Yes, cooking with aluminum foil can add aluminum to food, but the amount varies widely. Acidic or salty foods, higher temperatures, and longer contact can increase transfer. That does not mean ordinary foil use is inherently unsafe: the amount that migrates depends on the food and conditions, and transfer from foil is only one part of your total dietary exposure. Aluminum is also spelled aluminium in many countries.
Cooking With Aluminum Foil: What Increases Migration?
Aluminum’s surface has a protective oxide layer, but contact with food can still release some metal. Acids such as tomato, citrus, and vinegar can encourage migration; salt can contribute too. Heat and contact time matter, so a hot, acidic dish held against foil for a long time is a different situation from briefly wrapping a cool, relatively neutral food.
A 2019 experiment by Dani Dordevic and colleagues tested 11 foods baked in foil, both marinated and unmarinated, for 40 minutes at 220°C (428°F). The researchers measured aluminum in the food after cooking. Marinated salmon and mackerel showed increases of about 42 and 49 milligrams per kilogram, respectively. The results demonstrate that transfer can be substantial under some tested conditions, not that every food cooked in foil picks up the same amount. The study used particular foods, marinades, and cooking conditions; it cannot predict the amount in every home recipe. Because marinades combined ingredients such as salt and acidic sauces, the experiment also cannot tell you how much each ingredient separately contributed.
In a separate 2018 study, Stefan Sander and colleagues tested uncoated aluminum takeaway trays and reusable camping cookware with acidic foods, including tomato puree and sauerkraut juice. Under time-and-temperature conditions designed to mimic food preparation, storage, and reheating, some tray releases exceeded the Council of Europe’s 5 mg/kg food specific release limit by as much as six times. This was a test of particular uncoated trays and cookware—not a measurement of typical household foil use or a direct estimate of health effects. The European release limit is a food-contact-material benchmark, not a universal boundary between safe and harmful exposure.
What These Findings Mean For Health
Neither experiment shows that using foil occasionally causes illness. The amount that enters your food is not the same as the amount your body absorbs. A 2026 review by Łukasz Kogut and colleagues describes absorption from food as generally low, around 0.1%, while noting that it varies with aluminum’s chemical form and the food matrix. The review concludes that current evidence does not establish that typical dietary exposure directly causes chronic disease; effects associated with unusually high exposure are better established than effects from ordinary long-term dietary exposure.
EFSA has set a tolerable weekly intake of 1 milligram of aluminum per kilogram of body weight, counting exposure from all sources. This is a risk-assessment benchmark for repeated intake, not a target and not a measure of how much foil contributes to a meal. Dietary exposure also comes from aluminum naturally present in food, food additives, and other food-contact materials. EFSA’s assessment noted that available dietary studies could estimate total intake but could not reliably separate these contributions. Exposure varies between people, so a foil experiment alone cannot tell you whether your overall intake is above or below the benchmark.
Simple Ways To Limit Transfer
- For tomato-, citrus-, vinegar-, or salt-heavy dishes, use glass, ceramic, or stainless steel for cooking or storage when convenient.
- If you use foil with an acidic or salty food, avoid leaving it in contact for a long time, especially while the food is hot.
- Use a layer of baking parchment between the food and foil when you want to wrap or cover a dish. This reduces direct contact.
- For less reactive foods and brief contact, there is no need to treat ordinary foil use as automatically unsafe. Focus your changes on repeated, prolonged contact with hot, acidic or salty foods.
Rules and benchmarks for food-contact materials differ by region; the European limit cited above should not be assumed to be a rule in the United States, the United Kingdom, or Australia. If you want more detail about everyday choices, read our guide to cooking with aluminum foil. The evidence supports a measured approach: reduce direct foil contact when food is hot, acidic, salty, or stored for a long time, without assuming that using foil now and then is dangerous.