When New Zealand Food Safety announced in October 2025 that it would retain the maximum residue level (MRL) for glyphosate in wheat, barley and oats at 0.1 mg/kg, many people saw it as a victory for public health.
The decision followed strong public opposition to an earlier proposal that could have allowed glyphosate residues at levels up to 100 times higher. More than 3,100 submissions were received, growers and millers were consulted, and the eventual decision was publicly presented as one that maintained New Zealand’s existing protections.
It certainly looked like a meaningful result.
But once you examine where that 0.1 mg/kg limit actually applies — and where it does not — a very different picture begins to emerge.
What “Reasonable Certainty of No Harm” Actually Means
New Zealand’s food safety system — like Australia’s, and the US’s — runs on a risk-based standard sometimes summarised as “reasonable certainty of no harm.” It sounds rigorous. It isn’t a measurement; it’s a judgement call dressed up as one.
- Reasonable — to whom? A regulator working from decades-old industry studies, or a parent feeding a child the same foods every day for eighteen years?
- Certainty — science deals in confidence intervals and evolving evidence, not certainty. Calling a conclusion “certain” is already a stretch.
- No harm — from what, exactly? Usually the isolated active ingredient, tested alone, at a single dose — not the commercial formulation with surfactants, not chronic low-dose exposure, not combination effects with everything else in an ordinary diet.
This differs fundamentally from the precautionary principle — the idea that you don’t approve, or keep approving, a substance until you’re confident it’s safe, rather than approving it until someone proves it’s dangerous. New Zealand markets itself internationally on “clean, green” credentials that sound precautionary. Its regulatory system doesn’t run on precaution. It runs on reasonable certainty — and the October decision shows exactly what that looks like in practice.
What New Zealand Food Safety’s October 2025 Decision Actually Said
New Zealand Food Safety’s own reasoning gives this away. Deputy director-general Vincent Arbuckle stated that the higher limit originally proposed — 100 times higher — would not have presented a health risk either. The limit didn’t stay at 0.1mg/kg because new evidence of harm emerged. It held because growers and millers have increasingly moved to contracts requiring near-zero glyphosate residues anyway, making the stricter limit costless to retain.
In other words: the health question was treated as settled at either limit. Precaution never entered the decision. What actually moved was industry contractual practice — not an independent judgement about what “safe” should mean.
There was one genuine change: glyphosate can no longer be applied directly onto wheat, barley or oats grown for human consumption — only before the crop emerges. That’s worth acknowledging. But it’s also exactly where the “victory” starts to shrink.
The Restriction Only Covers Grain Grown for Human Food
New Zealand’s grain and feed sector produces far less than the country consumes. Of the domestic wheat, barley and oat crop, approximately 9% is typically destined for milling or malting — that is, for human food. The rest goes to animal feed, dominated by the dairy sector (roughly 75% of total grain and feed usage) and poultry (around 12%).
The new spraying restriction is tied specifically to grain “grown for human consumption.” In practice, that’s a small slice of what’s actually grown. And even within that slice, some wheat and barley that starts out intended for milling or malting gets downgraded to feed anyway when weather affects crop quality at harvest — so 9% is a ceiling, not a guarantee.
Most of New Zealand’s Wheat Isn’t Even Grown in New Zealand
New Zealand imports more wheat than it grows. Recent forecasts put wheat imports at around 668,000 tonnes against roughly 419,000 tonnes of domestic production — and the overwhelming majority of those imports come from Australia, historically accounting for around 89% of New Zealand’s wheat imports.
That matters because of how those imports enter the market.
The Trans-Tasman Arrangement: Why Australia’s Higher MRLs Still Apply
Under the Trans-Tasman Mutual Recognition Arrangement (TTMRA), food that can be legally sold in Australia can be legally sold in New Zealand — and vice versa — without needing to separately meet the other country’s standards. This isn’t an oversight being exploited; it’s the arrangement working exactly as designed, and MPI confirms that plant products imported from Australia need only comply with Australian requirements, not New Zealand’s own MRL standard.
Australia’s own MRLs for these crops are dramatically looser than New Zealand’s. Under the current settings:
| Crop | NZ MRL | Australia MRL | Difference |
|---|---|---|---|
| Wheat | 0.1 mg/kg | 5 mg/kg | 50× |
| Barley | 0.1 mg/kg | 20 mg/kg | 200× |
| Oats | 0.1 mg/kg | 0.1 mg/kg | Same |
For wheat and barley, that’s a 50- to 200-fold difference. Grain grown in Australia, sprayed under Australian rules, can arrive in New Zealand and go straight onto supermarket shelves — no additional testing, no requirement to meet the limit New Zealand Food Safety just spent a consultation process defending.
Sorghum and Gluten-Free Weet-Bix: Australia’s MRL Is 150 Times Higher
Sorghum isn’t grown commercially in New Zealand, so it never appeared in the wheat/barley/oats review at all — but it shows up on New Zealand shelves anyway, in imported Australian ingredients. Australia’s glyphosate MRL for sorghum grain sits at 15 mg/kg — 150 times higher than the 0.1 mg/kg limit New Zealand just fought to retain for its own cereal crops.
This isn’t theoretical. NMGNZ’s own independent testing found a gluten-free Weet-Bix product — made from Australian wholegrain sorghum — returning a glyphosate result of 3.9 mg/kg, dramatically higher than any other Weet-Bix variant tested and approximately 39 times the 0.1 mg/kg limit that New Zealand applies to wheat, barley and oats grown for human consumption. That result still sits comfortably under Australia’s 15 mg/kg sorghum MRL, meaning it’s entirely compliant — just not with a standard New Zealand ever agreed to for its own grain.
So What Does New Zealand’s Glyphosate Limit Actually Protect?
New Zealand Food Safety retained the 0.1 mg/kg glyphosate residue limit after a process involving more than 3,100 formal consultation submissions, meetings with industry and a public announcement framed around maintaining protections for consumers.
That formal response was accompanied by an even broader expression of public concern. A parliamentary petition launched by Jade Steel, calling on the Government not to increase glyphosate residue limits in food, received more than 30,000 signatures. Whatever view regulators took of the scientific arguments, that is a substantial number of New Zealanders making their position clear.
But when the retained limit is followed through the food system, its practical reach becomes much smaller than many of those people may have understood.
It applies only to wheat, barley and oats grown in New Zealand for human consumption. That represents only a relatively small proportion of the grain produced domestically, with most destined for animal feed. At the same time, New Zealand imports more wheat than it grows, and those imports — together with products made from ingredients such as Australian sorghum — can legally be sold here under Australia’s residue limits through the Trans-Tasman Mutual Recognition Arrangement.
That doesn’t mean the arrangement is wrong. It is a long-standing reciprocal agreement that supports trade between New Zealand and Australia, and New Zealand exporters benefit from the same framework.
It does, however, raise an obvious question.
If New Zealand’s domestic glyphosate residue limit applies to only a relatively small proportion of the cereal products people actually eat, what role is it really playing?
That isn’t a criticism of the Trans-Tasman arrangement itself. It is a question about transparency. When New Zealand Food Safety announced it was retaining the 0.1 mg/kg limit, many people understandably assumed that decision governed the cereal products on supermarket shelves.
As this article has shown, the reality is more nuanced.
More than 30,000 people signed a petition opposing higher glyphosate residues in New Zealand food. They deserve to understand what the decision made in response to that concern actually changed — and what remained entirely outside its reach.
That is precisely why New Zealand Food Safety should be prepared to explain, in clear terms, what the October 2025 decision changed in practice — and, just as importantly, what it did not.
Further Reading
Want to dig deeper? These pieces cover the testing, the science, and the regulatory gaps behind this story.
Will New Zealand Approve More Glyphosate in Your Food?
NMGNZ’s coverage of the original consultation, before the October 2025 decision — includes links to the MRL database and MPI’s own glyphosate-in-food overview.
Glyphosate Monitoring Failure: Who’s Protecting NZ Food?
Why MPI’s own testing programmes have gone years without checking for glyphosate or its breakdown product AMPA — a companion piece to the “reasonable certainty” argument.
Why Is Gluten-Free Weet-Bix High in Glyphosate?
The independent test result behind the sorghum example in this piece — 3.9 mg/kg in a product made from Australian wholegrain sorghum.
IARC Monograph on Glyphosate
The World Health Organization’s cancer research agency classified glyphosate as “probably carcinogenic to humans” (Group 2A) in 2015 — the scientific backdrop against which “reasonable certainty of no harm” gets decided.
MPI Maximum Residue Levels Database
The official searchable tool for checking New Zealand’s permitted pesticide residue limits, crop by crop — useful for readers who want to verify any MRL figure themselves.
Every regulatory decision covered here is a matter of public record — the more people who read the source material for themselves, the harder these numbers are to quietly walk back.
Image Source & Attribution
The feature image on this page was created using AI-assisted image generation from an original concept developed by No More Glyphosate NZ and refined for publication in Canva.
AI is a useful creative tool for visualising complex investigative topics that cannot be meaningfully photographed, allowing us to illustrate ideas without implying that any specific scene or event actually occurred.
