We buy them almost every week, they cost relatively little and are among the best and most versatile foods we have in the kitchen. But what do the potatoes we find on supermarket shelves really contain? The search for an answer was Il Salvagente, which analyzed 16 samples of fresh potatoes of Italian origin, purchased from supermarkets and discount stores. The results are in many respects reassuring: several products have no detectable residues of pesticides and the concentrations of cadmium, a heavy metal potentially harmful to health, always remain within legal limits. However, there is an exception that deserves attention, given that one champion obtained just 3 points, making him the worst in the test and the only one who failed. The reason? The presence of tetramethrinan insecticide not authorized in the European Union for agricultural use, detected at a concentration significantly higher than the reference limit.
What are the worst potatoes in the test?
The worst rated potatoes were Conad Percorso Qualità, of the Colomba variety, sold at the price of 1.45 euros per kilo. In the sample examined, the laboratory identified 1.2 mg/kg of tetramethrin, a synthetic insecticide belonging to the pyrethroid family and also used in products against mosquitoes and other insects. The substance is not authorized as an active ingredient for agricultural use in the European Union, and the value detected also exceeds the maximum residue limit of 0.01 mg/kg indicated by the magazine by 120 times. This is a significant fact, which led to the rejection of the product. However, it should be noted that exceeding a residue limit does not automatically mean that the health risk is proportional to the exceeding. To assess the possible health hazard, further information on exposure and the toxicological characteristics of the substance is needed.
According to Il Salvagente, the quantity identified could hardly be explained by simple accidental contamination, although the analyses, however, do not allow us to establish with certainty how the insecticide arrived in the potatoes. The magazine reports that it contacted the company to ask for clarification before publication, but did not receive a response. It is important to underline that the result concerns exclusively the sample subjected to analysis and does not demonstrate that all batches of the same product present the same contamination.
Cadmium was also among the substances detected
The failed sample also recorded another data, namely the highest cadmium concentration among those identified in the test, equal to 0.040 mg/kg. Cadmium is a heavy metal that can be absorbed by plants through the soil and accumulate in foods. Prolonged exposure to high quantities can have health consequences, particularly on kidney function. In this case, however, the value found is lower than the maximum legal limit of 0.1 mg/kg foreseen for potatoes. Overall, cadmium was undetectable in 9 out of 16 samples. In the others, the concentrations were between 0.010 and 0.040 mg/kg, without exceeding the regulatory limit.
The other results: ten samples without pesticide residues
Despite the case that emerged, the general picture of the test is decidedly better than one might imagine, because 10 potatoes out of 16 were found to be free of detectable pesticide residues: these included both organic references examined, but also eight conventional products. In the other samples substances such as fosethyl aluminiuma fungicide used to combat some plant diseases, and the propamocarbanother active ingredient with fungicidal function. It was also detectedmaleic hydrazidea growth regulator used to limit sprouting of potatoes during storage. The presence of these residues does not necessarily imply exceeding the legal limits, and to evaluate their relevance it is necessary to consider both the quantities identified and the toxicological profile of the individual substances.
How were the potatoes rated?
To develop the final judgments, Il Salvagente took two main elements into consideration: cadmium contamination, which accounted for 60% of the score, and the presence of pesticide residues, evaluated for the remaining 40%.
For the latter, not only the number of substances identified was considered, but also the risk profile. Penalties have been envisaged for the presence of certain synthetic growth regulators and for any residues detected in products marketed as organic or zero residue. The discovery of an unauthorized pesticide directly led to the rejection.
What does this test really tell us?
The most important fact is that the majority of potatoes analyzed have no detectable pesticide residues, so there is no reason to consider this food generally unsafe. The worst result, however, highlights the importance of checking what reaches our tables, even when it comes to common and apparently unproblematic products. Independent analyzes can identify critical issues that deserve further investigation, even if a single sample does not allow us to establish how extensive a possible problem is along the supply chain.
For consumers, carefully washing potatoes and peeling them when appropriate can help reduce dirt and some surface residues, but does not guarantee the elimination of any contaminants present inside the tuber.
Food safety, moreover, cannot depend only on the precautions taken in the kitchen: it passes above all through controls on the cultivation, conservation and marketing of products.
To find out the complete results of the 16 references analyzed, you can consult the November 2026 issue of Salvagente.
