What Happens When You Go Back and Look Again?
Last year, we took a closer look at one of New Zealand’s most trusted breakfast staples: Weet-Bix.
It wasn’t about proving a point or targeting a brand. It was about something much simpler — asking a question that, surprisingly, hadn’t been asked publicly in a meaningful way: Is there any glyphosate residue in it?
So we tested.
Thanks to a small group of supporters, we were able to carry out our first round of independent testing.
We’re now preparing for a follow-up round — and if you’d like to be part of that, you can support this next phase of testing here: https://donorbox.org/weet-bix-glyphosate-testing
If you prefer to use internet banking, our bank details are available here. Please include Weetbix3 as your reference.
What Our First Weet-Bix Glyphosate Tests Found
Our first round of Weet-Bix-related testing took place in July 2025, when we sent four Sanitarium Weet-Bix varieties to Hill Laboratories for analysis.
Three of those four samples came back with no detectable glyphosate residues at the laboratory’s reporting limit. But one sample — Weet-Bix Multi-Grain, made in Australia — returned a measurable result of 0.56 mg/kg (560 ppb).
Later that month, our broader cereal testing included Woolworths Wheat Biscuits, which returned a much lower result of 0.0082 mg/kg (8.2 ppb).
Taken together, those five results gave us something useful, but not yet conclusive. They suggest that glyphosate residues in this product category may not be uniform. Some samples came back non-detect, one came back very low, and one stood out.
That is exactly why one round of testing is not enough — and why we’re going back to test again.
Why We’re Retesting Weet-Bix for Glyphosate
A single result can tell you what was present in one product, at one point in time, from one batch. What it cannot tell you is whether that result reflects a consistent pattern, a sourcing issue, normal variation between batches, or something else entirely.
That matters, because the difference between 0.0082 mg/kg and 0.56 mg/kg is not trivial. Even within a narrow category of wheat biscuit products, the variation we have already seen raises a fair question: are these residues stable over time, or do they shift depending on supplier, formulation, season, or source country?
This next round of testing is designed to explore exactly that.
Why Repeat Glyphosate Testing Matters
What we’re proposing now isn’t just another round of testing, but the beginning of something more meaningful: repeat testing. Not to confirm a single result, but to understand whether that result holds over time and to ask a better question: Are things changing — or staying the same?
What We’ll Test in Our Next Glyphosate Round
This time, we’re expanding the scope slightly.
Rather than testing just a few selected varieties, we’re focusing on the broader category of “Weet-Bix-style” wheat biscuit products available in New Zealand, including both major brands and supermarket home-brand options.
As always, full product details, batch information, and laboratory results will be published once testing is complete. The goal is not to catch anyone out, but to build a clearer picture of how glyphosate shows up — if it does — across similar products.
Why Glyphosate Testing Matters in New Zealand Right Now
There’s a bigger backdrop to all of this.
Earlier proposals in New Zealand considered raising the allowable glyphosate residue level in wheat from 0.1 mg/kg to 10 mg/kg. In October 2025, New Zealand Food Safety confirmed that the limit would remain at 0.1 mg/kg — and that pre-harvest spraying of glyphosate on wheat, barley, and oats would no longer be permitted.
That decision was welcomed by many. But it wasn’t a complete reset. For dry field peas, the allowable residue level was set at 6 mg/kg, aligning with overseas markets such as the EU, UK, and US. Officials noted this reflects industry practice and the fact that most peas are exported.
Even with tighter domestic settings for some grains, imported products can still exceed New Zealand’s local limits under the Trans-Tasman Mutual Recognition Agreement.
So the issue is no longer just about what’s allowed within New Zealand, but how those standards interact with global supply chains — and what ultimately ends up on supermarket shelves.
What These Results Mean Going Forward
If we’re being honest, this is the point where most investigations stop. A result is published, a conclusion is drawn, and everyone moves on.
But that’s not how systems work, and it’s not how exposure works either.
If glyphosate levels vary, then the only way to understand that variation is to keep measuring — carefully, independently, and over time.
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