conditions and formulations differ. - Make the evidence visible
As much as possible, the underlying data behind regulatory decisions should be public. If a chemical’s safety depends on studies no one outside a company or a regulator can see, that’s not public assurance — that’s faith.
These aren’t radical ideas.
They’re the minimum needed for a modern chemical safety system.
Mini-series: Revisiting the Glyphosate Review
This article is Part 3 of our 3-part mini-series on glyphosate regulation, industry influence, and public health oversight in New Zealand.
Part 1: The Review They Ignored — how the EPA dismissed a damning 2017 assessment of its glyphosate review process
Part 2: The Coziness Problem — how industry language and influence shaped our glyphosate assessments
Part 3: History Repeating — (you are here)
Addendum: Missing Science — a standalone analysis examining what was included, excluded, and overlooked in the EPA’s evidence base
Resources & References
The story of glyphosate in New Zealand isn’t just about one herbicide. It’s about how decisions are made, whose evidence counts, and what happens when warnings are ignored for nearly a decade.
These resources help fill in the wider picture:
Public Health Concern: Why Did the NZ EPA Ignore the World Authority on Cancer? [PDF]
The full 2017 review by Steffan Browning and Jodie Bruning, tabled before the Bay of Plenty Regional Council, dissecting the EPA’s glyphosate reassessment.
The EPA’s Glyphosate Review (2016)
New Zealand’s official response to IARC’s classification — a short, selective document that leaned heavily on overseas, industry-linked assessments.
International Agency for Research on Cancer (IARC) – Monograph 112
The 2015 evaluation that classified glyphosate as “probably carcinogenic to humans” after reviewing publicly available, peer-reviewed evidence.
The Monsanto Papers – Carey Gillam
A detailed look at internal corporate documents showing how Monsanto shaped scientific and regulatory narratives around glyphosate worldwide.
Whitewash – Carey Gillam
An in-depth investigation into glyphosate, regulatory capture, and the suppression of inconvenient science.
Court of Appeal to Hear Glyphosate Case – NoMoreGlyphosate.nz
Our coverage of the Environmental Law Initiative’s latest legal challenge — and what it could mean for the EPA, accountability, and public trust.
If the EPA uses this moment to rebuild its foundations, glyphosate might eventually be remembered as the chemical that forced New Zealand to take chemical safety seriously.
If it doesn’t, then history will keep repeating itself — not because we didn’t see the warning signs, but because we chose to look away.
Image Source & Attribution
The feature image on this page was generated using AI (ChatGPT/DALL·E) and adapted for the web using Canva.
