Mercury in canned tuna: what the tests show in France
The testing was part of a campaign launched by well-known brand Petit Navire
1 in 10 tuna cans exceed the regulatory threshold for mercury
Gunsales/Shutterstock.
Petit Navire, the canned tuna brand in France, launched a transparency campaign encouraging consumers to send their cans for free mercury testing. Que Choisir, a French consumer association, decided to participate.
The association bought two cans of tuna (one albacore tuna and one yellowfin tuna), filled out the necessary questionnaire, and sent them for testing as part of the campaign called “Take the Test”.
When the results came back, it was confirmed that the cans did contain mercury, although within regulatory limits and at levels permitted for sale. The first of the two cans tested (the albacore tuna) contained 0.27 mg of mercury per kg of tuna, while the second contained 0.45 mg/kg.
The reason behind this relatively high permitted concentration of mercury is that tuna is subject to a standard that is higher than that applied to most other fish: 1 mg/kg compared with 0.3 mg/kg for certain small fish species (such as anchovies and sardines) and 0.5 mg/kg for most other fish.
These regulatory limits apply to fish products in general and are based on fish category rather than packaging form (such as canned or fresh fish).
Despite these levels being compliant with regulations, mercury remains a significant health concern. In fact, the metal is considered “one of the 10 chemicals of serious concern for our health”, as it is associated with toxicity to the central nervous system and can affect brain development in children exposed to it before birth or shortly afterwards.
Moreover, heavy metals, including mercury, are estimated to be in almost all children and adults in France, according to Santé publique France, and are found at higher levels than in most other European countries.
This situation has led the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) to highlight concerns over mercury exposure and recommend limiting intake, especially for vulnerable groups. As of now, an estimated 890,000 children aged 3 to 17 exceed recommended exposure levels, as well as around 1.9 million adults.
This transparency campaign by Petit Navire ran from March 24 to May 5 and was launched in response to a 2024 report by associations Bloom and Foodwatch, which highlighted widespread mercury contamination in tuna and other fish products.
According to Bloom and Foodwatch, 1 in 10 cans exceeds the legal threshold.
In their report called “Poison in Fish”, Bloom and Foodwatch analysed 148 cans of fish from multiple European countries. They reported that all of them contained mercury, with some exceeding regulatory limits.
57% of samples showed mercury above 0.3 mg/kg, and around 1 in 10 exceeded 1 mg/kg (the limit for tuna).
Among these a can of Petit Navire purchased in Paris was found to contain 3.9 mg/kg of mercury (almost four times the legal limit for tuna).
