1 October 2026 | Written by Lucy Bennetto

 

Hello fellow New Zealanders and Aussie cousins,

You may have seen headlines about "heavy metals in chocolate" and wondered what it means for your favourite bar. I wondered too, so we recently sent all four of our plain chocolates to Hill Labs, an independent laboratory in New Zealand, to find out exactly what's in them. I'd love to share what we found, because I think the story behind the numbers is really interesting.

First, how do heavy metals end up in chocolate?

Nobody adds them. Metals like cadmium occur naturally in rocks and soil all over the world. A cocoa tree draws up water and nutrients through its roots, and along with them come tiny traces of whatever minerals are in the ground. Those traces end up in the cocoa bean, and from there in the chocolate. Because it comes from the soil, it can't be washed or roasted out.

This isn't unique to cocoa. Almost everything grown in the ground carries a little cadmium: potatoes, carrots, wheat, rice and leafy greens like spinach. Here in New Zealand, the biggest sources in our diets are actually oysters, potatoes and bread. Chocolate is a very small slice of the pie. Worldwide, cocoa products make up less than 1% of the cadmium people eat.

So why does chocolate get all the headlines? Most of the recent attention traces back to December 2022, when the American magazine Consumer Reports tested 28 dark chocolate bars and reported that 23 of them went over the limits for lead or cadmium in a single ounce (about 28g). The story went around the world. What often got lost was that those limits came from California's Proposition 65 rules, which are among the strictest anywhere and set warning-label thresholds rather than food safety limits. And let's be honest: "Heavy metals found in your favourite chocolate" makes a far juicier headline than "Traces of cadmium found in carrots", even though the carrot story would be just as true!

Why do some growing regions have more than others?

It all comes down to geology. Much of South America's cocoa grows in the shadow of the Andes, where volcanoes have been feeding the soils with minerals for millions of years. These young, mineral-rich volcanic soils naturally hold more cadmium, and slightly acidic soils make it easier for trees to take up. Older, more weathered soils, like those in West Africa and Madagascar, generally hold much less.

You can see this in our own chocolate:

•       Our 70% comes from the UNOCACE Fortaleza cooperatives in Ecuador. It's beautiful fine-flavour cocoa, and being Andean cocoa, it naturally sits at the higher end for cadmium.

•       Our 82% is made with cocoa from Madagascar, where the older soils mean lower levels of cadmium.

•       Our 60% is a blend of Central and South American cocoa, so its levels can shift a little depending on the mix in each batch.

•       Our 43% Creamy range contains less cocoa, so it naturally contains less cadmium.

The rules in New Zealand and Australia

Food Standards Australia New Zealand sets a limit of 0.5mg of cadmium per kilo of chocolate, whatever its cocoa content. That's the maximum allowed in the chocolate itself, and every one of our chocolates sits under it.

You might be surprised to learn the limit for potatoes and leafy greens is lower, at 0.1mg per kilo. That's because we eat potatoes by the kilo and chocolate by the square!

Our results

Each of our 80g bars has 10 squares, so one square weighs 8g.

Chocolate	Cadmium per square	Cadmium per kg (% of legal limit)
43% cocoa	1.3 µg	0.16mg (32%)
60% cocoa	1.8 µg	0.22mg (44%)
70% cocoa	3.4 µg	0.42mg (84%)
82% cocoa	1.6 µg	0.20mg (40%)

(A microgram, µg, is one millionth of a gram. The legal limit in New Zealand and Australia is 0.5mg per kilo.)

So how much chocolate is too much?

This is the question I really wanted to answer for you. The World Health Organization sets a tolerable intake for cadmium: the amount you could take in from your whole diet, every month, for your whole life, without any appreciable risk. For a 70kg adult, that's about 1,750 µg a month, or roughly 400 µg a week.

The good news is that studies of the typical New Zealand diet show it uses only around a quarter of that. To be extra careful, we've assumed your everyday food uses up half, and worked out how much of our chocolate would fit into the other half. For children, whose smaller bodies mean smaller allowances, we've used a quarter of the adult amounts.

Chocolate	Adults (about 70kg), per week	Children (about 20kg), per week
43% cocoa	up to 150 squares (15 bars)	up to 37 squares (about 3½ bars)
60% cocoa	up to 110 squares (11 bars)	up to 27 squares (about 2¾ bars)
70% cocoa	up to 60 squares (6 bars)	up to 15 squares (1½ bars)
82% cocoa	up to 120 squares (12 bars)	up to 30 squares (3 bars)

 

In other words, even with our 70%, an adult could enjoy around 8 squares a day before cadmium became a concern. Your tummy (and your dentist!) would call time long before the cadmium did.

Please note: this guide is our own calculation, based on our September 2026 test results and published data from the World Health Organization and New Zealand's Total Diet Study. It isn't official advice from a food safety authority, and it isn't a nutrition recommendation. Chocolate is a treat, and dark chocolate is best savoured a few squares at a time rather than a whole bar in one sitting. (If you're a milk chocolate fan, you'll know exactly what I'm talking about!)

What about lead, arsenic and mercury?

All were either undetectable or present in the tiniest traces, well under one microgram per square.

The good stuff in cocoa

Of course, cocoa beans take up far more from the soil than just the odd trace of cadmium. Cocoa naturally contains a whole range of minerals, including magnesium, iron and copper. In fact, copper was the biggest number on our lab report, and that's simply cocoa being cocoa. Copper is an essential trace mineral, which means our bodies can't make it and we need to get it from the food we eat. Cocoa beans also contain plant compounds called flavanols, which have been widely studied for their antioxidant properties. The higher the cocoa content, the more of these naturally occurring goodies you'll find, so it's a lovely bonus to enjoy alongside the flavour.

Let's keep this going

These results are from September 2026, and we aim to test our chocolate every year and share the results here. If it's been more than a year and we haven't updated them, please give us a nudge, as life gets busy! And if you have any questions at all, please get in touch. I always love hearing from you.

Lucy