Key takeaways
- Cadmium comes from soil: cacao trees take it up through their roots and store it inside the bean. Lead mostly lands on the outside of beans as they ferment and dry outdoors.
- Cadmium tends to rise with cacao percentage, though the percentage alone can’t rank individual bars. Milk chocolate is generally lower in both metals.
- In Consumer Reports’ 2022 test, 23 of 28 dark chocolate bars went over its daily level for lead, cadmium or both in one ounce. In 2023, 16 of 48 chocolate products did, and none of 5 milk chocolate bars.
- Chocolate is a small part of most people’s cadmium. Grains, leafy greens and potatoes supply more. Treat dark chocolate as an occasional treat and vary what you buy.
How cadmium and lead get into chocolate
Cadmium and lead both turn up in chocolate, but they get in different ways. That’s why different things lower each one.[6]
| Cadmium | Lead | |
|---|---|---|
| Where it comes from | Soil. Cacao trees take it up through their roots. | Soil and dust that stick to beans as they ferment and dry in the open. |
| Where it ends up | Inside the bean, in the nib that becomes chocolate. | Mostly on the outer shell. |
| Darker chocolate | Tends to have more. | Not as closely tied to cacao percentage. |
| What lowers it | Blending beans from lower-cadmium farms; in the long run, soil treatment and new trees. | Keeping beans off the ground while drying, and better cleaning and shell removal. |
Cadmium is generally higher in cacao from Latin America and the Caribbean, where soils tend to have more of it.[6] A 2021 review found that more than half of the Latin American cacao bean samples it compiled had over 0.6 mg/kg of cadmium, a common buying threshold for beans sold to the EU.[7]
Lead works differently. An earlier study found almost none inside cocoa beans but far more on their shells, and concluded that most of the lead gets in during shipping and processing.[8]
What the tests found
In December 2022, Consumer Reports (CR) tested 28 dark chocolate bars. All had detectable cadmium and lead. CR compared one ounce with California’s daily Prop 65 levels for each metal: 0.5 micrograms (µg) of lead and 4.1 µg of cadmium.[1][2]
23 of 28
bars went over CR’s level for at least one metal
5 of 28
went over for both cadmium and lead
5 of 28
were relatively low in both
In 2023, CR tested 48 more chocolate products in seven categories. A third, 16 of 48, went over its level for lead, cadmium or both in a serving.[3]
Products over CR’s level for lead or cadmium, 2023
- Dark chocolate bars5 of 7
- Hot chocolate mixes4 of 6
- Cocoa powder, brownie and cake mixes5 of 18
- Chocolate chips2 of 12
- Milk chocolate bars0 of 5
A 2024 study tested 72 dark chocolate and cocoa products bought between 2014 and 2022. Per labeled serving, 31 of 72 (43%) went over California’s Prop 65 level for lead, and 13 of the 37 with enough data for cadmium (35%) went over its cadmium level. None went over for arsenic. Organic products were linked to higher cadmium; for lead, the results depended on how the authors ran the analysis.[4]
Why darker chocolate has more cadmium
Cadmium lives in the cocoa solids, so the more cocoa a product has, the more cadmium it tends to carry. The FDA says cadmium in chocolate depends on where the cacao was grown and the percentage of cocoa solids.[5] CR found the same pattern for cadmium, but not as much for lead.[1]
The European Union’s limits for cadmium rise with cocoa content for the same reason:
EU maximum levels for cadmium, mg per kg
- Milk chocolate, under 30% cocoa solids0.10
- Chocolate under 50%, or milk chocolate 30% or more0.30
- Cocoa powder sold to consumers0.60
- Chocolate, 50% or more cocoa solids0.80
Cocoa powder is almost all cocoa solids. In the FDA’s Total Diet Study, one of the highest cadmium results was a cocoa powder sample, along with spinach and sunflower seeds, though the FDA tested only one cocoa powder.[10] A serving is small, though, and none of the cocoa powders in CR’s 2023 test were high in cadmium.[3]
How much cadmium is too much?
Cadmium builds up in the body for years. Over time it can damage the kidneys and weaken bones.[11] For people who don’t smoke, food is the main source; smokers get more.[11]
| Benchmark | Amount | For a 150-lb adult |
|---|---|---|
| California Prop 65 level (reproductive harm) | 4.1 µg a day | 4.1 µg a day |
| FDA toxicological reference value | 0.21–0.36 µg per kg of body weight a day | about 14–24 µg a day |
| EFSA tolerable weekly intake | 2.5 µg per kg of body weight a week | about 170 µg a week (24 µg a day) |
Prop 65’s level is the strictest. It’s a benchmark for when a product needs a warning label in California, set at a thousandth of the highest dose with no observed effect in studies, so it isn’t a line where harm begins.[17] It’s also the level CR uses.[2] The FDA and EFSA levels cover cadmium from all foods together, not chocolate alone. A study of U.S. diets from 2007 to 2012 put average intake from food at 4.63 µg a day for people aged 2 and older.[14] For lead, the Prop 65 level is 0.5 µg a day.[12]
Chocolate isn’t where most of that cadmium comes from. The FDA says chocolate is a minor source of cadmium worldwide, and the World Health Organization found cocoa products supplied 0.1% to 9.4% of dietary cadmium in national studies.[5]
Where people in the U.S. get cadmium from food
- Cereals and bread34%
- Leafy vegetables20%
- Potatoes11%
- Legumes and nuts7%
- Stem and root vegetables6%
Is there a limit for cadmium in chocolate?
Not in the U.S. The FDA hasn’t set a cadmium limit for chocolate, though it can act if it finds a food unsafe.[5] For lead, it has had an action level of 0.1 ppm for chocolate and other candy since 2006. All the chocolate and candy samples in its Total Diet Study were below it.[10] Its October 2026 draft cadmium levels cover foods for babies and young children, not chocolate.[15]
Elsewhere, the EU has limited cadmium in chocolate since 2019 (see the chart above).[9] Codex, the international food standards body, recommends 0.7 to 0.9 mg/kg for dark chocolate in trade.[5]
In California, a 2018 legal settlement with chocolate makers sets lead and cadmium levels above which a covered product needs a Prop 65 warning. The levels are higher for darker chocolate, and they step down over time.[16]
How to choose chocolate with less cadmium and lead
- Make dark chocolate an occasional treat, not a daily habit. CR suggests the same.[1]
- Pick a lower cacao percentage when you don’t know a bar’s test results, like 70% over 80% or more. CR notes it isn’t foolproof.[1]
- Don’t assume organic is lower. Organic bars weren’t safer in CR’s tests, and a 2024 study linked organic products with higher cadmium.[1][4]
- Count all your cocoa, including hot cocoa, cocoa powder and brownies. Hot chocolate mixes were among the highest for lead in CR’s 2023 test.[3]
- Go easier for kids and during pregnancy. CR advises giving children little dark chocolate and limiting it while pregnant.[3]
- Ask for test results. Some brands publish lead and cadmium for each batch. Our guide to reading a COA shows how to turn them into micrograms per serving.
Questions people ask
- Why is there cadmium in dark chocolate?
- Cacao trees take up cadmium from the soil through their roots and store it in the beans. Dark chocolate has more cocoa solids than milk chocolate, so it tends to have more cadmium. Cacao from parts of Latin America and the Caribbean is often higher.
- Is dark chocolate high in lead?
- Some is. In Consumer Reports’ 2022 test, all 28 dark chocolate bars had detectable lead, and many had enough that an ounce a day went over California’s strict Prop 65 level of 0.5 micrograms. Lead mostly gets onto beans from soil and dust while they dry after harvest.
- Which chocolate has the least heavy metals?
- Milk chocolate tends to be lowest, because it has less cocoa. None of the five milk chocolate bars in Consumer Reports’ 2023 test went over its levels. Among dark chocolates, a lower cacao percentage is only a rough guide to less cadmium, so use a product’s test results when you can find them.
- How much dark chocolate is safe to eat?
- There’s no official limit for chocolate. Consumer Reports found that an ounce a day of most dark bars it tested went over its strict level for lead or cadmium, and it suggests eating dark chocolate only occasionally. Children and pregnant people should have less.
- Is organic dark chocolate lower in heavy metals?
- Not in the tests so far. Organic bars weren’t safer in Consumer Reports’ 2022 test, and a 2024 study of 72 dark chocolate and cocoa products linked organic ones with higher cadmium. Organic rules don’t limit metals that are already in the soil.
Sources
- [1]Consumer Reports. Lead and cadmium could be in your dark chocolate. December 2022, updated October 2023.
- [2]Consumer Reports. Test methodology for heavy metals in chocolate bars. January 2023.
- [3]Consumer Reports. A third of chocolate products are high in heavy metals, CR’s tests find. October 2023.
- [4]Frontiers in Nutrition. Hands et al., A multi-year heavy metal analysis of 72 dark chocolate and cocoa products in the USA. July 2024.
- [5]U.S. Food and Drug Administration. Cadmium in food and foodwares. accessed October 2026.
- [6]As You Sow and National Confectioners Association. Research identifies ways lead and cadmium in chocolate can be reduced. August 2022.
- [7]Science of the Total Environment. Vanderschueren et al., Mitigating the level of cadmium in cacao products: reviewing the transfer of cadmium from soil to chocolate bar. 2021.
- [8]Environmental Health Perspectives. Rankin et al., Lead contamination in cocoa and cocoa products: isotopic evidence of global contamination. 2005.
- [9]European Union. Commission Regulation (EU) 2023/915 on maximum levels for certain contaminants in food. April 2023.
- [10]U.S. Food and Drug Administration. Total Diet Study elements results summary, FY2018–2020. July 2022.
- [11]Agency for Toxic Substances and Disease Registry. ToxFAQs for cadmium. accessed October 2026.
- [12]California Office of Environmental Health Hazard Assessment. Proposition 65 safe harbor levels. March 2021.
- [13]European Food Safety Authority. EFSA sets lower tolerable intake level for cadmium in food. March 2009.
- [14]Nutrients. Kim et al., Dietary cadmium intake and sources in the US. December 2018.
- [15]U.S. Food and Drug Administration. Draft guidance: Action levels for cadmium in processed food intended for babies and young children. October 2026.
- [16]Superior Court of California, San Francisco. As You Sow v. chocolate makers: Prop 65 consent judgment (modified). February 2018, modified November 2023.
- [17]California Office of Environmental Health Hazard Assessment. Proposition 65 Safe Use Determination (SUD) process. accessed October 2026.
This article is for general information. It is not medical advice and does not replace a doctor, dietitian or pediatrician. Purus gives estimates for general information; it is not a medical device and does not diagnose, treat or prevent any condition.
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