Heavy metals in food databaseFishChecked 2026.10.03
Canned tuna: mercury, lead
In the MHLW compilation, canned tuna has an average total mercury of 0.110 ppm (24 samples), and the guidance for pregnant women also says it can be eaten “as usual.” Japanese cans come as “white meat,” made from albacore, and “light meat,” made from yellowfin, bigeye, and skipjack. However, the national surveys are not broken down by source fish species.
Levels measured in Japanese government surveys and studies
| Metal | Form / state | Mean | Range / max | Samples | Survey |
|---|---|---|---|---|---|
| Mercury | Total mercury, canned tuna in oil (flakes) | 0.110 | max 0.330 | 24 samples | MHLW, compiled through fiscal 2008 |
| Mercury | Methylmercury, canned tuna in oil (flakes) | 0.109 | 0.039–0.336 | 23 samples | MHLW, compiled through fiscal 2008 |
| Lead | Total lead, canned fish (solids; not limited to canned tuna) | 0.01 (median 0.01) | max 0.05 | 40 samples (15 below the limit of quantification) | MAFF, 2020 |
Units are mg/kg (= ppm). The mercury values are for canned tuna flakes in oil, and the sources do not say which fish was used. The lead value is for the solids of canned fish in general, and the products are not limited to tuna.
How much to eat (official advice)
- Canned tuna is said to be fine for pregnant women to eat as usual (MHLW, revised June 2010).
Limits (Japan, international, EU)
| Set by | Limit | Note |
|---|---|---|
| Japan (mercury) | Total mercury 0.4 ppm, methylmercury 0.3 ppm (provisional regulatory limit for fish and shellfish) | Tuna-type fish are exempt. We found no document showing whether it applies to canned tuna. |
| EU (mercury) | 1.0 mg/kg (muscle of tuna) | The value from Regulation 2022/617, carried over into Regulation (EU) 2023/915. Wet weight. We have not confirmed whether canned products fall into this category. |
| US FDA/EPA advice (2021) | Canned light (including skipjack): Best Choices (2–3 times a week). Canned albacore (white): Good Choices (once a week) | Advice for people who are pregnant or breastfeeding and for children aged 1 to 11. One serving is about 113 g (4 ounces). |
| Lead (Codex, EU) | Fish muscle 0.3 mg/kg | Japan has no food-specific limit for lead. We have not confirmed whether the solids of canned food fall into this category. |
Good to know
- In the MHLW compilation, total mercury in canned tuna (flakes in oil) averaged 0.110 ppm, with a maximum of 0.330 ppm. The methylmercury in one serving (about 80 g) is about 8.7 μg, about 8% of the FSCJ’s tolerable weekly intake (111 μg per week for a 55.5 kg person) (Urayomi’s calculation).
- The figures may change with the source fish. In Japan’s market, light meat is said to be a little over 50%, skipjack just under 40%, and white meat just under 10% (quoted from an industry encyclopedia; the year is unknown). The national surveys do not record the source fish of the cans.
- Mercury in albacore (the source of white meat) differs by survey. The MHLW compilation (May 2010) found 0.229 ppm total mercury (21 samples), and the MAFF survey (fiscal 2007–2010) found 0.52 ppm (120 samples). We found no Japanese source that tested canned albacore by species. → Yellowfin tuna, albacore, and young Pacific bluefin
- In US FDA measurements (1991–2010), average total mercury was 0.126 ppm in canned light (545 samples) and 0.350 ppm in canned albacore (451 samples), about 2.8 times higher in albacore. US advice separates the two: light is a Best Choices (2–3 times a week) and albacore is a Good Choices (once a week).
- Lead: in the MAFF survey (2020), the solids of canned fish averaged 0.01 ppm with a maximum of 0.05 ppm (40 samples, of which 15 were below the limit of quantification), and the liquid was below the limit of quantification in all 38 samples. The cans tested are not limited to canned tuna. → Lead: tap water, tableware, cans, and spices
- The mercury compilation runs through fiscal 2008, and the survey for canned tuna is small, with 24 samples (23 for methylmercury). Differences between products or source fish cannot be seen from these figures.
Related explainers
- How Much Fish Is OK During Pregnancy? Guidance for Tuna, Canned Tuna, and Kinmedai, with Mercury Numbers
- Why Do Heavy Metal Standards Differ Between Japan and Other Countries? Japanese, Codex, and EU Standards and Tolerable Intakes Compared
- Lead: Tap Water, Tableware, Cans, and Spices. Where Should You Be Careful? Lead in Food, and Entry Points Other Than Food
Pages for each metal
Sources
- MHLW, “Notes on Eating Fish and Shellfish and Mercury for Pregnant Women” (revised June 2010)
- MHLW, Document 2-4, “Survey Results on Mercury in Fish and Shellfish (Summary)” (May 2010)
- MAFF, “Data Collection of Survey Results on Hazardous Chemicals in Food (Fiscal 2003–2010)”
- MAFF, “Survey on Lead in Processed Foods” (2020)
- US FDA/EPA, “Advice about Eating Fish” (October 2021)
- US FDA, “Mercury Levels in Commercial Fish and Shellfish (1990-2012)”
- European Commission, Regulation (EU) 2022/617 (maximum levels for mercury in food)
Last checked 2026.10.03 (against the original government documents and papers, collected and cross-checked in Gemini Notebook).
Heavy metals occur naturally in soil and the sea, and every food contains small amounts. This page lists facts from government surveys, limits and assessments and from published papers; it does not judge any food as good or bad. Where there is official advice — such as on eating fish during pregnancy — follow it.