With its ability to prevent food from burning, keep meat tender and conduct heat, aluminum foil is a common kitchen staple with many uses, but you should never use it with certain foods as it can leach toxins into it.
After speaking to a toxicologist and delving into the research, it turns out that certain types of foods – including those that are acidic and heavily salted – can cause this malleable piece of metal to break down and leach toxins into your meal.
To help you avert any risks, a toxicologist explains how and why these foods react with aluminum foil and the implications for your health. Plus, we spoke to a professional chef about the clever non-toxic home essential swaps to make instead.
Foods you should never cook with aluminum foil
There are several things you should never do with aluminum foil, and cooking with it is one of them in many instances.
Dr. Bruce Jarnot, a board-certified toxicologist at Assent explains that ‘Aluminum foil is very useful for many kitchen applications. However, certain foods can cause it to break down. Acidic and heavily salted foods – such as lemon juice, tomato sauce, vinegar, and salt-cured meats and cheeses – can leach aluminum from the foil or cookware.'
Dr. Jarnot explains that this occurs because acids and salts break down the protective oxide layer on the foil, allowing aluminum to leach into items like sliced apples, pickles, feta cheese, or sausages. 'This reaction may introduce a metallic taste into the food and raise potential health concerns,' the expert adds.
Aluminum leaching has been documented in various research papers, including this 2012 study, published in the International Journal of Electrochemical Science, which stated that the amount of aluminum leakage from aluminum foil is found to be 'high' in acidic solutions, and 'even higher' with the addition of spices.
In an earlier 2011 study, it was indicated that a higher rate of leakage was also measured in more salty food. A previous 2006 study also highlighted that high temperatures also have a part to play after researchers noted that when baking food wrapped in aluminum foil at temperatures below 320 ºF (160ºC), the leakage of aluminum was at a lower rate than when baking the same foods at temperatures over 428 °F (220ºC). So do read up on whether or not you can put foil in the air fryer before cooking.
These paper air fryer liners help to prevent food sticking to your air fryer trays without needing foil.
The possible health risks
According to Dr. Jarnot, consuming ‘excessive’ amounts of aluminum has been linked to health risks like osteoporosis (a condition that weakens bones), along with a ‘possible’ connection to Alzheimer’s disease.
The former has been documented in a 2023 article. However, while some studies suggest a link between high aluminum exposure and increased risk of Alzheimer's disease, at the time of writing this, the Centers for Disease Control and Prevention states: ‘We do not know for certain whether aluminum causes Alzheimer's disease.’
That said, according to a 2019 article, aluminum leaching can be hazardous to health when ingesting more than the provisional tolerable weekly intake (PTWI) of two milligrams of aluminum per kilogram of body weight.
What to use instead
There are a number of surprising ways to use aluminum foil around the house beyond cooking. For example, did you know you can clean rust with aluminum foil? Or that you can use aluminum foil for the perfect paint job (and a quick clean-up)?
That said, if used correctly in the kitchen aluminum foil can be safe to use confirms professional chef, Dennis Littley, who is the founder and creator behind Ask Chef Dennis.
He explains, 'It works well for wrapping non-acidic leftovers, tenting meat to retain moisture, and lining baking sheets to prevent messes. It’s also great for steaming fish or keeping food warm after cooking. Just be sure to avoid direct contact with anything highly acidic, as that’s where the risk comes in.’
However, if you're keen to discover other non-toxic alternatives for your acidic cooking creations and food storage ideas, Dennis recommends:
- Parchment paper, like Reynolds Kitchens Pop-Up Sheets from Walmart. Dennis says, 'It's is one of the best choices for baking, roasting, and wrapping food since it creates a barrier without reacting to ingredients. It’s especially great for lining baking trays or wrapping fish and vegetables for steaming in the oven.’
- Silicone baking mats. These are another handy swap and these reusable OXO 11.5"x16.5" Mats, which are BPA-Free, are oven and dishwasher-friendly from Target. Dennis says, ‘Silicone baking mats offer a reusable alternative to foil for baking and roasting, preventing food from sticking while withstanding high temperatures.'
- Glass containers. To store your food, Dennis recommends using glass containers, like PrepNaturals five-star rated 5 Pack of 36 Oz Meal Prep Containers from Walmart, which have smart locking lids and are dishwasher, microwave, freezer, and oven-safe. He explains, ’For food storage, glass containers with airtight lids are an excellent choice because they’re non-reactive, durable, and don’t absorb flavors. They also work for reheating food without the risks that come with plastic or foil.'
- Beeswax wraps. These are another great alternative for covering leftovers. Dennis says, 'They create a breathable seal without the need for disposable materials.' We love these colorful eco-friendly alternatives from Amazon which are crafted from organic cotton, organic jojoba oil, ethically harvested beeswax, and tree resin.
- Grill baskets and grill mats. Dennis adds, 'If you’re looking for a substitute specifically for grilling, grill baskets and stainless steel grill mats allow for easy cooking without direct exposure to aluminum.' This Stainless Steel Barbecue Topper from Target comes with a perforated grid which allows a smoky flavor to infuse in while grease drains away. 'These are especially useful for vegetables and delicate proteins that might otherwise stick to grates,' the chef adds.
Made from heavy-duty 100% natural wood pulp, this unbleached parchment paper is non-toxic so contains no nasties. Coming in a 200 ft long roll, you can cut this to any length.
Meal prep, save leftovers and reheat last night's dinner in these non-toxic glass containers which come in a square, round and rectangular shape.
Keep your food fresh again (and again) with these beeswax wraps which can help you eliminate single-use wrap from your kitchen and give you a non-toxic alternative to storing any acidic foods.
Meet the experts
If you're trying to create a non-toxic household, discover our guide to the best non-toxic air fryers – with stainless steel and ceramic alternatives for health-conscious cooks and our tried and tested explainer on the best non-toxic kitchen appliances.
