Does Our Whey Protein Contain Heavy Metals? Here's What The Testing Shows
Heavy metals in protein powder is a fair thing to worry about. Arsenic, cadmium, lead and mercury occur naturally in soil and water, so small traces can turn up in almost any food. The real question is how much.
We sent Clean Nutrition Whey Protein to an independent, accredited New Zealand food testing laboratory to find out. The short answer: all four heavy metals came back below the lowest level the lab can measure, and well under the limits set by the Australia New Zealand Food Standards Code (FSC).
Here's what we tested, what the numbers mean, and why we're sharing them.
How Are Heavy Metals Regulated in New Zealand?
Heavy metals in food sold in New Zealand are regulated under Standard 1.4.1 and Schedule 19 of the Australia New Zealand Food Standards Code[1][2]. The Code sets maximum levels for specific foods where there's a potential risk to public health. For everything else, it requires contaminants to be kept as low as reasonably achievable.
Protein powder doesn't have its own category in Schedule 19. So to give our results some context, we've compared them against the limits the Code sets for other everyday foods:
| Contaminant | Food category | FSC maximum level |
|---|---|---|
| Arsenic | Salt | 0.5 mg/kg |
| Cadmium | Rice and wheat | 0.1 mg/kg |
| Lead | Cereals, pulses and legumes | 0.2 mg/kg |
| Mercury | Salt | 0.1 mg/kg |
Clean Nutrition Whey Protein: Heavy Metal Test Results
The sample was taken from sealed Unflavoured Whey Protein and tested in October 2025. Each metal was measured using ICP-MS (inductively coupled plasma mass spectrometry), a lab method sensitive enough to pick up metals at a few parts per billion.
| Element | Test result | FSC reference limit |
|---|---|---|
| Arsenic (As) | <0.05 mg/kg | 0.5 mg/kg |
| Cadmium (Cd) | <0.002 mg/kg | 0.1 mg/kg |
| Lead (Pb) | <0.01 mg/kg | 0.2 mg/kg |
| Mercury (Hg) | <0.002 mg/kg | 0.1 mg/kg |
View Third-Party Testing Certificate
What Does the "<" Mean?
The "less than" symbol means the metal wasn't detected at or above the lab's limit of quantification (LOQ). That's the smallest amount the test can reliably measure.
So every result above is a ceiling, not an estimate. Even at those ceilings, arsenic sits at under a tenth of its reference limit, lead under a twentieth, and cadmium and mercury under a fiftieth.
Why Is Whey Protein Low in Heavy Metals?
It comes down to where the protein starts. Plants take up minerals, including heavy metals, directly from the soil and water they grow in. That's why plant proteins like pea or rice protein can show small, measurable amounts, depending on where the crop was grown.
Whey is one step removed. It's a by-product of cheesemaking, made from milk. A cow eats pasture, and only a small fraction of any trace metals in her diet ends up in her milk.
Our whey is made from New Zealand grass-fed milk, and there's another layer of checking behind that. New Zealand dairy is monitored through the National Chemical Contaminants Programme (NCCP), run by the Ministry for Primary Industries. The NCCP tests raw milk and dairy products for chemical residues and contaminants, including heavy metals, as part of ongoing national surveillance[3].
A note on flavours: we tested the unflavoured whey, since it's the base protein that goes into every flavour. Our flavoured versions add small amounts of natural flavouring and sweetener, which weren't part of this test.
Is Clean Nutrition Whey Protein Safe?
Based on this testing, yes. All four heavy metals were below detectable levels and well under the Food Standards Code reference limits. That's backed up by the national monitoring New Zealand milk already goes through before it ever becomes whey.
Frequently Asked Questions
Do all protein powders contain heavy metals?
Most foods contain some trace amount, because heavy metals occur naturally in soil and water. The amount varies a lot depending on the protein source and where it's grown. That's why independent testing of the finished product is the only way to know what's actually in a specific powder.
Is whey or plant protein lower in heavy metals?
Plant proteins tend to show more measurable traces, since plants absorb metals directly from soil. That doesn't make plant protein unsafe: our own pea protein testing came in well under the FSC reference limits too. Whey just starts from a source with less direct exposure.
Is Clean Nutrition Whey Protein tested for anything else?
This test looked specifically at arsenic, cadmium, lead and mercury. If you've got questions about other testing, get in touch with our team and we'll happily walk you through it.
References
- Food Standards Australia New Zealand. Australia New Zealand Food Standards Code – Standard 1.4.1 – Contaminants and Natural Toxicants. Federal Register of Legislation. https://www.legislation.gov.au/F2015L00408/latest/text
- Food Standards Australia New Zealand. Australia New Zealand Food Standards Code – Schedule 19 – Maximum levels of contaminants and natural toxicants. Federal Register of Legislation. https://www.legislation.gov.au/F2015L00454/latest/text
- Ministry for Primary Industries. National Chemical Contaminants Programme. https://www.mpi.govt.nz/food-business/dairy-products-processing-manufacture-testing-requirements/monitoring-testing-dairy-products/national-chemical-contaminants-programme